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…