Uninterruptable Magery

[Ternas]

Originally Posted by Ghostdancer

Which in GURPS usually means the less powerful a spell you can cast - I see no issue. I suppose a perk for a single spell is about right. Alternatively, use an Unusual Background.

I know that there's a perk called Combat Casting in Martial Arts: Yrth Fighting Styles (not sure if it shows up elsewhere) that improves it from Will-3 to straight Will, but it has to be specialized by spell. Might not be all the way for what the OP is asking about, but it's probably a lot better than the penalty.