If your game calls for a magic system that features a technology-like predictabiliity and scientific metaphysics, then the Deterministic Magic System (DMS) might be the option for you. If you're a refugee from a system like D&D or Pathfinder, this might be for you.

There is a spell list of spells with set in-game effects, which is organized according to the power of the spell. (When I say "There is a spell list," I mean: go create a spell list.) The simplest spells, with the least effect, are called cantrips. Spells of correspondingly higher and higher complexity and effect are grouped into "Spells of the First Circle", "Incantations of the Second Circle," etc.

Each grouping of spells becomes a TRAIT for the character. So for example, Tim the Enchanter might have traits of: Cantrips (Good +3/5D) and Initiate of the First Circle (Fair +2/4D).

Under each of these TRAITS, individual spells are TWEAKS. To continue the example with Tim:


In the DMS, casting a spell works like resolving any other character action, using any other TWEAK. The Success Target of a spell casting is equal to its "Circle" in successes, with the lowest grouping of spells (Cantrips) needing one success.

Thus for Tim to cast Read Arcane Runes, he could elect to spend a PLOT POINT to tap the TWEAK (see the ACTION RESOLUTION section of PPC), or he would roll 5D (4D TRAIT + 1D TWEAK), hoping to achieve at least 2 successes, since the spell is a First Circle spell (one above the lowest level).

Spell Level Success Target
Cantrips +1
First Circle +2
Second Circle +3
Etc ...


When the attempt fails or achieves a marginal success, the GM and player narrate an appropriate arcane complication to the resolution of the spellcasting.

For example:

  1. A surge of uncontrolled magical energy stuns everyone in the room.
  2. The spell strikes the caster or an ally instead of the intended target.
  3. The spell takes effect at a random location within the spell's range.
  4. The spell's effect on the target is contrary to the spell's normal effect.
  5. The spellcaster suffers some minor but bizarre effect related to the spell in some way.
  6. A random innocuous item or items suddenly appear in the spell's area.
  7. The spell's effect is delayed. Sometime within the next few hours, the spell activates. The spell goes off in the general direction of the original target, up to the spell's maximum range if the target has moved away.
  8. The caster can't cast spells for 1D rounds.
  9. The caster is dazed for 1 round.
  10. The caster is knocked unconscious.
  11. The casters hair stands on end for 1D rounds.
  12. The caster aquires a squeaky voice.
  13. There is a very loud noise, like a bang, in addition to the failure to cast the spell.
  14. An enormous shower of lights appears around the caster illuminating him for all to see.
  15. Anything held by the caster explodes into fire and forces her to drop it (no damage though).
  16. The caster turns a neon color for 1D hours.
  17. A random location on the caster's body is rendered paralyzed for 1D rounds. If this is the head or chest the character is prone but still conscious.
  18. A spirit, demon or extraplanar entity is summoned to the area.
  19. A person, object, building or portion of the terrain is teleported from some other part of the game world to the caster's location.
  20. The caster's mind is slowed, and further castings take 1D times longer than normal.
  21. The spell works twice as well as expected.
  22. The caster ages a full year in an instant.
  23. Wild magical energy bursts forth, disfiguring the caster and stunning her for 1D rounds.
  24. The caster attracts the enmity of a demon, who attacks immediately.
  25. All of the hair on the caster's body falls out.
  26. Some hideous monstrosity from the Underworld or Outer Void becomes greatly enamored of the caster.
  27. The caster gains some previously unknown arcane knowledge, but loses some currently held.
  28. Every being in the game world who died on this day is suddenly alive again, having spent a few hours in the Underworld.
  29. Ooops, caster dies.