[RPM] [Sorcery] Merging the Systems

[Varyon]

Originally Posted by PK

Sure. Replace Sorcerous Empowerment with Ritual Adept + levels of Magery (Ritual Path), and use RPM for "improvised magic" instead of sorcery. That way you have fast, easy "sorcery evocations" and slow, versatile "RPM rituals."

This bit over in the release thread for GURPS Thaumatology: Sorcery intrigued me, but I'd like to take it a step further. One issue with it is that Powers (including Sorcery) function differently from RPM Rituals - you can't "hold" a Sorcery Fireball, or deliver it with a punch rather than by flinging it, but you can do both of those things with an RPM Fireball. Another issue is that the methods build the spells differently - a 3d Sorcery Fireball is Innate Attack 3d (Burning, Sorcery -15%) [13], while a 3d RPM Fireball is Greater Create Energy (6) + External Damage 3d Burning (0) = 18 energy (6x3).

I'd prefer to have unity in build (so that each ritual doesn't run the risk of needing to be built twice) and effect. I personally prefer the way RPM rituals are built and work to a Powers approach, although I see the need to maintain the Ritual component of the Sorcery modifier (the bit about gestures, words, and/or FP cost) to prevent Known Rituals from being superpowers.

Ideally, I'd like to have an energy cost to character points conversion factor. I realize no factor is going to be perfect - Powers and Rituals are simply built too differently. For example, we see above that with a 3d fireball, (Energy/1.4) or so will give us an appropriate character point cost. If we bumped this up to 6d, the Sorcery build is [26] and the RPM build is 30 energy - (Energy/1.15) would be a more appropriate conversion factor here. On the other hand, No-Smell (Sorcery 13) is worth [63], but building it under RPM is either 60 energy or 201 energy, depending on if the GM requires the Altered Traits, or if Greater Destroy Matter alone (along with Subject Weight, Range, and Duration) is sufficient to remove scent.

I'm personally leaning toward using (Energy/2) to determine character point cost, primarily because it makes the math extremely easy - divide energy by 10 to determine cost as an Alternate Ability. What do others think?