GURPSよろず

　The following optional rules are designed to add more flexibility to standard spells – at a cost. They make attack spells much more versatile, and can also be applied to other magic. Being almost open-ended, though, they’re not for everyone. The GM needs to know the rules in sufficient detail to spot abuses and prohibit applications that produce weird or excessive results. The players require similar knowledge to prevent play from bogging down.

　The basic principle is that wizards can add enhancements to spell effects – as if to an advantage – by spending additional energy and taking a penalty to effective skill at the time of casting. Each +1 energy and -1 to skill allows +5% worth of enhancements; e.g., by spending +4 FP and taking -4 to his spellcasting roll, a wizard could cast Lightning with the No Signature enhancement (+20%), enabling him to shoot invisible bolts. The extra energy cost counts as part of the spell’s cost. The totalcost is reduced normally by high skill, and can be paid by any energy source permitted in the campaign. The wizard can use options such as Trading Energy for Speed and Skill (see boxed text) to improve his skill roll. If the spell is given the Rapid Fire enhancement, the caster must pay the standard casting cost (reduced by skill) for each shot, plus the extra cost for the enhancement (once).

　The GM may opt to let wizards improve each combination of spell and enhancement as an Average technique.
Such techniques have a maximum level equal to the underlying spell skill.
Improving a technique doesn’t affect energy cost in any way.

　Example: Fireball with the Guided enhancement (+50%) is a technique that defaults to Fireball at -10. Raising Fireball/Guided to skill-4 would cost 6 points. The maximum level equals Fireball, for 10 points. Regardless of points spent, guided fireballs always require an extra 10 energy.

　Some enhancements come in levels, in which case the wizard may choose how many levels he uses when casting.
He can never cast with an effective skill higher than the underlying spell, however.

　Example: A wizard with 5 points in Fireball/Increased Range could cast a Fireball with 2× range (+10%, -2) or 5× range (+20%, -4) at his full Fireball skill; one with 10× range (+30%, -6) at a net -1; one with 20× range (+40%, -8) at -3; and so on.

　In all cases, the technique modifier still applies if other enhancements are added to the spell.

　The GM may give all spellcasters free access to these rules, but this will make them significantly more powerful for no point cost.
A better option is to require wizards to buy perks – either one per spell to which they can apply these rules (“Spell Variation”) or one per enhancement that they can apply to any spell (“Spell Enhancement”), at the GM’s option.
The latter may be preferable, because it lets the GM explicitly state which enhancements are available.
For a more limited version, the GM could require one perk per specific variation applied to a particular spell (e.g., “Enhanced Spell: Armor, Cosmic”).
A more generous approach would be to permit any variation if the wizard purchases a single Unusual Background (“Trained to Vary Spells”), priced as the GM sees fit.
In all cases, there may be additional prerequisites, such as a minimum level of Thaumatology skill.

　The effects of this option essentially overlap with a number of existing spells.
For example, Fireball with Explosion (p. B104) is much the same as Explosive Fireball, while Meta-Spells such as Penetrating Spell and Throw Spell have effects similar to various enhancements.
To give wizard PCs distinct personal styles, the GM may let them decide to use a few spells plus Spell Variation or a wide range of different spells – their choice. It’s equally reasonable to tell players not to bother taking any spell that can be effectively emulated by applying these rules to another spell, to keep things relatively simple.

　If wizards can use Adjustable Spells(Thaumatology,pp. 3940) to add enhancements to spells, then as explained there, the GM might require them to buy one of three classes of perks:

　You can add one specific enhancement to one particular spell, and raise the modified spell as a spell technique.
Enhanced Spell (Fireball/Guided) would let you add the Guided enhancement to Fireball and learn the Fireball/Guided technique.

　You can add one particular enhancement allowed by the GM to any spell it suits, and improve the modified spells as spell techniques.
For example, Spell Enhancement (Guided) would let you add the Guided enhancement to any Missile spell, and buy up Fireball/Guided, Ice Dagger/Guided, Stone Missile/Guided, etc.

　You can add any enhancement the GM allows to one specific spell, and learn the modified spells as spell techniques.
For instance, Spell Variation (Fireball) would let you add Guided, Increased Range, and other attack enhancements to Fireball, and improve techniques such as Fireball/Guided and Fireball/Increased Range.


　It isn’t mandatory for a single approach to hold campaignwide.
Styles concerned with thaumatological fundamentals might include Spell Enhancement perks, applying general principles to all spells.
Those that teach a narrow spectrum of closely related spells may allow Spell Variation for them all, so that few spells function as many.
And Enhanced Spell could show up in structured, non-improvisational styles.