GURPSよろず

Skills for Everyone
　In many settings, powers need training to be useful. As explained in Learning Powers (p. 35), the GM can require individuals with powers to train if they wish to add or improve abilities.
Another, fully compatible option is to associate each of a power’s abilities with its own “power skill.” Heroes might learn power skills through trial and error (typical of super-powers), or seek training from ancient masters (traditional for chi, magical, and spirit powers), academies (appropriate for psi and magical powers), or monasteries (especially for chi or divine powers).
When using this option, a power skill exists for any ability -- passive or active -- that requires an activation roll (not just an attack roll).
This is a Hard skill named after the underlying advantage and based on its controlling score.
Those who possess the ability must roll against the associated skill to use it.
Unskilled users roll at default: (controlling attribute)-6.
Talent benefits both trained and default use.
Individuals who lack the ability can’t learn its skill or use it at default, even if they have the correct power and a high level of Talent.

Example: Healing is based on IQ. If the GM requires skills to use psi powers, a psychic healer with Healing must roll against Healing (IQ/Hard) to use his ability – or at IQ-6 if untrained. In either case, his Healing Talent gives a bonus.

　The GM decides which powers require skills, and for which abilities.
This has no effect on the cost of power modifiers or Talents, as the shortterm drawbacks balance the long-term benefits. Those without training do have a large penalty (-6 for working at default) relative to individuals with “wild” abilities or powers that don’t require skills. Even trainees who know the skill have a small penalty at low levels (-2 or -1 with only 1 or 2 points in the skill). Ultimately, though, they can buy as much skill as they wish, allowing them to perform feats far beyond the capabilities of those limited to just attributes and Talent.