Sorcery: Vancian Casting

Sorcery: Vancian Casting

You might be familiar with my wizardry framework that tries to replicate the flavor of a D&D wizard. (It's going to be reworked soon, I think - I've been getting some feedback on it). This post is just a thought experiment (at least yet), proposed by one of my friends. Let's try making Vancian casting in the powers framework.

First, what we'll need is the Preparation Required, Per Use limitation (Pyramid #3-105, p. 30) that allows us to prepare multiple instances of the same ability. We will also need Cosmic, Does not become inert, +100% from the same article. In addition, let's not forget interpolated Preparation Required modifiers from this post.

That Cosmic immediately jumps in front, attracting attention with its huge value. I think that the Gourmet Alchemy article where this enhancement is described should've had Preparation Required, Per Use on Super-Memorization, not on the elixirs. That way, you could also avoid this Cosmic enhancement, as Spell Slots (GURPS Thaumatology, p. 56) suggests treating Modular Abilities as a single ability for the purpose of the Preparation Required limitation. Personally, I think it would be fair to treat arrays of alternative abilities the same way - you will not need this Cosmic enhancement (I'm just trying to justify not doubling the point costs).

Also, let's take a look at page 5 of GURPS Power-Ups 8: Limitations. According to that book, a daily preparation ritual that lasts 1dx5 minutes (an average of of 17.5 minutes - let's round it down to 15 minutes) is equivalent to Requires typical ritual, -10%. But this implies that the ability simply works normally if you prepare it, it does not limit the number of uses. Let's double Requires typical ritual, -10% to Requires typical ritual, Per Use, -20%. If we look at the extrapolated Preparation Required table, we will see that 15 minutes should be equal to about -32%, that halved for "per use" preparations would be -16%. That's close to our -20%! So, we basically arrived to the conclusion that Cosmic, +100% isn't necessary, but in a roundabout way. Sort of.

But wait, the wizard also must have a written reference such as a spellbook or a scroll to prepare. Typically, that would require us to apply Requires spellbook, -10%, but since it is only required for preparation, let's reduce it to Requires spellbook to prepare, -5%.

But anyway, let's decrease the preparation time to 10 minutes to get a nice six spells per hour rate, and decrease the limitation to -15%. How do I introduce the spell slot limit? By making sell slots as an Energy Reserve. ER (Magic) costs 3 points/level. Let's give it Limited Use, 1/day, -40% to represent them being a pool that is replenished fully only when the caster gets some good sleep. Let's also give it Abilities Only, -10% to make them only power "casting costs", not extra effort or anything else. You can use this ER to power other magical abilities, but that way you will deplete your spell slots. I'm okay with that, there are some abilities like that in D&D. Having this ER will also allow us to build abilities that drain spell slots, again, just like in D&D. How do we enforce wizardly spells to only use these spell slots? We apply at additional -5% to the power modifier, as per p. P119. The FP cost will basically represent the "level" of the spell. A simple spell will cost 1 FP, requiring one spell slot to cast, while something more complex would require more.

Now, the wizard may prepare certain spells and spend his ER however he wishes. He could have ER 10 (Spell Slots), and prepare twelve instances of Fireball and five instances of Resist Fire, and then spend ER on whatever spells he had prepared. To make the wizard "reserve" ER in advance and to prevent overpreparation, let's give the power modifier another -5%.

Thus, we have arrived to the following power modifier: Wizardry, -40%. It consists of Cannot overprepare, -5%; Limited to using ER, -5%; Magical, -10%; Requires daily ritual, 10 minutes, Per Use, -15%; Requires spellbook to prepare, -5%. Note that it does not contain the casting cost.

ER (Spell Slots) will cost 1.5/level. For extra effort and all additional FP costs, the wizard uses his actual FP, not spell slots.

How does it interact with Modular Abilities/Sorcerous Empowerment? It really doesn't. If you want to plug this into sorcery, then you do not have to apply anything to the Sorcerous Empowerment, because all the limitations are included in the spells. You can limit the scope as normal though.

I think that's all, but I might be missing something.