Here are a couple of examples of “actions” based on the skill-based d20 system I developed a while ago, combined with the Actions framework discussed yesterday. One is a spell, one a “supernatural ability” and one a “mundane” (and hideous) special ability. The Cost line in each description gives the attribute against which damage is done if the action fails. The cost is always 1 wound. In my conception of magic, arcane magic incurs a physical cost (it is exhausting) while divine magic incurs a mental cost (it drives you a little bit.. irrational and loopy). So failed arcane spells incur a wound against strength, while failed divine spells incur a wound against intelligence. In this system, a critical is achieved by a roll of a 20, at which point 2d10 are re-rolled and added to the previous roll to get a new total. On rolling a critical, all maximum effects (damage, rounds of duration of effect, etc.) are increased by some amount.

Grendel’s Demise

Type: Spell

Level: 7

Cost: Strength

Conditions: Must have one hand free and be unencumbered, not wearing metal armour. Target must be within sight, and have at least one arm or other limb.

Skill check: Intelligence (Offense) vs. Target Strength (Defense)

Critical: Yes (Double)

Effect: This spell attempts to tear off the target’s arm. It does maximum damage 7, and the target is stunned for one round plus one round per point of success (maximum 7, double on a critical). The target is also bleeding (1 wound/rd) until healing is administered. The target loses all use of one arm, either temporarily (due to massive injury) or permanently (due to amputation) at the GM’s discretion.

Hideous death

Type: attack, reaction

Level: 1

Cost: Charisma

Conditions: Attacker must be visible to the targets of the action, who must be allies of the target. Target must have been reduced to 0 hps in this round, by the PC or one of his/her allies.

Skill check: Charisma (Offense) vs. Charisma (Defense)

Effect: The character turns an opponent’s death into a lurid display of horror and gore. Any ally of the dying enemy who witnesses his/her/its death is shaken for 1 rd plus 1 rd/point of success. The target experiences a -2 penalty on all actions and will attempt to avoid combat with the character if possible. If the target is already shaken due to witnessing a hideous death in this engagement by this character, they move from shaken to terrified, and will immediately attempt to flee the battle.

If this action is being used on an enemy the character did not kill, apply a -2 penalty to the skill check.

The GM may choose to allow the player to describe the type of hideous death for an attempt at a bonus on the skill check. This is strongly advised! Note that failure to successfully terrify the target merely makes the PC look like a bloodthirsty maniac (charisma damage).

Infernal Essence

Type: Ability

Level: 1

Cost: None

Skill check: Wisdom (Use) vs. DC 20

Effect: The PC conjures an infernal essence to enhance their weapon or armour, giving a +1 to maximum damage or damage reduction for 1 min + 1 min/pt of success (maximum=character level). This is an infernal effect, so can be dispelled by demon-binding or abjuration effects, but not by magic-dispelling effects. It is usually visible as a faint glow and/or feeling of discomfort or unpleasantness surrounding the PC.

Higher-level versions of this effect are possible, and give an effect equal to the level of the action.

Spells are cast as a skill, with the base difficulty for partial success given by

DC = 15 + Spell level + Effect Modifications

Usually these effect modifications represent a decision to increase the number of targets beyond the basic amount allowed by the spell level; or an attempt to increase duration.

Partial failure occurs if the character rolls below [DC-lvl].

Whether or not a spell is successful on partial failure, partial success or complete success depends on the basic type of spell effect.

Spell Level is unlimited from 0 up and increases or decreases according to the basic type of spell effect, the duration, the range and the area. There are three main types of effects:

•    Fixed wondrous effects, such as light, confusion, etc. which are either automatic, or affect enemy creatures in an opposed skill check (Spellcraft vs. Will/Presence etc). Duration of these spells is usually determined by the amount by which the target fails the opposed skill check.

•    Variable benefit/damage effects, which manifest as bonuses to a skill or stat, or as damage done/healing. These are characterized by a maximum amount they can attain, and are variable up to the maximum amount. Duration is usually fixed at 1 round per level of the caster.

•    Fixed benefit/damage effects, which manifest in the same way as variable effects, but always to a fixed amount. This means that they can work on partial failure, but their difficulty is usually higher. Also, the duration of these spells depends on the degree of success.

Essentially, a spell can have a variable effect for a fixed duration, or a fixed effect for a variable duration.

Table 1 characterises the way in which the three basic types of effects determine success.

Unit of duration: Every spell has a unit of duration determined as part of its creation. This is usually 1 round, but can be in minutes, hours, days, or simply be permanent. For all units of duration except permanent, the spell lasts a period of time equal to some multiplier of the units of duration.

Table 1: Success determination by basic spell type

Spell Effect type

Basic rule

Effect on partial failure

Effect on success

Wondrous effects, no target

Spell always works on partial

failure or better. Degree of success determines duration

Spell works; fatigue; spell

lasts 1 unit of duration

Spell works; no fatigue; spell

lasts a number of duration units equal to [skill roll-DC]+1

Wondrous effects, hostile


Spell effect only takes hold if

the caster can beat the target on an opposed skill check

Spell works; fatigue; opposed

skill check DC=die roll. Duration 1 unit of duration per point of failure, +1

Spell works; no fatigue;

opposed skill check DC=die roll. Duration 1 unit of duration per point of

failure, +1

Variable benefit effects

Spell only works on partial or

complete success; benefit varies up to some maximum

Spell does not work; fatigue

Spell works; no fatigue;

benefit is given by [spell roll-DC] up to the maximum

Variable damage effects

Spell works on partial failure;

damage determined by opposed skill check

Spell works; fatigue; opposed

skill check DC = die roll. Effect = 1+1/point of failure up to the maximum

Spell works; no fatigue;

opposed skill check DC = die roll. Effect = 1+1/point of failure up to the maximum

Fixed benefit effects

Spell works on partial failure;

benefit is always fixed, but the duration depends on the spell roll

Spell works; fatigue; full

effect; spell lasts 1 unit of duration

Spell works; no fatigue; spell

lasts a number of duration units equal to [skill roll-DC]+1

Fixed damage effects (curses,


Spell works on partial failure;

benefit is always fixed, but the duration depends on the spell roll

Spell works; fatigue; full

damage; spell lasts 1 unit of duration

Spell works; no fatigue; spell

lasts a number of duration units equal to [skill roll-DC]+1

For the purposes of simple gameplay, we note that spell effects which do stat or skill damage are treated in the same way under these rules as spells that do physical damage. However, this implies that spells which do physical damage will not be permanent. For the purposes of this one type of spell, we assume that the damage effect is permanent. Usually this would require that the spell be considerably higher level than is strictly reasonable, so we waive this consideration for healing and damage spells (see table 3 regarding duration).

Spell Difficulty

Spell difficulty depends on which of the three basic effect types the spell employs.

Variable benefit/damage: Level = [Max effect]/2

Fixed effect/damage: Level = effect

Table 2 shows the wondrous effects with their base level.

Table 2: wondrous effects with their levels





Daze, knockdown


Stun, deafness, rage[1],

courage1, telekinesis, fascinate,


charm, comprehend/confuse

language, camouflage/hidden, change size, Sleep[2],


Blindness, forget, Disguise,

alien environment, Pain[2], slow, freedom of movement


Paralysis, fear, invisible,


clairaudience, Scrying, minor

spell effect[3], haste


confusion, Change form

(mundane), Teleport (minor, not through obstacles),


Telepathy, improved

invisibility, medium spell effect,


Insanity, major injury (removes

most of a creature’s fighting ability without death)


Major spell effect, Domination,




Change form (supernatural),

Disintegration, Teleport, Extreme spell effect,


Imprisonment/banishment, change





Time Stop




Note that conjuration can be estimated as a DC given by the level of the creature, with a small addition for the conjuration itself (perhaps 1). These levels have been designed to roughly match twice the levels of spells in D&D 3rd edition, with some modifications made possible by doubling the level range. There is no particular reason why the level range should be fixed at 16.

Combining spell effects should use their sum, minus an amount which increases with the levels and numbers of combinations. So for example, daze and knockdown should be level 2; while daze and pain and blindness should be level 6.


The base unit of duration for all spells is rounds. Spells which do physical damage or which heal people are considered to have permanent base unit of duration, as are spells of abjuration. This is subject to DM discretion. Spells with base duration permanent cannot have their duration reduced.

The base unit of duration can be extended by increasing the level of the spell, as shown in table 3.

Table 3:

style=”mso-spacerun: yes”> Duration of effect


Level change











Area of effect

Area of effect depends on the domain of the spell. The effects by domain are shown in table 4.

Table 4: Area of



Area effect


1 creature


1 creature


1 creature


3m area

The area of effect can be increased by 1 of these base units by increasing the spell DC by 1 freely at time of casting. Evocation can be reduced in size to “beam” (essentially 1 creature) at a DC improvement of 1.


The range also depends on domain, as shown in table 5.

Longer ranges can be obtained by increasing DC by +1 through the categories:

Self / Touch / 10m / 30m / sight.

Evokers and abjurers can step down the range categories to make the DC easier.

Table 5: Spell













Scorching Ray

Range: 10m, Ranged touch

Max. Damage: variable, max. chosen by caster

Attack: Spellcraft vs. Reflex

DC: 14+ max damage

Area effect: beam (1 target)

This spell has the base range of the evoker type, and variable damage up to the maximum chosen by the caster.

Base range: 0

Reduced area effect: -1 for beam

So in order to do maximum damage of 5 (enough to penetrate most armour) is DC 19.

Magic Missile

Range: sight

Attack: Guaranteed damage

Damage: fixed, 2 wounds

Area effect: single target

DC: 20

For guaranteed damage: +2=+2

Range extension: +2

Area effect reduction: -1

Note that this can be extended to multiple targets (+1 DC per additional target) and increasing the maximum damage by 2 only increases DC by 2.


Range: 30m

Area effect: 1 person

Attack: spellcraft vs. will

DC: 20

Sleep is a level 3 effect, +2 for the range extension. This gives a total DC of 20. DC can be increased by 1 per additional target.

————- Footnotes to table 2————–

[1] Assumes that the effect is somehow different to a variable benefit/damage, perhaps because it has penalties which partially offset the benefits

[2] Note Sleep differs from Paralysis: after 1 round, sleepers can be woken non-magically

[3] A minor spell effect is a spell which affects magic – draining charges, protecting against spells, etc. Other spell effects represent progressions from this.

I envisage  magic working very simply:

  • many characters can learn magic, either as a central skill or as dabblers
  • characters learn spells individually, almost like feats
  • all characters who use magic have a certain number of fatigue slots, equal to their concentration skill
  • all spells have a DC to cast
  • all spells are cast using either Spellcraft (for primary users of magic) or one of the save skills (Presence or Will) for minor users of magic
  • failure to make the DC means the spell works but the caster suffers fatigue; success means no fatigue
  • the difficulty to resist a spell is determined by the spell-caster’s skill roll in a challenged skill check
This retains the essential character of AD&D spells (they always work) but builds in the essential skill-based system of resolving saving throws which I want to base the system around. It incorporates the cost of casting into the one roll as well.
The two problems I have with this system are:
  • Defining  DCs: spells are really diverse with diverse effects, so it’s difficult to define DCs for  all of them. The simplest method is simply to set a level on the spell and make the difficulty from a formula based on the DC. I had been working on a set of rules (based on duration, range, maximum damage and type of effect) but this has not been very easy to generalise – for example, healing is a permanent effect, so any duration-type modifier has to increase the DC of a simple healing spell, in order that it be generalisable across other types of spell (such as fireballs)
  • Spell failure: to be properly consistent with a skill-based resolution system, spells should be able to fail like any other skill. The skill being used here is the skill of channelling some kind of essence or force into a physical effect. Obviously this is kind of challenging! So one should be able to fail.
I had earlier written that I don’t want to have a skill system which has categories of partial failure and partial success, but this seems like the perfect opportunity to introduce notions of partial failure and complete failure: complete success occurs if you beat the DC, partial failure if you just miss the DC, and complete failure if you really miss the DC. Partial failure can indicate the spell works but the PC suffers fatigue, while complete failure indicates fatigue and the spell doesn’t work.
So here is the simple method for determining how spells work:
  • level-based DCs
  • partial failure occurs if one misses the DC but beats a lower target (DC-level, for example)
The AD&D 3.5 system gives a clear way of setting out levels, so it should be easy to judge the level of any spell. This system only becomes challenging if one does away with spells and makes all magic skill-based (my ultimate goal), because then the DM has to make judgements about the level of an effect on the fly.
We’ll cross that bridge when we’ve burnt it…