Search Results for 'pathfinder epidemiology'


Introduction

In previous posts in this series, I showed the differences between fighter builds, and especially that “fast fighters” are a weak decision that is particularly bad for halflings and elves even though they are the more agile races. In this post I will approach the question of fighter builds from a different angle, that of the most effective choice of feats, armour and weapons for given attribute scores. Ultimately, the aim of this work is to develop decision models (expressed as flowcharts) for PC development. We will do this through a generalized version of the simulations run to date, in combination with classification and regression tree (CART) methods.

Methods

For this study a completely random character generation method was developed. This simulation program generated random races, ability scores, weapon and armour types and feats subject to the rules in the online Pathfinder System Reference Document (SRD). Weapons were restricted to three choices: rapier, longsword and two-handed sword. Armour types were studded leather, scale, chain shirt and chain mail. There were eight possible feats: improved initiative, dodge, shield focus, weapon focus, power attack, desperate battler, weapon finesse and toughness. Ability scores were generated uniformly within the range 9 to 18, and racial modifiers then applied: the human +2 bonus was applied randomly to the three physical attributes. Feats were assigned randomly, with humans having three feats and non-humans two. All fighters with a one-handed weapon were given a light wooden shield. Halflings were given size benefits and disadvantages as described in the SRD. Initial investigation revealed that ability score values were only important in broad categories: ability scores that gave bonuses greater than 0 were good, and bonuses of 0 or less were bad. For further analysis, therefore, all ability scores were categorized accordingly into values of that gave a bonus of +1 or greater vs. those that did not.

All fighters were pitted in one-to-one melee combat against an Orc, which had randomly determined hit points and the fully operative ferocity special ability. This happened in a cage deep beneath Waterdeep, so no one could run away. Winners were promised a stash of gold and the chance to buy a farm on the Sword Coast, but were actually subsequently press-ganged into military service in the far south, where most of them died of dysentery. A million fights were simulated.

Once data had been collected it was analyzed using classification and regression tree (CART) models implemented in R. CART models enable data to be divided into groups based on patterns within the predictor variables, which enables complex classification and decision rules to be made. Although it is more complex and less reliable than standard regression, CART enables the data to be divided into classification groups without the formulaic restrictions of classical linear models. Results of CART models can be expressed as a kind of flowchart describing the relationship between variables, with ultimate classification giving an estimate of the probability of observing the outcome. In this case the outcome was a horrible death at the hands of an enraged orc, and the probability of this outcome is expressed as a number between 0 and 1. CART results were presented separately by race, in case different races benefited from different choices of feats.

Some univariate analysis was also conducted to show the basic outline of some of the (complex) relationships between variables in this dataset. Univariate analysis was conducted in Stata, and CART was conducted in R.

Results

Of the million brave souls who “agreed” to participate in this experiment, 498000 (49.8%) survived. Survival varied by race, with 55% of humans surviving and only 45% of halflings making it out alive. Some initial analysis of proportions suggested quite contradictory results for the different feats, with some feats appearing to increase mortality. For example, 47% of those with improved initiative survived, compared to 51% of those without; and 46% of those with shield focus, compared to 52% of those without. This probably represents the opportunity cost of choosing these feats, or some unexpected confounding effect from some other variable.

The three combinations of ability scores and feats with the highest number of observations and the best survival rate were:

  • Dwarf with +3 strength, +3 dexterity, +3 constitution, chain mail armour, rapier, weapon focus and desperate battler (15 observations, 100% survival)
  • Dwarf with +3 strength, +0 dex, +4 con, scale armour, two-handed sword, toughness and weapon focus (13 observations, 100% survival)
  • Dwarf with +3 strength, +2 dex, +3 con, studded leather armour, longsword, desperate battler and power strike (13 observations, 100% survival)

Despite the apparent success of Dwarves, a total of 55% of all unique combinations of ability scores, feats, weapon and armour types with 100% survival were in humans. The majority of the most frequent survival categories appeared to be in non-humans, however – this bears further investigation.

CART results varied by race. For humans, ability scores were most important; for dwarves, weapon type and armour type were important, while constitution was largely irrelevant. For elves and halflings, the only important feat was toughness; weapon finesse was only important for humans, and sometimes only as a negative choice. The key results from the CART analysis were that strength is the single most important variable, followed by dexterity for elves and halflings, or constitution for dwarves; and then by decisions about armour and weapons. Feats are largely relevant only for those with weak ability scores.

As an example, the CART results for humans are presented as a flowchart in Figure 1 (click to enlarge). It is clear that after strength and dexterity, heavy armour and constitution are important determinants of survival. Weapon finesse is only important as a feat to avoid for those with low dexterity – for those with high dexterity it is largely irrelevant. Toughness primarily acts as a counter-balance to poor constitution in those with high dexterity and strength.

Figure 1: Character creation decision model for humans

Decision models for other races will be uploaded in future posts.

Conclusion

This study once again shows that strength is the single most important ability for determining survival in first level fighters, and that feats are largely used to improve survival chances amongst those who already have good ability scores. In previous posts dexterity appeared to be irrelevant, but analysis with CART shows that the absence of a dexterity bonus makes a large difference to survival – those with no dexterity score bonus do not benefit from feat choices, while those who have a dexterity bonus can benefit further by careful choice of armour and feats. Although previous posts found that “tough” fighters have a very high survival rate, this post finds that constitution is not in itself a priority ability score. By following the decision model identified in this study, players can expect to generate a fighter with the highest average survival chance given their ability scores.

This weekend I continued my work on the epidemiology of Pathfinder, including an expansion of my programs to allow for different types of point buy. In the process I took the advice of some commenters at a related thread on the Pathfinder message boards:

I think for the non human fast fighters dropping weapon finesse makes no sense. Because they can hardly hit if they drop that. I would recommend changing it to dropping improved initiative for the fast non-humans.

In my original simulations I had built non-human fast fighters with improved initiative and weapon focus, but in this revision I changed this around so that non-human fast fighters drop improved initiative and keep weapon finesse. The results, though still not presenting a stirring defense of the decision to play a fast rather than a strong fighter, do bear out the suspicions of those commenting on that board, that for fast fighters weapon finesse is the most important feat to choose. Table 1 compares the results with weapon finesse that I generated today with the previous set of results that dropped weapon finesse in favour of improved initiative. The results in Table 1 are shown for combat with meek orcs (lacking ferocity) to be consistent with the previous post. Similar effects are observed against ferocious orcs, however.
Table 1: Non-human mortality with and without weapon finesse (revised)

Race No Weapon Finesse Weapon Finesse Odds Ratio
Dwarf 43.6 37.0 1.32
Elven Ponce 52.2 44.2 1.38
Halfling Loser 61.6 49.7 1.62

The odds ratios in Table 1 are provided to show which race suffers the most from lack of weapon finesse, and it is no surprise that it is the halflings. This is because they do the least damage, so the loss of hit chances affects them the most.

These results don’t change the fundamental conclusion that fast fighters are a very bad choice, but they do indicate that if one is going to pick this fighter build, weapon finesse is a very important feat to choose.

Continuing my series of posts exploring the epidemiology of Pathfinder, today I will report on the impact of adding ferocity to the orc stat block. Is the orc still a CR 1/3 monster when one accounts for ferocity, and just how tough does a fighter have to be to walk away from a fight with a single ferocious orc?

For this simulation (and all sims from now on) I am going to be using my updated and revised modeling program, which has been subject to some fairly severe stress tests and which I’m now fairly certain perfectly mimics a basic combat exchange between an orc and a fighter. I posted revisions here, showing the basic survival probability for three types of fighter and four races, for an orc with no ferocity. This is the basic program I’ll be working with from now on.

Introduction

Previous analysis of survival in Pathfinder have studied conflict between fighters of the four main races and inferior breeds of orc, but it is likely that serious dungeoneering will bring adventurers into conflict with hardier orcs fighting near their lair. It is well known that orcs who maintain a close cultural connection with their tribe are braver and more determined fighters, and this is usually reflected in their ability to fight even when suffering serious physical injuries. For this analysis, this powerful additional trait of “wild” orcs, ferocity, is included in the analysis. Essentially this analysis compares the survival chance of a lone fighter against a lone orc isolated from its tribe, probably in a city, with a lone fighter in combat with a lone orc near its lair, where it will fight beyond death.

Methods

A set of 200,000 simulated battles between randomly-generated fighters and randomly-generated orcs was analyzed using poisson regression. Orcs and fighters were generated in the standard way, but orcs had a 50% chance of having the ferocity trait, which enables them to continue fighting until they reach -12 hps. A simple main-effects poisson regression model of survival was built, and the effect of orc ferocity on survival reported from this model; subsequently, a model with interactions between ferocity and all the main variables of interest (fighter type, race and ability bonuses) was also built. Results from both of these models are reported selectively for simplicity.

Results

Mortality for the 100,000 fighters against meek orcs was unchanged, at 37.2%; but for fighters battling ferocious orcs mortality increased significantly, to 63%. Patterns of mortality differences by race and class type were similar to those seen previously, but mortality rates were higher in all class types and races. Table 1 shows mortality rates by race and ferocity type.

Table 1: Mortality rates by race and orc ferocity

Race

Orc Ferocity

Meek Ferocious
Human 30.6 57.1
Dwarf 32.4 60.1
Elven ponce 40.8 65.8
Halfling loser 44.9 68.2

Note that, although survival patterns are maintained in battles against ferocious orcs, the mortality ratios decrease: from a 50% increase in mortality between humans and halflings against meek orcs, for example, to a 20% increase against ferocious orcs. The increase in mortality due to ferocity also varies, from nearly a two-fold increased mortality rate in humans and dwarves to only a 50% increased mortality amongst halflings.

In a simple main-effects poisson regression model ferocity was associated with an average relative risk of mortality of 1.7, which was highly statistically significant (Z=80.12, p value <0.0001). That is, the average increased mortality from adding ferocity to an orc stat block was about 70%. However, in a model including interaction terms between orc ferocity and all main variables (fighter type, race, and all three stat bonuses) the role of orc ferocity varied significantly across ability scores. For example, after adjusting for other ability scores, class type and race, the increased mortality amongst fighters with minimum strength bonus was only 20%, while it was 85% for fighters with a strength bonus of +5. This effect is shown in Figure 1, which plots the relative risk of mortality by strength score for meek compared to ferocious orcs. All relative risks are relative to a fighter with a strength of -2.

Figure 1: Mortality by Strength Ability Score for Meek and Ferocious Orcs

Essentially, strength induces a lower gradient of mortality improvements when fighting tough orcs, and combinations of high scores become more important. In fact, it seems highly unlikely that decent survival will be obtainable for fighters of any race and class type generated using Pathfinder’s standard point-buy systems. These systems will restrict most PCs to ability scores in the 14-16 range, which will not guarantee survival against even a single ferocious orcs.

Conclusion

Adding ferocity to an orc’s stat block significantly increases its lethality, with an average increase in mortality risk for fighters in one-to-one combat of about 70% after adjusting for race, class type and ability scores. Even the strongest and most unusual fighters, with ability scores above 18, have surprisingly poor survival of about 30%. Orc ferocity increases mortality across all races and fighter types, with halflings again copping the pointy end of Gruumsh the Bastard’s falchion and incurring death rates of up 70%. This is further evidence that orcs are not CR 1/3 opponents, and suggests that GMs who want to field orcs as cannon fodder against their PCs should judge numbers carefully, or consider treating ferocity as a leader-type trait. It also suggests that – just on the numbers – Pathfinder is the most lethal of the D&D incarnations, especially when ability scores are restricted by point buy options. This will be tested in subsequent analyses.

In preparing an analysis of the effect of orc ferocity, I found I wasn’t able to reproduce the results of my previous post on different types of fighter and different races. The overall mortality in that post was 20%, but I kept getting values of 36%. Because I’m such a stunningly good programmer, I’d overwritten the program I used to produce those results, and it has taken me several days (interrupted by moving house) to dig up the original programs from Time Machine[1]. Checking through them I found a tiny error (three letters in one line of code out of 375[2]) which causes character hit points not to update after a round of combat – so that the only way the orc could win was to kill the PC on its first round of combat. That’s an interesting insight right there – 20% of the time the orc wins in the first round of combat!

So the true mortality rate in that analysis should have been 36%. I’m not going to redo the whole analysis (it’s late and I’m tired and I have a new analysis of ferocity to come), but I will put up the corrected table of mortality rates by race and fighter type, in Table 1.

Table 1: Mortality by race and fighter type (revised)

Race Fighter type
Strong Fast Tough
Human 20.4 36.7 35.1
Dwarf 18.8 43.6 36.2
Elf 30.7 52.2 38.7
Halfling 26.1 61.6 45.9

The general conclusion – that fast fighters are a disaster – is retained, but the effect is even more noticeable in elves and halflings, and high strength is even more important for these races than humans. Mortality rates in fast fighters are 1.8 times higher amongst humans, compared to over 2.5 times higher in halflings. Also, when the orc is not constrained from delivering a second blow, constitution becomes much less important than strength – being able to kill the orc first remains the most important skill.

Dwarves, who in this simulation have dropped power attack if they are strong fighters, benefit hugely from being strong rather than tough, presumably because they already have a constitution bonus.

So, the order of ability scores is: strength, constitution, dexterity. And I need to improve my programming!

fn1: which is awesome, btw.

fn2: which would probably be about 50, if I was any good at this stuff

After taking account of comments here and on the Paizo messageboards, I have adapted my simulation programs to allow for purposive attribute scores, feats and races, and re-analyzed the survival data for a smaller sample of more carefully designed fighters. In this second round of analyses Gruumsh the Bastard doesn’t acquit himself well, but neither do some of the PCs who went against him. This post reports on the updated analyses.

Update (3rd July 2012): In editing my code to incorporate some minor changes, I noticed that I didn’t actually pit 100,000 fighters against 100,000 randomly-generated orcs – I pitted 100,000 fighters against Gruumsh, who only has 6 hit points. Against a full range of Orcs one gets very different results – I will report on this today (3rd July 2012). This post has been edited to remove references to 100,000 randomly-generated orcs.

Introduction

Previous analyses of survival in Pathfinder have relied on randomly generated ability scores assigned in order, and have not incorporated feats, race, fighting styles or weapon types. In this post the analyses are updated to allow for a range of basic feats, four races, purposive rather than completely random assignment of ability scores, and three types of fighter: strong, fast and tough. Survival is compared against Gruumsh again, and results analyzed for insights into possible character creation decisions.

Methods

A sample of 100,000 randomly generated fighters were pitted in battle against Gruumsh, who is still not ferocious. The fighters were generated so as to fall into three types, defined by ability scores, armour and weapon types, and feat choices:

  • Strong fighters: strength was determined randomly from a uniform distribution between 13 and 18, and the fighters were equipped with scale mail and a two-handed sword. Human fighters had three feats: power attack, weapon focus and desperate battler. Humans placed their +2 ability score bonus in strength. Non-human fighters dropped power attack
  • Fast fighters: dexterity was determined randomly from a uniform distribution between 13 and 18, and the fighters were equipped with studded leather armour, a heavy wooden shield and a rapier. Human fighters had three feats: improved initiative, dodge and weapon finesse. Non-humans dropped weapon finesse, and humans put their +2 bonus into dexterity.
  • Tough fighters: constitution was determined randomly from a uniform distribution between 13 and 18, and the fighters were equipped with chain shirt, wooden shield and longsword. Human fighters had three feats: toughness, shield focus and weapon focus. Non-humans dropped toughness (because two of the races already had +2 constitution), and humans put their +2 bonus into constitution.

All other physical stats were generated with 3d6, but scores below 9 were reset to 9. Mental stats were generated using 3d6 in order, but nobody cares if their meat shield has read Shakespeare, so the details aren’t reported here. The hapless 100,000 were then thrown against Gruumsh, with the promise that anyone who survived would get to meet Salma Hayek. Needless to say, I lied: for unknown reasons, Hayek only dates bards. All fighters with power attack were assumed to be using it for every strike, and you would too if you met Gruumsh.

Results

After incorporating racial bonuses and feats, and assigning ability scores purposively rather than randomly, overall survival increased significantly: only 20% of the newly trained fighters died. However, variation in survival was significant and depended heavily on race and fighting style. Table 1 shows the mortality rates by race and fighter types.

Table 1: Mortality Rates by Race and Fighter Type
Race Strong Fast Tough
Human 17.1 26.5 0
Dwarf 11.1 21.8 1.1
Elven Ponce 27.3 46.9 16.4
Halfling Loser 21.2 45.3 8.3

From Table 1 it is clear that elves and halflings are not good fighters, and Dwarves are excellent in this particular role. The small difference in mortality between humans and dwarves is probably due to the reduced number of feats that dwarves have relative to humans. In fact, once feats and purposive ability score selection are included in character development, constitution becomes an extremely important score: 0% of fighters with constitution bonuses above 3 died. This is probably because CON bonuses of 3 or more guarantee a fighter cannot be killed in a single blow by an Orc (maximum damage 12) and the increased damage and hit stats of these fighters mean the orc will not survive to deliver a second blow. This is indisputably a good thing.

It is clear from table 1 that the least successful form of fighter is the fast fighter, and indeed some perverse results obtain. Figure 1 shows the mortality rate by dexterity score: mortality increases with increasing dexterity in this dataset. This is probably because higher dexterity scores are more likely in the “fast fighter” choice, and amongst halflings, both of which deliver less damage than other races and class types.

Figure 1: Mortality by dexterity score

A similar perverse result is visible with armour class. Figure 2 shows the relationship between mortality and armour class, which is positive.

Figure 2: Mortality by Armour Class

Again, it is likely that the highest armour class values are only achieved by halflings (who have size bonuses), and higher AC is associated with lower damage and attack values. Note that fast fighters have very high initiative values (up to +9!) but these don’t seem to say the battle: for fighters who start with a minimum of 8 hit points, starting the battle first is less important than being able to hit your opponent and do massive amounts of damage.

Conclusion

Dexterity is useless, and a fighting style based on light armour and fast weapons is a waste of time. As a result, weapon finesse is the ultimate wasted feat: it could have been used to get 3 more hit points, which for a first level fighter guarantees that one strike from an Orc will not be fatal. After incorporating feats, the best option for a first level fighter is to choose toughness, shield focus and weapon focus, and pour as many points as possible into constitution. 17 hit points, chain armour and a shield at first level are vastly more useful than a fancy fighting style and a leather skirt!

In yesterday’s analysis I made the mistake of assigning random HPs to the fighters, which is not the way that Pathfinder works: at first level in Pathfinder all PCs receive maximum hit points.Thus yesterday’s post is actually a fairly faithful representation of survival in D&D 3.5 rather than Pathfinder. Today I’ve brushed off a particularly irritable Gruumsh and set him to work against another million random fighters, this time with properly-adjusted hit points, in order to see what effect this rule has on the relative importance of stats.

The result is that the relative importance of the three ability scores doesn’t change, but overall survival probability has increased to 39%. For 15% of our army, that’s good news. The curves depicting overall survival rates don’t change overmuch though (Figure 1), they just start from a higher base.

Figure 1: Survival Rates by Ability Score, Maximum HPs at Level 1

Figure 2 shows how the survival probabilities have changed for constitution when fighters start with maximum HPs compared to random HPs.

Figure 2: Relationship Between Survival and Constitution for Fixed vs. Random HPs

The odds ratios change only a little, showing the same overall pattern (Table 1).

Variable OR P value Confidence Interval
Strength
  2 to 3

1

  4 to 5

0.24

0.001

0.11 to 0.53

  6 to 7

0.08

0

0.04 to 0.19

  8 to 9

0.04

0

0.02 to 0.08

  10 to 11

0.02

0

0.01 to 0.04

  12 to 13

0.01

0

0.01 to 0.03

  14 to 15

0.01

0

0 to 0.01

  16 to 17

0

0

0 to 0.01

  18 to 19

0

0

0 to 0.01

Dexterity
  2 to 3

1

  4 to 5

0.99

0.9

0.82 to 1.19

  6 to 7

0.86

0.1

0.72 to 1.03

  8 to 9

0.72

0

0.61 to 0.86

  10 to 11

0.6

0

0.5 to 0.72

  12 to 13

0.49

0

0.41 to 0.58

  14 to 15

0.39

0

0.33 to 0.47

  16 to 17

0.31

0

0.26 to 0.37

  18 to 19

0.23

0

0.19 to 0.28

Dexterity
  2 to 3

1

  4 to 5

0.95

0.56

0.78 to 1.14

  6 to 7

0.75

0.002

0.63 to 0.90

  8 to 9

0.56

0

0.47 to 0.67

  10 to 11

0.4

0

0.33 to 0.47

  12 to 13

0.31

0

0.26 to 0.37

  14 to 15

0.26

0

0.22 to 0.31

  16 to 17

0.24

0

0.2 to 0.29

  18 to 19

0.24

0

0.2 to 0.29

These are quite similar odds ratios to the situation with random Hit Points, except that the effect of higher constitution scores is a little greater (though still not as important as dexterity). Figure 3 shows the revised odds ratios for constitution.

Figure 3: Odds of mortality by constitution score, maximum hit points at first level

Conclusion

In Pathfinder, applying the proper rule at first level in which all fighters receive maximum hit points, overall survival increases from 25 to 38%, but constitution remains the least important ability score. The similarity in effect of dexterity and constitution in this revised simulation suggests that the role of feats will be crucial in determining which ability score to prioritize after strength, but the most important ability score remains strength. Probably over multiple levels, as random hit points begin to take their toll, constitution will be more important than dexterity, but we will test that later. The main finding is that although maximum hit points increase survival overall relative to D&D 3.5, they don’t change the overall importance of strength, and they do narrow the difference between dexterity and constitution.

I’ve decided to begin a long-term research project aimed at understanding the underlying epidemiology of Dungeons and Dragons. This research project will consist of a series of (hopefully) increasingly complex simulations of battles between D&D PCs and various nemeses, to answer some key questions in character development and perhaps also to investigate some key controversies in the game. Once I have developed my simulations I hope to extend the project to Exalted, and I might diversify beyond that too.

The simple weight of experience in D&D means that most people know, or feel they know, how D&D works and how the roll of the dice determines a PC’s fate. I have noticed that sometimes our intuitive understanding of these things can be wrong, and I’d like to investigate D&D in enough detail to understand how it works. I’ll write a separate post about some of the principles of the research project, but in this post I’ll present the first analysis.

Introduction

In this post a million battles are simulated between a million randomly-generated fighters and a single (unfortunate) Orc, Gruumsh The Bastard, who has 6 hit points and does 2d4+4 damage with his nasty falchion of fighter-crunching. Both Gruumsh and the million fighters were generated using Pathfinder rules as set out in the System Reference Document. These million battles were run in order to identify the effect of the three basic physical ability scores (Strength, Dexterity and Constitution) on survival for a standard fighter.

Methods Summary

Detailed methods are described at the end of the post. In essence, a million Pathfinder fighters were generated randomly and pitted against Gruumsh the Bastard in simulated battles. Fighter survival was analyzed using multiple logistic regression analysis by ability score. Survival probabilities by ability score are plotted in charts and summarized as Odds Ratios in the logistic regression analysis. No interactions or complex higher effects were considered. The distribution of hit points was summarized using a histogram, but doesn’t represent the true (practical) distribution of hit points for a fighter, since it includes fighters with unrealistically low constitution scores.

Results

Things didn’t go well for the million fighters. Overall survival was just 26%, with 256,584 lucky fighters making it to the end of their battle. The remaining 743,416 fighters were smashed to ribbons by Gruumsh and, in many cases, eaten. The median length of a battle was 4 rounds where the fighter survived, or 3 rounds if Gruumsh won. Figure 1 shows the probability of survival by ability score, and shows some stark differences in effect between ability scores.

Figure 1: Probability of Survival by Ability Score

It is clear from Figure 1 that strength is the key determinant of survival for a first level fighter. Only 0.4% of the weakest fighters survived, compared to 55% of the strongest. Constitution has barely any effect on survival, and dexterity is only important at the extreme ends of its range.

Table 1 summarizes the results of multiple logistic regression of mortality. In this table, the odds ratio of death is given after adjusting for the other two ability scores, so removes the confounding effect of high or low values in other relevant ability scores. All odds ratios are given relative to the lowest value of the corresponding ability score, so for example those with strength 18 – 19 have an odds ratio of mortality of 0.003 compared to those with a strength of 2-3.

Table 1: Multiple Logistic Regression of Death by Ability Score
Variable Odds Ratio 95% Confidence Interval P value
Strength
  2 to 3

Ref.

  4 to 5

0.21

0.06 – 0.66

0.008

  6 to 7

0.07

0.02 – 0.21

<0.001

  8 to 9

0.03

0.01 – 0.10

<0.001

  10 to 11

0.02

0.01 – 0.06

<0.001

  12 to 13

0.01

0 – 0.03

<0.001

  14 to 15

0.006

0 – 0.02

<0.001

  16 to 17

0.004

0 – 0.01

<0.001

  18 to 19

0.003

0 – 0.01

<0.001

Dexterity
  2 to 3

1

  4 to 5

0.87

0.69 – 1.10

0.236

  6 to 7

0.76

0.61 – 0.94

0.012

  8 to 9

0.65

0.53 – 0.81

<0.001

  10 to 11

0.54

0.44 – 0.67

<0.001

  12 to 13

0.45

0.36 – 0.55

<0.001

  14 to 15

0.37

0.3 – 0.45

<0.001

  16 to 17

0.3

0.24 – 0.37

<0.001

  18 to 19

0.23

0.18 – 0.28

<0.001

Constitution
  2 to 3

1

  4 to 5

0.9

0.73 – 1.11

0.307

  6 to 7

0.86

0.71 – 1.04

0.113

  8 to 9

0.82

0.68 – 0.99

0.044

  10 to 11

0.72

0.6 – 0.87

0.001

  12 to 13

0.63

0.52 – 0.76

<0.001

  14 to 15

0.55

0.45 – 0.66

<0.001

  16 to 17

0.48

0.4 – 0.58

<0.001

  18 to 19

0.41

0.34 – 0.49

<0.001

There is no difference statistically between a constitution score of 6-7 and a score of 2-3 – everyone with constitution scores in this range are purely at the mercy of the dice. In comparison, increasing strength from 3 to 4 reduces the odds of death by a factor of five, and fighters with a strength of 18 have an odds of mortality 300 times lower than fighters with a strength of three. Truly, fortune favours the strong.

Figure 2 shows the odds ratio of mortality for constitution with its 95% confidence intervals, as a graphical alternative to a portion of Table 1 (we promised Gruumsh we would describe his victory in pretty pictures).

Figure 2: Odds Ratio of Survival by Constitution Score

Figure 2 suggests that hit points are not as important to combat survival as the ability to smash your opponent into the dirt. Once the Toughness feat is incorporated into simulations, constitution is likely to become even less important, and should probably be treated as a dump stat by players. Given that choosing the Toughness feat is equivalent to making a large increase in constitution, but this increase in constitution gives a barely-statistically-significant reduction in mortality, it seems likely that this feat is not a very useful choice. If Gruumsh is willing, this will be investigated in subsequent analyses[1].

The distribution of strength ability scores under the 4d6 choose-the-best-three method is shown in Figure 3. This method shifts the scores significantly to the right: only 754 fighters had a strength of 3, compared to 16,141 who had a strength of 18. The mean strength was 12.24 and the median 12, a shift of three from a standard 3d6 distribution and a huge change to the extreme values.

Figure 3: Distribution of Strength Scores Under 4d6 choose-the-best-three

Nearly 5% of the sample had at least one physical score of 18; but this method is still not perfect, with only 3 of one million fighters having a score of 18 in all three physical attributes (one of these three, who also had an intelligence of 15 and a charisma of 16, was beaten to a bloody pulp by Gruumsh in just three rounds. His liver, apparently, was exquisite when grilled lightly and eaten on rye bread with a dark ale).

Figure 4 shows the distribution of hit points in this sample of 1 million fighters. This is not the distribution one would actually see in a sample of actual Pathfinder fighters, since in a real game most fighters will have non-negative constitution bonuses (unless their player has read this post, I suppose). This histogram shows an interesting effect, however: even when constitution is unrestricted, under a 4d6/choose-the-best-three system there is a heavy concentration of hit points in the range of 4 – 10. Median hit points in this sample were 6, and the average hit point total was 6.2: in fact, the hit point distribution looks remarkably close to a uniform distribution on the range 4 – 10!

Figure 4: Distribution of Hit Points

Survival was not strongly associated with hit point value: those with 1 hit point survived in 20% of battles, while those with 14 hit points survived in 50% of battles. This extra importance of hps relative to constitution is driven entirely by the extra die roll (the d10 for hps) which suggests that constitution would be of much greater importance if hit points were fixed at first level; equivalently, it may be that the roll of constitution is washed out by the random determination of hit points, and if so one can expect that constitution will be more important at later levels when the law of large numbers cancels out the random effect of dice rolls on survival. For the same reason strength will probably reduce in importance over levels, since its effect is not compounded with level as constitution is. This is an issue that will need to be investigated, although if survival probabilities are replicated at second level it’s unlikely we will have much of a sample size of high level PCs[2].

Conclusion

At first level, strength is far and away the most important ability score for fighters, and constitution is so insignificant as to be almost a dump stat. A fighter with strength of 18 has only 1/300th the odds of death of a fighter with strength 3 when fighting a single Orc. Overall survival rates were low even in the toughest fighters, and in the absence of feats it appears that Pathfinder is an extremely nasty environment for solo adventuring.

Future research will investigate the role of feats in enhancing survival, and their importance relative to ability scores. The results presented here are preliminary, but it appears that in min-maxing fighter PCs the wisest choice is to prioritize strength, then dexterity, then constitution. If one is developing a PC with the intention of long-term survival these findings may be reversed, but the experimental results have not yet been collated.

Finally, the results presented here suggest that the assignment of a 1/3 challenge rating (CR) to Orcs in Pathfinder may be unwarranted. Although data are not shown here, in the testing stage this simulation program was run on Goblins (also CR 1/3) and the fighter survival rate was much higher. It may be the case that Orcs are far more challenging than a CR of 1/3. It’s not clear how Pathfinder assign their CRs, but it seems natural to suppose that a creature with a more than 50% chance of defeating an average human fighter is more than CR 1. Are Pathfinder’s CRs accurate? In any case, basic advice to fighters in Pathfinder would be: hunt Goblins, not Orcs, they’re much lower risk for the same xps.

Methods

For this analysis the fighters were generated according to the following rules:

  • All ability scores were generated using 4d6 choose-the-best-three, rolled in order: This is not orthodox Pathfinder but enables simultaneous estimation of the probability distribution of ability scores under this commonly-used rule, and enables analysis of the effect of ability scores across their full range – not just in the high values that one would usually assign to a PC’s prime characteristics
  • No feats were assigned to the fighter: for this first analysis the effect of raw scores was the topic of analysis, so no special abilities were given to the fighters. These million meat-shields were cast into battle with only their raw talents at their disposal
  • All fighters had the same equipment: raising a levy of a million fighters takes only a minute in 64 bit R, but it’s clearly a costly imposition on the citizenry, so all fighters were assigned standard kit consisting of chain mail armour, a standard shield, and a longsword. If we can secure a sufficiently large research grant from Waterdeep, subsequent battles we will allow random variation in armour types in order to choose the best armour
  • Racial abilities were not tested: no racial ability score adjustments or size bonuses were tested. Only raw scores were used. In future battles, racial ability scores will be incorporated into the PCs. Anyway, who cares if a halfling lives or dies?

The results of all battles were summarized as two numbers: length of the combat in rounds, and whether or not the fighter lived or died (Gruumsh is a bastard, and his survival status is essentially irrelevant). Survival probability was plotted by ability score, and also analyzed using multiple logistic regression to assess the odds ratio of survival for any level of any ability after adjusting for all other abilities. Histograms of hit points and ability score (strength) were also obtained for reference purposes. The odds ratio of survival at different values of one score (constitution) was plotted with 95% confidence intervals.

No ethical approval was obtained for this study, and anyone with concerns about the ethics of the study can raise the issue with Gruumsh. Informed consent was not obtained from any subjects (though Gruumsh seemed pretty eager to participate, and said “smash human!” many times, so could probably be said to have given active consent). No medical care or counselling was offered to survivors of the battles, and no reward was offered. The lucky minority who survived probably went off to start a farm or something, but we don’t know because follow-up to assess general physical health or emotional needs was not offered. Experience points were not distributed to the victors, because if we did Gruumsh would have gained enough levels to take over the world and no one wants that. Gruumsh was allowed to feast on the remains of his vanquished foes, because culturally sensitive research techniques are very highly prized at the Faustusnotes Military Academy. All simulations were conducted in R version 2.15.0, and all analyses were carried out in Stata/MP 12 because R sucks for things like making simple tables. The analyst was not blinded to the participants in the study, but if you think he had any interest in scanning a million records of a .csv file looking for fighters to favour, you’re an over-optimistic fool. This study was also not registered with CONSORT, but it’s unlikely that it would get published in any public health journal, so there was no need, really, was there?

fn1: Actually, Gruumsh is unlikely to get a choice. We’ll just roll up the fighters and send them in his direction.

fn2: Actually, if we run a series of level-by-level simulations we could test whether the probability distributions of levels given in the D&D DMG are correct, and come up with empirical estimates of the true proportion of the population who are higher level!

A commenter at a Genesys community group online has made the following comment about my criticisms of the role Brawn plays in the Genesys combat rules:

One rule that stands out to me relates to party composition in combat and I haven’t seen it mentioned here. If an ally is engaged with the target of a ranged attack (magical or mundane) the attack must upgrade the difficulty once and any despair causes the attack to instead strike the ally. This, combined with setback from the cover rules causes allied melee fighters to either risk causing their ranged allies to miss, hit them instead, or, as is most often the case, choose to shoot something else.

This is true, but I think it doesn’t fully encapsulate how much of a difference brawn makes even to situations where we choose party composition. So let’s consider two scenarios involving combatants maximized for combat and melee.

Introducing the combatants

First let’s introduce our melee combatant, Gruumsh the Bastard, pulled out of retirement from the pathfinder epidemiology project[1] to do his duty as an experimental subject in our battlegrounds. Gruumsh has a brawn of 4, all other attributes at 2, 2 skill ranks in melee, 1 rank in ranged, no stealth (who needs that?!), a greatsword, a bow and chainmail armour. He thus has a melee defense of 1, 14 wounds, soak 6, does 8 damage when he hits you, and 7 damage if he decides to shoot you. For the purpose of this experiment (to retain fairness) Gruumsh has been dragged from Pathfinder to the Realms of Terrinoth in a human form.

Ranged (haha) against Gruumsh the Bastard is Elegant Eddie. Elegant Eddie has an agility of 4, all other attributes at 2, 2 skill ranks in ranged, 1 rank in melee, 2 ranks in stealth, a sword, a longbow and chainmail armour. He thus has a defense of 1 when in melee, 12 wounds, soak 4, does 8 damage when he shoots you and 5 damage when he stabs you. Eddie is also a human, though a miserable example of his kind as far as Gruumsh is concerned.

Now let’s try two scenarios.

Scenario 1: Firing into melee

We suppose first that Gruumsh has an ally like Eddie, who is nameless. He is attacking Eddie’s ally, who is like Gruumsh, in melee. We don’t care how this melee turns out in detail, but what we want to investigate is the consequence of Gruumsh being engaged while his nameless ally fires into melee. The specific rules of this state that we upgrade the difficulty of the shot by 1, so let’s put Gruumsh’s ally at short range and have him thus use a single red dice for difficulty. If he rolls a despair then he will hit Gruumsh. There is a 1/12 chance of a despair on the ally’s dice pool, so about an 8% chance he’ll hit Gruumsh. The maximum damage he can do in this situation with a truly ridiculous roll is 15 damage, of which Gruumsh can absorb 6, taking 9. A more realistic roll would see the attack do 11 damage, of which Gruumsh takes 5. So realistically this can happen 3 times before Gruumsh goes down. There is a scenario in which Gruumsh’s ally rolls despairs and triumphs, and thus does a critical on Gruumsh, but the chance of this is very low – my calculations put it at about 1% – and any GM who ruled in the extraordinary case of rolling 2 triumphs and 1 despair that the triumphs and the despair don’t cancel would likely not survive the session.

It’s worth noting in this case that the final probability of missing the enemy is similar with or without the upgrade, so if Gruumsh doesn’t engage this enemy and leaves it to his ally to shoot, the party is not significantly improving the chances of the ally doing damage on the enemy – and what is going to happen if Gruumsh doesn’t engage? Which brings us to scenario 2: Gruumsh and Eddie at range.

Scenario 2: A ranged stand off

Let’s suppose that Elegant Eddie and Gruumsh the bastard face off at medium range. Here the difficulty for Elegant Eddie to hit Gruumsh is two purple dice. Let’s suppose they shoot each other, so Gruumsh is not using his best skill. In this case if Elegant Eddie gets one success against Gruumsh he does 9 points of damage, which is 3 net; if Gruumsh gets one success on Elegant Eddie he does 8 points of damage, which is 4 net. For Elegant Eddie to do more damage than Gruumsh in this ranged stand off he needs 2 more successes than Gruumsh! Now each ability die is equivalent on average to 0.625 successes, and each skill die 0.83 successes, so this deficit is the equivalent of Elegant Eddie having two less ability dice and one less skill die – so basically the equivalent of Gruumsh’s agility and skill, but for the slightly elevated chance of a critical[2]. Also note that if they’re dealing approximately the same damage to each other after soak, Gruumsh will kill Elegant Eddie first, because Gruumsh has more wounds. So unless Elegant Eddie gets lucky with criticals there is a chance that he will lose this battle even though he is fighting it with his best ability and Gruumsh the bastard is not.

Now let’s suppose that instead of shooting Gruumsh decides to charge Elegant Eddie. He needs to close from meidum range to engaged, which will take him two manoeuvres: one from medium to short, one from short to engaged. This means that he can spend two strain and gets one attack against Elegant Eddie. Note that even though Elegant Eddie has better agility he doesn’t have better initiative chances, so it’s possible that he’ll never get a chance to shoot Gruumsh, but just in case, let’s assume he does. The maximum damage he can do is 16, of which Gruumsh will take 10, so Gruumsh is guaranteed to reach melee this round. There is a small chance that Elegant Eddie will get a critical, in which case there are a couple of criticals he can roll up (11-20, 41-45, 71-75, 81-85, and 96 – 105 if we are going to be generous to Eddie) that could stop Gruumsh from closing range. My estimation of probabilities puts the chance of this chain of events happening at less than 3%. So there is a 97% chance that Gruumsh is going to close range and get an attack in one round.

The maximum damage Gruumsh can do is the same as Elegant Eddie: 16. But Elegant Eddie has 4 soak and 12 wounds, so Gruumsh can knock him out in one round. The chance of this is low obviously, but note that the minimum damage Gruumsh can do on a successful hit is 9, which translates to 5 for Elegant Eddie, so there is almost zero chance that Elegant Eddie is going to survive two hits – and next round he’s going to need to use his free manoeuvre (assuming he gets one) to get his sword out. Once his sword is out there is actually a chance he’ll do zero damage against Gruumsh even on a successful hit!

A note on cover

Let us suppose that Gruumsh the Bastard wins the initiative and sees that Elegant Eddie has a ranged weapon. Suppose that there is some cover at short range that gives him two defense. He could use his free manoeuvre to get there, dive into cover, then next turn use another free manoeuvre to close to engaged, thus saving two strain. Is this worth it? Each point of defense has a 1/3 chance of reducing Elegant Eddie’s dice pool result by one success, so the two dice in total could reduce the dice pool by two successes at most, some of the time. But Gruumsh the Bastard has two extra points of soak than Elegant Eddie, so this cover is less effective than his brawn advantage in protecting him. The rule book says that two cover dice is equivalent to a trench or blockhouse. Gruumsh’s brawn advantage is better than putting him in a pillbox! If Gruumsh opts to run to cover he would be offering his opponent a chance at a shot at reduced difficulty, with almost no benefit, even if that cover were a blockhouse! Unless Gruumsh is already down to his last two strain, the simple fact is that there is no benefit to him in pausing – he should just rush to melee. Note that if the cover were at medium range and the battle started at long range, he would probably be better off waiting for Elegant Eddie to shoot, rather than running to cover, because the benefit to him of gaining the two cover dice does not out weigh the benefit to Elegant Eddie of the range improvement, given his brawn. He is better off just pausing his run, standing at long range, waiting for Elegant Eddie to shoot him, and then closing to cover. And if Elegant Eddie uses his free manoeuvre to maintain the range so that they have to turn this into a shooting match, Gruumsh’s brawn will neutralize Eddie’s extra skill anyway!

Conclusion

Truly Gruumsh is a bastard. His brawn acts as a dampener on ranged attacks, so that PCs who have chosen to maximize this skill are effectively no better at it than Gruumsh himself (and Gruumsh obviously disdains such petty strategies). Although it is true that firing into a combat in which Gruumsh is engaged slightly increases the risk of harm to him, this risk is small and not worth foregoing Gruumsh’s rush into combat. Worse still, if Gruumsh and a ranged fighter enter an encounter at medium range there is almost no chance that the ranged fighter will survive, even though the engagement has started in a way that should heavily favour the ranged combatant. There is no reason for Gruumsh to seek cover if he wins the initiative, since his brawn effectively acts as if he were hiding in a bunkhouse anyway. None of this is an issue if brawn does not affect soak, and note that things become even more catastrophically difficult for Gruumsh if agility determines combat skill – then Gruumsh would be better off with 3 brawn and 3 agility, and all his calculations would change. Just as in my original experiments in Pathfinder, being able to kill someone quickly outweighs fancy considerations of style, and the doubling up of brawn to both defense and offense means that brawn-focused characters are more dangerous than better-armed opponents even in ranged combat!

Some arguments in the online community where this debate unfolded suggested that Genesys was developed for ranged combat, because it was developed for Star Wars, where blasters are the core weapon. First, this isn’t true – the Star Wars system was developed from Warhammer 3rd Edition, which was developed for a world of Grim Fantasy. Secondly, it’s also wrong. This analysis shows that the system clearly disadvantages ranged fighters heavily.

One small limitation of my analysis here is that I have not considered the cost of completely missing (or the benefits of being completely missed) in scenario 2. This might slightly readjust the balance of risks, but is complicated to calculate for Genesys dice pools. But overall I don’t think that nuance significantly changes the basic finding, which is that brawn serves to neutralize ranged attacks through soak to such a degree that it completely distorts the balance of combat. Brawn should not be applied to soak, or if it is, melee attacks should all be agility based.


fn1: Incidentally, it’s interesting to compare the generally positive response of the Pathfinder community to my rules suggestions there back in 2015, with the negativity and criticism of the Genesys community.

fn2: I am using this approximation because calculating precise probabilities for dice pools in Genesys is tough and I can’t be bothered writing the R code to do it.

Character creation decisions

In the Genesys system brawn determines your wound threshold, the damage your melee weapon does, how much you can carry, whether you can use a cumbersome weapon, your resilience skill, and how much damage you take. Its role in determining wound threshold and soak means it is double-counted in survival: if my brawn is 1 higher than your brawn I start with 1 more wound than you and take 1 less every time someone hits me. Its use in determining weapon damage means it is also double-counted in combat: being used as the base attribute for the skill, it determines how many successes you get (and thus the damage); and this is added on again because brawn also determines the damage of the weapon.

I think this makes brawn overpowered, and it certainly means that no combat-focused character need care about any other attribute. This is particularly true if one uses the rules as written for determining combat difficulties, since the difficulty of hitting someone is not affected by any attribute of theirs. So to be a good fighter you just need a good brawn. Every other character type needs at least two good attributes (e.g. wizards, who usually rely on a different attribute for spell casting vs. strain), but a fighter type can survive with just brawn.

This level of overpowered attribute is also seen in D&D 5th Edition, where dexterity determines how hard you are to hit, your attack bonus, and your damage. Strength becomes irrelevant to a fighter in D&D, and perversely if you really want to a lot of damage you’re better off being a rogue. The role of a fighter in D&D 5 is to give the rogue a chance to flank their opponent (also a terrible rule), not to deal out damage. This is perverse and frustrating, and one of the first changes anyone who plays D&D should make is to revert to strength for weapon damage (at least!)

D&D and Genesys aren’t alone in having over-powered attributes, which is a problem going back to the 1980s and Cyberpunk, which has a suite of attributes of which only two matter. These kinds of rules can be very frustrating because whenever a combat comes up they leave all the other players just watching as a single player does everything for the whole group. Whether it’s realistic or not that a certain attribute entirely determines who is best at something, it’s no fun in a game, and to my mind (and that of most players I’ve ever gamed with) good character design should require that the PC needs two good attributes and can afford to get away with one bad one. It’s not like this in Genesys at the moment.

Brawn and agility in actual combat

Brawn vs Agility

The focus on Brawn in Genesys is also not really realistic, and in particular the soak thing is quite weird. I’ve been kickboxing for years and I know what it’s like to be punched and kicked in the head (and the ribs and the leg and …), and in general one’s ability to resist damage is primarily a quirk of fate. Obviously size determines how much damage you can take (your wound threshold) but most people aren’t especially good at resisting damage. It’s true you see a good boxer taking body shots and wearing them but this isn’t just about brawn – it’s also experience, and most of all timing to turn the body away and tense the muscles at the right time. The classic modern example of this is the much-maligned calf kick, which is becoming very popular in mixed martial arts precisely because no human body seems to be able to ignore it. Whether you absorb that damage or suffer it depends entirely on whether you can shift your leg in time – which is also the entire point of the leg check, which exists to protect your leg (brawn) by absorbing the blow on a bone (using agility to put the bone in the way of the soft part).

The model of the quirky damage-resister in modern fighting is Rodtang (pictured above left), who can actually wear punches, shake his head and keep fighting. He was what the pundits would call an iron chin, but this is highly unusual. Almost all fighters avoid being knocked out by not getting hit, or by rolling with the punches. Obviously much bigger men are harder to knock out for smaller men, but generally, within broad ranges of size, most people can’t resist damage just by being hard. People who think they have this ability are, usually, people who’ve never been really seriously punched.

So, I think Genesys needs to be reformed to reduce the role of Brawn. I think this requires:

  • Make agility the primary attribute for melee attacks
  • Eliminate soak, and either increase armour soak ratings to compensate, or slightly reduce weapon damage
  • Use my reformed combat rules to ensure agility can affect how hard you are to hit, but give brawn some role
  • Introduce some special talents to enable fighters to choose to focus on brawn as a combat component if they want

With this reform, brawn still affects wound threshold and weapon damage, but does not double-count in either. It also means that a good fighter needs to have two strong attributes (at least), and that other types of fighters (who are fast, or use talents) can also hold their own on the battlefield.

Iron chin talent tree

Here I propose a few talents for players who want to develop a PC who fights entirely with brawn. They assume my revised combat rules, which a) assume that skills affect how hard you are to hit and b) ensure that you take a point of strain whenever your armour and soak fully absorbs damage.

  • Hardened fighter (Tier 1): For every rank of hardened fighter, increase your soak by 1
  • Shrug it off (Tier 2): (Requires hardened fighter) Whenever you suffer a rank 1 critical, make a resilience check against your current wounded state. If you succeed, the critical does not affect you
  • Taste for blood (Tier 3): (Requires shrug it off) Once you have been hit once in combat, you no longer suffer strain if your armour absorbs all the damage from future hits
  • Physical bravery (Tier 4): (Requires taste for blood) When you reach your wound threshold, make a resilience check against your current wounded state. If you succeed, you do not go unconscious: keep fighting until someone hits you again (when you need to make this check again)
  • Stalwart (Tier 5): (Requires physical bravery) As shrug it off, but you make the resilience check for any critical injury, against the critical rating, upgraded once if you are already critically injured.

These are just example talents, I’m not sure how unbalancing they might be in combat (and Shrug it off might be underpowered). In my campaign orcs already have the physical bravery talent, and it’s a lot of fun.

Choosing your melee and soak attributes

Another idea that could be considered, though I haven’t put much thought into it, is to allow PCs to choose the attribute they use for soak at the beginning of the campaign. Perhaps the list could be brawn, agility, willpower or presence. Thus you could have a wizard who is hard to hurt because of their sheer force of will, or a bard who refuses to show their pain to an audience.

It’s also possible that weapons could be reformed so different weapons use different attributes, or the brawl, light and heavy melee skills are reformed to use agility, cunning and brawn respectively (in general I think cunning is not a very useful attribute in Genesys). This makes a clear distinction between fast fighters, smart fighters, and tough fighters, something I think most players want to see in a nuanced rule system but which I have shown before often falls apart in practice.

In any case, the key thing here, whatever method one uses, is to reduce the oversized influence of brawn on combat effectiveness, and force fighter characters to be less one dimensional, as well as give other PCs more options and effectiveness in combat. I am not sure if I am going to introduce this reform to my system – at the moment we have only one heavy fighter anyway, and we’ve just gone through a round of rules changes so another set at this point might be pushing the limits of my players’ patience – but I hope the Genesys creators will consider this issue in future iterations of the game.

Addendum: Overpowered stats and role diversity

Some people on the Genesys facebook group have made the point that combat is about more than striking and running, and other characters with other attributes can contribute by doing other things. This is true, but it’s not enough for two reasons. First of all, every critique of every system always gets this response that “role-playing is about creativity, you can find ways to do things that don’t involve violence,” but this is not really fair. First of all, over 30 years of gaming I have never played in any group that didn’t have a heavy focus on violence, and secondly if creativity is so important, why do we have rules at all? We have rules because they’re an important support for our creativity, and the nature of rules changes the way our creativity works. This “oh just be creative in combat” response is always frustrating!

Secondly, however, this response misses an important point about overpowered stats. If one stat is overpowered, then PCs whose primary role depends on that stat will have more choices to be creative in character development than others. Rather than being one-dimensional tanks, brawn-based fighters have more choices to flesh out their PCs. This is because they can excel at their main role with just one attribute, while other PCs need two. Compare, for example, a wizard character that uses presence to cast spells. They will need brawn to stay alive in combat and willpower for their strain threshold. Even if they decide to be fragile, in order to be good at their role they need two attributes. This means that they have less attributes to throw around in secondary character development. It is likely, therefore, that such a PC will choose social skills based on presence – so most such wizards will be leaders or seducers, rather than say kids who ran with gangs (cunning) or acrobats (agility). In contrast, a PC that is primarily a fighter needs only one attribute to be good at what they primarily do, so they have more attributes to throw around. So a fighter-type character can choose to be a leader (presence), a stoic grave-robber whose seen things you wouldn’t believe (willpower), someone who grew up on the streets before they joined the army (cunning) and so on. This PC, rather than being more one-dimensional than those others, will be more flexible! He or she will be able to fight like a monster and be the party’s go-to character for negotiation and perception (for example), while other PCs cannot fit the same diversity of roles because they have sunk all their attributes onto their main role.

A really good example of this problem is the D&D 5E rogue, who is great in combat but also a good archer and has a wide array of super useful crime-style skills. Much of a D&D 5E adventure involves the other PCs waiting for the rogue: they send the rogue ahead to scout the enemy, they set the combat up to ensure the rogue can flank, after the combat they wait for the rogue to check the chest for traps, then the rogue unlocks the chest, and so on. Far from being one-dimensional, the rogue is a more diverse character than any of the others.

So, for a system to fairly encourage role-sharing and ensure that all PCs can contribute to combat, paradoxically, it needs to ensure that the primary fighter characters depend on the same number of attributes to be good at their role as every other PC. Otherwise, rather than only enjoying the combat and being a one-dimensional brawler, they will be the only PC that can enjoy combat and contribute to everything else. And that makes other players bored and frustrated, which is not the point of these games!

Over the past few years I’ve looked at a lot of the probabilistic and statistical aspects of specific game designs, from the Japanese game Double Cross 3 to Pathfinder, including comparing different systems and providing some general notes on dice pools. I’ve also played various amounts of World of Darkness, Iron Kingdoms, D&D, Warhammer 2 and 3, and some Japanese systems, that all have quite diverse systems. Given this experience and the analytical background, it seems reasonable to start drawing it all together to ponder what make for some good basic principles of RPG system design. I don’t mean here the ineffable substance of a good RPG, rather I mean the kind of basic mechanical details that can make or break a system for long term play, regardless of its world-building, background and design. For example, I think Shadowrun might be broken in its basic form, to the extent that people who try playing it for any length of time get exasperated, and this might explain why every gaming company that handles Shadowrun seems to go bust.

So, here is a brief list of what I think might be some important principles to use in the development of games. Of course they’re all just my opinion, which comes with the usual disclaimers. Have at ’em in comments if you think any are egregiously bad!

  • Dice pools are fun: everyone likes rolling handfuls of dice, and the weighty feeling of a big hand of dice before a big attack really makes you feel viscerally there, in comparison to a single d20
  • Big or complex dice pools suck: Big dice pools can really slow down the construction and counting parts of rolling a skill check, but on top of this they are basically constructing a binomial distribution, and with more than a couple of trials (dice) in a binomial distribution, it’s extremely hard to get very low numbers of successes. So large and complex dice pools need to be limited, or reserved for super-special attacks
  • Attacks should use a single roll: Having opposed skill checks in combat means doubling the number of rolls, and really slows things down. Having cast around through a lot of different systems, I have to say that the saving throw mechanism of D&D is really effective, because it reduces the attack to one roll and it makes the PC the agent of their own demise or survival when someone attacks them. On the other hand, rolling to hit and then rolling to damage seems terribly inefficient
  • Where possible, the PC should be the agent of the check: that is, if there is a choice in the rules where the GM could roll to affect the PC, or the PC could roll to avoid being affected by the GM, the latter choice is better. See my note above on saving throws.
  • Efficiency of resolution is important: the less rolls, counts and general faffs, the better.
  • Probability distributions should be intuitively understandable: or at least, explainable in the rules – and estimates of the effect of changes to the dice system (bonuses, extra dice, etc.) should be explained so GMs can understand how to handle challenges
  • Skill should affect defense: so many games (D&D and World of Darkness as immediate examples) don’t incorporate the PC’s skills into defense at all, or much. In both games, armour and attributes are the entire determinant of your defense. This is just silly. Attributes alone should not determine how well you survive.
  • Attributes should never be double-counted: In Warhammer 3, Toughness determines your hit points and acts as soak in combat; in D&D strength determines your chance to hit and is then added again to your damage. In both cases this means that your attribute is being given twice the weight in a crucial challenge. This should be avoided.
  • Fatigue and resource-management add risk and fun: Fighting and running and being blown up are exhausting, and so is casting spells; a mechanism for incorporating this into how your PCs decide what to do next is important. Most games have this (even D&D’s spells-per-day mechanism is basically a fatigue mechanism, if a somewhat blunt one), and I would argue that where possible adding elements of randomness to this mechanism really makes the player’s task interesting. But …
  • Resource-management should not be time-consuming: this is a big problem of Warhammer 3, which combined fatigue management with cool-downs and power points. Too much!
  • The PCs should have a game-breaker: we’re heroes after all. Edge, Fate, Feat points, Fortune … many games have this property, and it’s really useful both as a circuit-breaker for times when the GM completely miscalculates adversaries, and as ways for players to escape from disastrous scenarios, and to add heroism to the game
  • Skills should be broad, simple and accessible: The path of Maximum Skill Diversity laid out in Pathfinder is not a good path. The simplification and generalization of skills laid out in Warhammer 3 is the way to go.
  • Wizards should have utility magic: the 13th Age/D&D 4th Edition idea of reducing magic to just another kind of weapon is really a fun-killer. The AD&D list of millions of useless spells that you one day find yourself really needing is a much more fun and enjoyable way of being a wizard. It’s telling that D&D 5th Edition has resurrected this.
  • Character classes and levels are fun: I don’t know why, they just are. Anyone who claims they didn’t like the beautifully drawn and elaborate career section of Warhammer 2 is lying. Sure, diversity should be possible within careers but there should be distinction between careers and clarity in their separate roles (something that, for example, doesn’t seem to actually be a strong point of Iron Kingdoms despite its huge range of careers). At higher levels characters should really rock in the main roles of their class
  • Bards suck: they just do. Social skills should be important in games, but elevating them to a central class trait really should be reserved for very specialized game settings. Bards suck in Rolemaster, they suck in D&D, they suck in 13th Age and they suck in Iron Kingdoms. Don’t play a bard.
  • Magic should be powerful: John Micksen, my current World of Darkness Mage, is awesome, but mainly because he is cleverly combining 4 ranks in life magic and 3 ranks in fate magic with some serious physical prowess and a +5 magic sword (Excalibur, in fact!) to get his 21 dice of awesome. Most of the spells in the Mage book suck, and if you made the mistake of playing a mage who specializes in Prime and Spirit… well, basically you’re doomed, and everyone is going to think you’re a loser. Mages should be powerful and their powers – which in every system seem to come with risk for no apparent justifiable reason – should be something that others are afraid of. You’ll never meet a World of Darkness group who yell “get the mage first!” What’s the point of that?
  • Death spirals are important: PCs should be aware that the longer they are in a battle, the more risky it gets for them. They should be afraid of every wound, and should be willing to consider withdrawal from combat rather than continuing, before the TPK. Death spirals are an excellent way to achieve this combination of caution and ultra-violence. Getting hit hurts, and players should be subjected to a mechanism that reminds them of that.

I don’t know if any game can live up to all these principles, though it’s possible a simplified version of Shadowrun might cut it, and some aspects of the simplified Warhammer 3 I used recently came close (though ultimately that system remains irretrievably broken). Is there any system that meets all of these principles?