Alternative Limitations
 

Power-Ups 4: Enhancements, p.13 presents "Alternative Enhancements". Is there a corresponding (preferably RAW) rule for limitations? Say I have a warrior capable of short bursts of speed, strength, etc., but at the cost of his body and will wasting away. The way this happens, however, can vary: Costs Fatigue, Costs Hit Points, Backlash, Cardiac Stress, Corrupting, Temporary Disadvantage (Lame, One Arm, Sleepy, etc.), Unsupported, etc. How would this work? On a related note, what about the rules for "Declining Enhancements" on Power-Ups 4: Enhancements p.17? Could I have an "Inclining Limitation" that increases in percentage reduction (maybe starting with Costs 1 FP, -5% and ending with Backlash (Unconciousness), -100%)?

Re: Alternative Limitations
 

There's a method called "Either/Or" Limitations (PU8, Limitations, pg 6) that gives you a value for being able to choose one of two other Limitations. Basically you multiply the value of the two Limitations together. (So, either a -40% Limitation or a -20% Limitation is a net -8% Limitation.) The value of being able to choose a Limitation on the fly is considerably less than a fixed Limitation, as it becomes very easy to avoid either Limitation actually coming into play. (They'd both have to apply to the use of the power; otherwise, the proper munchkin would simply choose the one that wouldn't actually affect his character, thus effectively never having a Limitation.)

Sorcery has an "Alternative Rituals" rule (p7) that as a specific case (rather than a generalized rule for any Limitations) lets you substitute any two of three possible spell-casting Limitations for the standard Costs 1 FP Limitation. PK generalizes the Either/Or logic to arrive at a result of half value for choosing any two of the three (or four) Limitations in the set, all normally -10% -- so choosing two -5% -5% = -10%, matching the standard Limitation. (Or so PK argues, as he is among the many that find that a more fair price for Costs FP than the book value of -5%.)

Re: Alternative Limitations
 

It has also been canonized in GURPs Power-Ups 8: Limitations (p. 6)