Ritual Path Magic & Rolling For Decans

Apollonian · 10-03-2016, 04:12 PM

I'm trying to hash out a GURPS Cabal campaign document using W.A. Frick's excellent Hunting the Cabal article in Pyramid 58 as well as Thaumatology: Ritual Path Magic, and I've run into a snag regarding the decanic modifiers. Specifically, I want to use the Rolling For Decans shortcut for those times when the players (or I) don't want to spend the time scraping together the proper correspondences for a ritual. As written, the caster just makes a Thaumaturgy roll and applies the margin of success as a modifier to his actual spellcasting... but that looks like it was based on the original write up of Sephiroth/decanic modifiers in Monster Hunters 1 and Thaumatology. T:RPM does it a little differently; namely, the decanic modifiers are calculated up to provide an energy discount on the cost of the spell, but don't add to the actual spellcasting roll. (At least, near as I can make out.)

So here's my problem: I want to be able to replace the decanic modifiers with a simple Thaumaturgy roll, but I need a reasonable formula, table, or other method for turning Margin of Success into a discount ranging from -1 to -45%. This method shouldn't be better than actually going out and doing the math, but it shouldn't punish players who don't want to take the time to do so.

My initial thought is something like "Roll Thaumaturgy. Multiply your margin of success by -5; this gives you the % discount on the cost of the ritual, to a maximum of -35%. On a critical failure, you are at -1 to casting the spell, as you've inadvertently included correspondences that oppose the ritual's intent." Are there any pitfalls to this ruling that I might be overlooking, or can someone offer a more elegant solution?

10-03-2016, 04:12 PM	#1
Apollonian Join Date: Aug 2004 Location: Shoreline, WA (north of Seattle)	Ritual Path Magic & Rolling For Decans I'm trying to hash out a GURPS Cabal campaign document using W.A. Frick's excellent Hunting the Cabal article in Pyramid 58 as well as Thaumatology: Ritual Path Magic, and I've run into a snag regarding the decanic modifiers. Specifically, I want to use the Rolling For Decans shortcut for those times when the players (or I) don't want to spend the time scraping together the proper correspondences for a ritual. As written, the caster just makes a Thaumaturgy roll and applies the margin of success as a modifier to his actual spellcasting... but that looks like it was based on the original write up of Sephiroth/decanic modifiers in Monster Hunters 1 and Thaumatology. T:RPM does it a little differently; namely, the decanic modifiers are calculated up to provide an energy discount on the cost of the spell, but don't add to the actual spellcasting roll. (At least, near as I can make out.) So here's my problem: I want to be able to replace the decanic modifiers with a simple Thaumaturgy roll, but I need a reasonable formula, table, or other method for turning Margin of Success into a discount ranging from -1 to -45%. This method shouldn't be better than actually going out and doing the math, but it shouldn't punish players who don't want to take the time to do so. My initial thought is something like "Roll Thaumaturgy. Multiply your margin of success by -5; this gives you the % discount on the cost of the ritual, to a maximum of -35%. On a critical failure, you are at -1 to casting the spell, as you've inadvertently included correspondences that oppose the ritual's intent." Are there any pitfalls to this ruling that I might be overlooking, or can someone offer a more elegant solution?