Alternative Realm Magic[]
Realm Magic and Magery[]
Realm Magic has a Magery requirement: Magery (Realm). This is not stated explicitly, but it is assumed in several points of the text (see “Capping Syntactic Magic”, p.T184). That said, given how many points you’re spending on Realm Advantages, it’s probably not a big deal if you waive this requirement. Alternately, if the magic system stems from a source other than, well, Magic, you can change or replace Magery to better reflect that source: something like Blessed or True Faith to represent Divine magic; Higher Purpose for Morality-based magic; Trained By a Master or Blessed (Harmony with the Tao) for Chi-based magic; Oracle for Nature-based magic (druids famously watched the natural world around them for omens); Channeling or Medium for Spirit-based magic; Illuminated or Intuitive Mathematician for Savant-based magic (see GURPS Supers); Danger Sense or Empathy for Psionic-based magic; and so on. If need be, you can use an Unusual Background such as UB (Super).
Standardized Energy Costs and Casting Times[]
Per the rules as written, a Working will tend to cost more energy and take longer to cast if you go with many levels than if you only go with a few. As an alternative, base the energy costs and casting time on Relative Level, which is 6×(level/maximum level). This will bring the energy costs and casting times of Realms that have fewer than six levels in line with those of Realms that have exactly six levels. Alternately, standardize energy costs around 3×(level/maximum level); that produces more reasonable energy costs. But you can do even better by basing energy cost solely on the highest required Realm and basing the casting time solely on the number of Realms (say, one second per Realm). The goal is for the base energy cost for an Effect to be in the 1–4 range, and for the base casting time to be in the 1–3 range. By comparison, Verbs and Nouns (which doesn't require as much of a character point investment) has energy costs ranging from 1–7 and averaging around 3, and casting times ranging from 1–6 and averaging around 3 or 4.
Normally, every Realm in a given Realm system will have the same number of levels; but if your setting has multiple Realm systems, it's still in your interest to standardize the costs and times. And if you want to experiment with different Realms in a single system having different numbers of levels, this facilitates that, too.
Simpler Realm Pricing[]
Use Power Talent pricing from GURPS Powers, scaled by the number of levels the Realm has:
Base cost per level = 60 / number of levels. Multiply by a factor based on how broad or narrow the Realm is:
Broad Realm (equivalent to a 15-point Power Talent): ×1.5
Normal Realm (equivalent to a 10-point Power Talent): ×1.0
Narrow Realm (equivalent to a 5-point Power Talent): ×0.5
One benefit of this approach is that you can apply all of these options on a Realm-by-Realm basis: for instance, a mage can have a mixture of Narrow, Normal, and Broad Realms.
Conversely, this doesn't work if you're trying to cover everything with one to five Realms: even Broad isn't broad enough. For that, stick to the existing approach, possibly with finer steps:
1 Realm: ×5
2 Realms: ×4
3 Realms: ×3
4 Realms: ×2.5
5 Realms: ×2
Choose Your Own Progress[]
Instead of a hard-wired progression in the levels, let the player choose how he wishes to progress. One way to do this is to pick a number of Verbs from the Noun/Verb system and let the player choose one Verb per level. If you want, you could treat this as a set of parallel Advantages instead of a single leveled one: if the Realm is Matter and the levels are Sense, Control, Transform, Create, and Destroy, then you can write them as “Matter (Sense)”, “Matter (Control)”, “Matter (Transform)”, “Matter (Create)”, and “Matter (Destroy)”. Doing this changes how you determine the energy cost of a casting: use something like the way Noun/Verb energy costs are calculated instead, with each Verb having a cost associated with it, and a base cost of 2 added to that.
Protocols[]
A Realm is Noun-like, in that it’s defined in terms of what is subject to it, while the levels determine what sorts of things you can do to it. A Protocol inverts this: it’s an Advantage where the defining feature is what you can do, while the level determines what you can affect. Normally, this would require you to create a hierarchy of things you can affect, from most specific to most general. Sometimes, this is appropriate: an Alchemy system could use the four Alchemical Operations (Nigredo, Albedo, Citrinas, and Rubedo) as Protocols, with the first level of each defined in terms of base matter and gradually expanding to include complex machinery, life, and eventually abstract systems. But for the most part, you’d probably want to pair Protocols with a variation on Choose Your Own Progress.
Protocols and Realms can be used together, each supplying something the other lacks: If you have a Destroy Protocol and a Matter Realm, then you can use them in conjunction to Destroy Matter even if your Destroy Protocol lacks the ability to affect Matter and your Matter Realm lacks the ability to destroy. This is a bit like Noun/Verb Magic, except that you don’t need both if either has enough in it to get the result you want on its own. Using Realms and Protocols together might provide a cost break: a 4-point reduction would be appropriate. (Example: a magic system has a the Realms of Cunning, Dreams, the Elements, Health, Nature, and Spirit, and the Protocols of Knowledge, Luck, and Protection. If his levels in Spirit aren’t enough to offer protection against spirits and his Protocol of Protection doesn’t cover spirits, he can still use his Protocol of Protection together with his Realm of Spirits to protect against spirits.)
Effect-Shaping and Energy-Accumulating Realm Magic[]
As written, Realm Magic uses a minor variation of the spell casting rules from the Basic Set: spend a number of seconds concentrating, pay an energy cost, and roll the dice. Your skill level might affect both of these factors and may also require you to chant and/or gesture while concentrating, with higher skill requiring fewer of these ritual elements. Practices (pp.T192-193) expand on those requirements. But it’s also possible to replace the entire thing with either of the ritual systems from Chapter 5. Energy Accumulating is the easiest one to implement: just abandon the “time to cast” elements and use the Energy Accumulating rules to gradually gather the necessary energy. Effect-Shaping is slightly harder: take the Time to Cast in seconds and read that as steps on the Duration scale to determine how long the ritual will take; then subtract two from the energy cost and read it as a skill penalty instead of an energy cost.
Note that these magic systems generally assume larger areas, longer ranges, and longer durations than the regular system, to go with their much longer energy costs. This is reflected in the way Parameters work in regular Realm Magic, contrasted with how Ritual Parameters work in the Effect-Shaping and Energy-Accumulating models. [This requires modifying the Duration table for use with spell-casting Realm Magic: insert three levels between Momentary and 10 minutes: 1 minute, 2 minutes, and 5 minutes. “Momentary” effects also include one-second Effects; the distinction matters when spells can be Maintained.]
Realm Magic and Sorcery[]
You could merge Realm Magic and Sorcery by replacing Sorcerous Empowerment with a set of Realms corresponding to the sorcerous colleges, then have each college’s Spells work as Alternate Abilities to the college’s Realm. In this Sorcery variant, improvised spells can be quite potent, sometimes even more potent than Learned Spells; but they require a lot more time and effort. Having multiple Realms means that you can cast one spell at a time per Realm, rather than just a flat one spell at a time. If you do this, the Sorcery Talent adds to the Realm Skills as well as to Spell casting. Magery should either be limited to Magery 0 or it should act as a cap on Realm skills — which brings up the question of what happens when a Talent and a skill cap collide.
Realm Magic as Alternative to Powers[]
It’s also possible to modify the Realm Magic system to produce an alternative to the Powers system. With this option, your levels in the Realm don’t determine what you can do; they determine how much you can do: if you succeed, add your Realm levels to your margin of success, and add your margin of success to your primary Parameter. This system has a base cost of 10 points per level in a Realm, modified as normal; the cap on how many levels you can have, if any, is determined by the GM. Instead of being a single Very Hard skill that covers the entire Realm, you buy a separate Hard skill for each Spell (use the guidelines from RPM for Specific Definition, p.19, to determine what a Spell covers). If you wish to maintain the flexibility that Realm Magic normally offers, you can have all Spells in that Realm default to each other at, say, -2. Alternately, you can use a variation of the Choose Your Own Progression option, with each Verb for the Realm being a separate Very Hard Skill and each spell either being a Technique (in which case you’d need to determine a reasonable Default penalty) or an optional Specialization.
(The above was patterned after the power system found in GURPS Classic Supers.)