Poking at Four "Flavors" of Magic (Variations of Realm, RPM, or Incantation)
 

Egocentric Magic - the magic of the Mind and Self. This is for magical effects that are often considered psychic in nature: telepathy, astral projection, clairsentience, etc. In GURPS terms, this magic would be powered by FP and/or an Energy Reserve (Magic).

Ecocentric Magic - the magic of the Environment, drawing on the ambient magical energies surrounding us or from places of power such as ley lines and nexuses. Commonly used to perform the most common effects such as wards, shields, fireballs, growth and shrinking of the self and others, eldritch blasts, etc.

Exocentric Magic - the magic of the Beyond, drawing on mystic energies from farther out in the multiverse, often by contacting or invoking powerful entities. Spiritual contacts granting energy are common; generally the entities are entreated/invoked for powerful effects (you don't contact Cytorrak or Watoomb for a basic magic missile spell after all; you call upon them for the Crimson Bands of Cytorrak or the Winds of Watoomb, their "signature" spells).

Necromantic Magic - the magic of Death. Here, the energy is drawn from creatures by killing them, using the murdered creature's FP instead.


The Egocentric, Exocentric, and Necromantic flavors of magic are easy to work out for Realm, Path/Book, Ritual Path Magic, and Incantation. But the Ecocentric is bugging me. How do I make it mechanically distinct?

Re: Poking at Four "Flavors" of Magic (Variations of Realm, RPM, or Incantation)
 

It sounds like Ecocentric is the only one that is dependent upon local mana - Egocentric you are the one supplying the mana, Exocentric you're getting it from extradimensional beings (presumably in the form of something like Energy Reserve with Fickle, Pact, etc), and Necromantic you're getting it from killing things.

So, the others work fine with No Mana, Low Mana, etc, but you've only got a relatively small pool of mana to work from. Ecocentric has a much larger pool, but only if you're in an area that has mana (and it needs to be compatible mana - water spells aren't so easy in the desert) - and optionally, overuse might temporarily reduce an area's mana level or have other consequences (you may wish to adapt Threshold magic, but have it apply to an area rather than to a person). I'd personally be inclined to make the others be fairly quick to cast, while Ecocentric takes longer to gather the magic.

Re: Poking at Four "Flavors" of Magic (Variations of Realm, RPM, or Incantation)
 

How do mana levels work with open-ended systems like Realm, Path/Book, RPM, and Incantation magic?

After thinking about some things, I can see ecocentric magic relying at least in part on stuff like powerstones/manastones as well as the usual places of power (the Pyramids of Giza, the Nazca lines, 177A Bleeker Street in Manhattan, etc.). Just not sure how it all fits together from a GURPS standpoint.

Re: Poking at Four "Flavors" of Magic (Variations of Realm, RPM, or Incantation)
 

I am not quite getting the point of the entire thing. RPM tends to overwhelm the other systems, especially as point totals increase. Due to the massive CP expenditure associated with Realm magic, it tends to severely lag behind RPM for the same CP of characters.

For example, let us take a 400 CP character. A RPM mage can take IQ 20, Magery 6, Ritual Adept, and all ten magical skills at 18 for 325 CP. They are not only master magicians of note, they have energy reserve 18 and 24 conditional rituals, they are also cinematic supergeniuses that are capable of handling most tasks.

Conversely, a Realm magician in a 9 Realm/6 level schema cannot even get IQ 12, Realm 3 in all Realms, and skill 10 in all of the Realms for the same cost as the RPM mage. Now, a Realm mage could specialize in a couple of Realms, but they do not have an energy reserve or conditional rituals, so they will likely always be falling behind the RPM magician when they expand beyond a couple of Realms.

Re: Poking at Four "Flavors" of Magic (Variations of Realm, RPM, or Incantation)
 

Entirely up to the GM to my knowledge. I'm only really familiar with RPM, so I'll be assuming that here. It could manifest as a general bonus - or penalty, for low mana - to skill (like an RPM Place of Power, although I don't think there are places that give penalties in that), for example. Personally, I'd be inclined to have it serve as a % reduction - or increase for lower mana - in the amount of energy you need to gather to cast the ritual. Alternatively, albeit more finicky at the table, you could have it serve as a multiplier to energy gathered (retain fractions). For % reduction, I'd suggest high mana go no better than -50%, but the limit for low mana is +infinity (for no mana); I'd suggest +5% steps. If going the multiplier route, x2 would be the limit for high mana, x0 for no mana; I'd suggest 10 steps in either direction (1.1, 1.2, 1.3; 0.9, 0.8, 0.7; etc)

If you can bring eco-mana with you (in the form of powerstones or similar), such would not be affected by the reduction/increase. If using % reduction, figure out how much mana you'll be pulling out of storage, and subtract this from the cost of the spell before applying the modifier. If using multipliers, mana pulled out of storage simply isn't affected by the multiplier.

On the topic of powerstones, it seems like they'd be compatible with any of the flavors, although any given powerstone is probably only usable with one (and certainly any charged powerstone only works with the one it's charged for). For egocentric, you can charge the stone from your own internal reserves. For ecocentric, you need to gather mana from the environment and place it in the stone. For exocentric, you need to petition the entity to charge the stone for you, and it may well only be usable for that entity's "signature" spell(s). For necromantic (which I'd be tempted to call necrocentric, for consistency), you can bind a slain creature's mana into a stone (similar to soul gems in The Elder Scrolls).

Re: Poking at Four "Flavors" of Magic (Variations of Realm, RPM, or Incantation)
 

Ecocentric reminds me of the Threshold Magic rules. The mana is "out there", rather than Egocentric's "in here". So you don't have an ER/FP. You just pull from the environment. There's only so much mana out there, though, which is where the Threshold and Recovery stats come in. Stay in one place, throw a lot of spells, and you run out.

Flavor tweaks to throw in at this point could be a shared environment Threshold, where multiple mages are all drawing from the same pool, or making sure to decouple that Threshold from the mage's person, so if they teleport to a distant area, the local Threshold is recovered. (Or already unexpectedly drained by that last selfish mage to come through.)

It also might be fun to make the exact effects possible (or at least easy) depend on the local magical environment. Perhaps plant spells are easy in the jungle and hard in the desert, or mind magic is hard in cities from all the interference, or whatever. Then you'll probably need some sort of multiplier per category so you can count those plant spells in the desert as "harder" by burning up more local Threshold to pull it off. (Annoying, but it seems easier than adjusting the individual spell costs for the environment. Same idea either way, just a matter of where you want to do the math.)

You could adapt those rules to the points needed to cast spells with other mechanics like RPM or Realm Magic. It doesn't have to use spells-as-skills. Whatever resource the mechanics use as a metric, just assume it's Eco-supplied and count it in the Threshold.

Re: Poking at Four "Flavors" of Magic (Variations of Realm, RPM, or Incantation)
 

For Path/Book, see p. 126 of Thaumatology. Those rules are optional, depending on the GM's view of the relationship between different kinds of magic.

Realm magic doesn't mention mana, except in its enchantment rules.

RPM has similar rules to Path/Book, on p. 43 of T:RPM.

Incantation Magic uses mana, which gives skill modifiers, as per p. 10 of DF19: Incantation Magic.