Converting Shadowrun Magic to GURPS

[Jürgen Hubert]

Another idea: The Force of a spell represents the maximum Margin of Success you can have on your relevant skill roll. This Margin of Success is relevant for the overall damage of combat spells, resisted rolls for illusion/mind control spells, and so forth.

If your actual Margin of Success is higher than the Force of your spell, then any additional points of Margin of Success reduce the fatigue cost/drain of the spell.

So if you want to "play it safe", cast the spell at a low Force rating and you will have very good chances of reducing the fatigue cost of the spell. But if you want to go all out, cast it at a high Force - but then some fatigue is almost guaranteed.

This also simplifies the success roll and the drain resistance roll into a single roll.