Limiting the Skill Bonus from Magery

[VIVIT]

I'm one of those weird people who actually like basic magic, but what does bother me about it is a certain side effect of magery prerequisites: magery increases your effective skill with all spells, including spells that require a certain nonzero level of magery. It's impossible to know an IQ/Hard spell with a magery prerequisite of 3 at any level lower than IQ+1. The magery you have bought to satisfy the prerequisite increases your effective skill to the level you would normally get from putting 8 points into the skill.

My basic idea is to have Magery levels grant bonuses to spell skill only in excess of the spell's magery prerequisite. Thus, if you have only as much magery as is required by some spell A, your skill level with spell A is as it would be for any other IQ/Hard skill with the same number of points in it. If you have one more level of magery than required by the spell, your skill level would be +1 for that spell, and would receive a further +1 bonus for every additional level of magery. This rule is effectively equivalent to saying that all spells are cast a penalty equal to their magery prerequisite. For this purpose, magery prerequisites would be counted recursively: the penalty applied to a spell would be equal to the highest magery prerequisite in your prerequisite chain to that spell.

My concern is that this approach might be unidiomatic because relative to RAW, it effectively increases the difficulty level of certain spells beyond Very Hard; I would need to make spells IQ/Easy, including the VH ones, in order to keep them all within the range of difficulties that GURPS uses. ESCARGO has uncapped difficulty progression, but there are other misgivings I have about ESCARGO.

Tell me, SJGF: am I worrying too much?

[johndallman]

I would not worry about the idiom so much as the complexity of calculation. It seems very likely to result in errors in calculating spells' skill levels, which are important for resistance rolls and energy costs.

Certainly if a GM wanted me to use it, I would require him to do the calculations and produce numbers from which I would play, with errors being the GM's responsibility.

[Gumby Bush]

It might be better to remove the Magery prerequisites, or replace them with other prerequisites. Another option would be to swap out Magery adding to skill for one of the other ways Magery operates in other magic systems, adding a new "Magic Talent" to provide the skill bonuses.

One option for alternate prerequisites, and basing in part on RPM's use of Magery, just replace all Magery prerequisites with Magic ER 3*M, where M is the old Magery level prerequisite. This has the side effect that powerful wizards are likely to have more energy for magic--but needn't be particularly skilled.

[khorboth]

If I understand this correctly, it could be more simply phrased as:

Spells with a Magery prerequisite receive a negative equal to the amount of that prerequisite.

And that would keep the math the same. Is that correct, or have I misunderstood?

If I'm right, it seems... minor. IDHMBWM, but the vast majority of spells don't have that requirement. It's a pretty small tweak and I'm not sure it really gets to the heart of the problem.

I also have observed that it's pretty easy for magi to get to the point where every spell is learned at 15 with one point and in a fairly high-powered game, skill 20 for 1 point isn't out of the question. Is this the problem you're trying to address?

[evileeyore]

The simplest solution is to create a second Talent, call Wizard Talent [10/level], it applies to spells, Thaumatology, and Hazardous Materials (Magic) and then change Magery to being only 5 points per level after level 0 and it only applies to fulfilling Prerequisites, energy expenditure caps for spells, and to IQ for detecting magic.

[johndallman]

Originally Posted by khorboth

If I understand this correctly, it could be more simply phrased as:

Spells with a Magery prerequisite receive a negative equal to the amount of that prerequisite.

Afraid not. The thing that makes it more complicated is:

Originally Posted by VIVIT

. . . magery prerequisites would be counted recursively: the penalty applied to a spell would be equal to the highest magery prerequisite in your prerequisite chain to that spell.

So if you're calculating your penalty for a spell, you have to trace back through your prerequisites for it, find the largest magery requirement, and use that. This can't be pre-calculated for all spells, because of prerequisites like "10 Food spells" or "One spell from each of six colleges." It's different for every character.

In fact, I realise there's an aspect that makes it worse. It is at least theoretically possible that learning a spell could reduce your skill with one you already know, if you learn a spell with a high magery requirement that is in an alternative prerequisite chain for a spell you already know. You can fix that by saying that the penalty is the lowest one in all your alternative prerequisite chains, but that makes working out the answer even more complicated.

[VIVIT]

I ought to mention where this idea came from. It came from the spell charts PDF: each spell has its magery prerequisite marked with little dots, the number of dots corresponding to the magery level required by the spell, and it counts magery prerequisites recursively.

Originally Posted by johndallman

This can't be pre-calculated for all spells, because of prerequisites like "10 Food spells" or "One spell from each of six colleges."

Hrm. I hadn't thought of this. The way spell charts handles it is that these spells only have magery prerequisites marked if they have a named spell in that group (e.g. "6 Light/Dark spells including Blur") with a magery prerequisite.

In fact, I realise there's an aspect that makes it worse. It is at least theoretically possible that learning a spell could reduce your skill with one you already know, if you learn a spell with a high magery requirement that is in an alternative prerequisite chain for a spell you already know. You can fix that by saying that the penalty is the lowest one in all your alternative prerequisite chains, but that makes working out the answer even more complicated.

I have thought of this, though: I would rule that if a spell has more than one prerequisite chain and you satisfy both, the penalty is determined by the more favorable chain. So learning a spell can improve your skill level with another spell, but it can't make it worse.

If I do a more formal write-up of this house rule, I'll take these points into consideration.

[Plane]

If you're wanting super-low skills in the higher-level spells I would suggest B242's box on Alternative Magic System: Ritual Magic.

Instead of skills you must buy to know, they are techniques you'll know based on the college, a skill which defaults to your basic skill like thaumatology.

Penalty = number of prereqs, so those higher-level spells that tend to require Magery 3 will have many prereqs and start very low.

[VIVIT]

Yeah, I know about ritual magic. The problem with that is that penalties build up a little too steeply for my taste. Also not a big fan of being allowed to cast spells at default.

[Plane]

Well, you can't if it defaults to less than 3, which I could see happening.