Mechanics: Vanilla Magic and Threshold-Limited Magic

First not-so-scary and on-topic
GIS result for vanilla and overload.

Earlier this week I did a very shallow look at various magic systems I either actually used and like or pontificated they would be good systems to run. Today, I'll discuss the similar, but different default systems and the threshold-limited system from Thaumatology. The systems do have some big differences that make them interesting enough to definitely consider them two different things, but they share so much, I'd probably be copying and pasting paragraphs if I did this twice. Now that we've seen things in very broad strokes I am going to drill down into more mechanical explanations. Hold onto your coats and mittens, as we enter the wild world of rules rules rules!

Magery

The root of both forms of magic is the advantage Magery. Magery is described in the basic set and probably several other locations as well. It acts as both a limiter in the form of a prerequisite for high level magic skills, and as a wide sweeping talent. That is, each level of Magery actually gives a bonus to all spell casting. 

For this reason, large investments in magery are usually in the best interests of characters that want to be able to cast very powerful magic. Additionally, every magic spell is an IQ based skill so investing heavily in IQ with or without Will and Perception is another cheap way to increase system wide aptitude.

A GM is thus recommended to limit the amount of Magery a player can start with to around three levels [Aside: I'm not sure if this is official advice, or just a popular house rule] and think carefully about buying more Magery.

Magery being the gateway to all casting [except in weird circumstances involving high mana and the like] there are other options for the GM that wants to reign in power levels or have a different ambiance from omni-capable omni-powerful wizards. In the basic set, page 67, for example, there are several limitations that can be applied to the Magery advantage, most appropriately for this theme, of controlling limits, the One College Only limitation [the other limitations presented are all interesting, but limit the player with weird hoop jumping antics without necessarily limiting what magic can be cast. Thaumatology on p.19 has more options, specifically, advice on limiting Magery to different colleges, or requiring a different magery per college, but many other interesting limitations are spelled out too. 

In Thaumatology, on p.67 also gives some interesting methods of adjusting Magery under the deceptive title "Power Investiture as Modified Magery." It allows making a specially themed set of spells (eg, clerical magic for clerics, hence the heading of that section) with some interesting modifications to mechanics like adjusting prerequisites or removing or adding side benefits to Magery.

Energy

This is the biggest divergence between the two systems. What separates the two is how energy is consumed and recovered.

Vanilla

In basic set, magic was cast from FP, and only from FP. Thaumatology adds the concept of "Energy Reserve" which is also used in Dungeon Fantasy, it almost acts the same as regular FP except for the limitation it can only be used for magic, and the advantage that it recovers passively, and individually of regular FP. Besides that, large amounts of FP can be stored in the form of Powerstones, basically trading money for magical FP. Good powerstones can be incredibly expensive, and usually recover energy very slowly, or can only recover by paying an expert in the case of Dungeon Fantasy. High spell levels can give energy discounts, and keeping long running spells from ending through maintenance is cheaper if the spell needs to run for a long time.

Threshold-Limited

The flavor that distinguishes threshold limited magic from plain magic is that players are granted a great reserve meaning powerful magic is possible, but with severe consequences for abuse.  As a matter of fact, there isn't really a definitive limit to what one could do with Threshold-Limited magic, baring a character is willing to live with some pretty devastating consequences for performing world shattering magic.

As spells are used, a "tally" is kept, if this tally crosses the "threshold" (see that clever name drop?) then a calamity can occur, and one rolls against the calamity table. It has a form similar to the fear check table with some leeway for good rolls, but much worse consequences for bad rolls.

Threshold-Limited magic, though having a larger (or nigh infinite reserve) has a much slower recovery time than Vanilla magic, which again lends to a flavor of magic for powerful effects and only in emergencies. Similar to vanilla magic, Thaumatology has important advantages for increasing the level where consequences are incurred, and increasing the speed at which threshold recovers. With enough of both, a character might have the best of both worlds.

In fact, there is an option in the form of a fairly expensive advantage, Variable Energy Access which literally gives you the best of both worlds, allowing a character to cast spells using the energy rules for vanilla or threshold-limited as convenient.

Learning Spells

Spells are the same in both systems. Spells have a kind of prerequisite tree with strong spells requiring more fundamental spells. A character needs to learn to do simple elementary manipulations before doing something more fantastic. Let's take a Fireball spell, for example. One of the simplest projectile spell memes in all manners of fantasy role playing. A lot of wizards could put it to good use, but to learn Fireball, a user needs Magery 1, Create Fire,, and Shape Fire. Create Fire needs Ignite Fire, or Seek Fire. Shape Fire needs Ignite Fire. So, in order to learn one of the simplest magical attacks, you must learn at least three prerequisite spells first. This adds to the flavor and a lot of players enjoy this natural progression of magic. Spells are simply skills, and can be leveled as any other skill.

Using Styles

Pretty good resource for any
system based on the default spell
system. Ok one for everything else.

Styles allow a GM or a player to create a flavor of a cohesive body of knowledge being used by certain groups. A Fire Magic style like Pyromancy in Dark Souls, or a healing based style like clerics in many video games or other table top systems, for example.

And styles are not just a box that says, "you belong to this style, you can't learn anything but this list," but also a catalyst for powerful perks that allow characters to do things with magic that they normally couldn't, or giving advantages like those mentioned in Adjustable Spells mentioned on p. 39 of Thaumatology.

Adjustable Spells

This is a customization mechanic, as mentioned just a sentence ago that allows one to use advantage modifiers like those found in the Basic Set or Powers against spells. This way, we could increase rate of fire or throw fireballs overhead, for example. Included are some mechanics for creating techniques or perks with these abilities in mind. These perks might apply under styles, listed above, thus completing an Oroborous Cycle where Adjustable Spells help Styles, and Styles help Adjustable Spells.

Good Supplements To Look At

• GURPS Magic is basically required for either of these systems.
• If you really like magic, that same page recommends several expansion books with more official spells.
• GURPS Thaumatology is needed to understand the full rules of Threshold-Limited Magic 
• GURPS Thaumatology: Magical Styles also adds a great deal of perks to the mix and has some good advice for grouping thematically appropriate spells and abilities to give magic users more focus and better abilities.

Conclusion

I received feedback that my previous articles were interesting but a little shallow, I intentionally wanted to leave it a little detail sparse because I didn't want to just do a total data dump; more like I wanted to give an at a glance look to whet imaginative appetites. Glad people found them interesting. I have used the regular magic system several times, but haven't found a good opportunity to use threshold limited magic in real life yet, so there is a bit of conjecture here.