Using Powers as a metasystem for spells

[cmdicely]

So, it occurred to me the other day, that GURPS has most of the pieces in place to build spells -- in the sense of abilities that cost fatigue and require a skill roll to use, but only requiring buying the skill, not an advantage (except maybe an access advantage like Magery) to use -- with all the detail and options in Powers.

Simple:

• Notice that devotional enchantment and certain other rules in Fantasy rely on a 25 FP = 1 CP equivalency
• Notice that SUPERS allows single-use Powers for 1/5 the normal cost
• So, it should cost 5 FP per CP cost of a power to buy one use
• Toss in Based on (Attribute) if the power doesn't normally have an activation role, and use Power skills, and you've got an ability that just needs Talent -- if its magic, Magery -- and an appropriate skill and fatigue expenditure to use.

[jeff_wilson]

Originally Posted by cmdicely

So, it occurred to me the other day, that GURPS has most of the pieces in place to build spells -- in the sense of abilities that cost fatigue and require a skill roll to use, but only requiring buying the skill, not an advantage (except maybe an access advantage like Magery) to use -- with all the detail and options in Powers.

Simple:

• Notice that devotional enchantment and certain other rules in Fantasy rely on a 25 FP = 1 CP equivalency
• Notice that SUPERS allows single-use Powers for 1/5 the normal cost
• So, it should cost 5 FP per CP cost of a power to buy one use
• Toss in Based on (Attribute) if the power doesn't normally have an activation role, and use Power skills, and you've got an ability that just needs Talent -- if its magic, Magery -- and an appropriate skill and fatigue expenditure to use.

You're going to need a LOT of FP or ER: 200 to fly and 25 for 1d of crushing or burning damage, 25 to 40 times more expensive than regular spell magic.

[PK]

I agree -- it seems like, for the cost of the ER you'd need, you're better off with some form of Modular Abilities.

[Refplace]

Originally Posted by Rev. Pee Kitty

I agree -- it seems like, for the cost of the ER you'd need, you're better off with some form of Modular Abilities.

Well those two replies are nice comments on balance. I would have vetoed the concept as GM but maybe not now in the right genre.

[cmdicely]

Originally Posted by jeff_wilson

You're going to need a LOT of FP or ER: 200 to fly and 25 for 1d of crushing or burning damage, 25 to 40 times more expensive than regular spell magic.

Regular magic spells often have the equivalent of lots of limitations -- ritual requirements, particularly -- which will reduce this somewhat. If you look at prerequisite count as a balance factor (which, even if specific prerequisites aren't, seems reasonable), you could add a limitation for that as well (assuming you wanted to use existing rules that rely on prereq count with spells constructed with this framework.) You'd probably want that to be small, maybe -5% times prereq count.

There's a hard limit to how much any set of limitations gets you with the -80% net limitation limit; personally, I prefer to weaken that limit by treating -80% as a breakpoint, and applying any additional limitations to the cost of the advantage after applying the -80% limitation (so, -160% net limitation is 1/25 cost.)

[jeff_wilson]

Originally Posted by cmdicely

Regular magic spells often have the equivalent of lots of limitations -- ritual requirements, particularly -- which will reduce this somewhat. If you look at prerequisite count as a balance factor (which, even if specific prerequisites aren't, seems reasonable), you could add a limitation for that as well (assuming you wanted to use existing rules that rely on prereq count with spells constructed with this framework.) You'd probably want that to be small, maybe -5% times prereq count.

There's a hard limit to how much any set of limitations gets you with the -80% net limitation limit; personally, I prefer to weaken that limit by treating -80% as a breakpoint, and applying any additional limitations to the cost of the advantage after applying the -80% limitation (so, -160% net limitation is 1/25 cost.)

I'm not seeing how you'd be able to stack up -160% worth of ritual limitations on most spells, how they would mix with the existing limitations, or how prereqs are valid limitations: Super Flight isn't discounted for requiring Flight to be bought first.

Maybe if you could find another 1/5 cost mod to stack with single use?

[Black Rose]

I have to admit, I like the idea of using the advantage rules, along with Powers, to build spells. I'm not nearly so keen on the hideous prices that would come from that. Now, if you used Powers to build the spell effects, then assigned "point values" to certain qualities -- e.g., Duration, Fatigue Cost, Casting Time, Magery requirements, Prerequisites, etc -- you could "buy off" the "cost" of a spell with such.

The idea would be that you aren't actually paying for the spells with CPs per se, but rather defining the "worth" of the spell, and then compensating for that with various small-l limitations on said spells, but not actually building those limitations into the spell writeup itself.

[martinl]

Originally Posted by cmdicely

• Notice that devotional enchantment and certain other rules in Fantasy rely on a 25 FP = 1 CP equivalency
• Notice that SUPERS allows single-use Powers for 1/5 the normal cost
• So, it should cost 5 FP per CP cost of a power to buy one use
• Toss in Based on (Attribute) if the power doesn't normally have an activation role, and use Power skills, and you've got an ability that just needs Talent -- if its magic, Magery -- and an appropriate skill and fatigue expenditure to use.

As others have noted, if you require immediate use of the FP, this is too expensive.

If you allow the FP to be "banked up" this is probably too cheap.

RPK is probably right that the traditional solution of modular abilities would work better.

[kure]

My advice would be, to not copy spells with powers.
At first its lot of work, the hard one. (i did it, and result wasnt that good) and there is some spells which even cannot be copied.
If you like to have hundreds of small single effect abilities, which cost fatigue, use spell system as it is. Or there is several options in Thaumatology books.

Powers are great to describe somewhat bigger and flexible abilities.
And you can easily adapt them. For example if I want to have powers like magic, I would just say that each ability should cost FP, cannot have "no signature" and if normaly unnoticeable (like mind control) should have visible.

That´s it. Well result is not same as spells, but is simple and add taste of magick.