Sorcery variant
 

Thinking of modifying Sorcery so that Hardcore improvisation adds to Tally, as per the Threshold system (Thaumatology pp. 76-82). Any thoughts on how you'd need to modify threshold and tally recovery to make this work?

Re: Sorcery variant
 

If you're talking about simply always having the 3 FP cost (and any FP cost for bonuses to the attempt) for Hardcore Improvisation instead apply to threshold, I suspect the default threshold system may work as-is - sure, he can manage a lot - up to 10 attempts in a day - of improvisations, but he'll have to lay off it for a while afterward.

If you're talking about getting rid of the cost and the Will roll, I'd probably just boost the cost of the improvisation to enough to give a net +4 bonus (yes, you normally can't get a bonus, but we'll ignore that here), like a "routine" task. So, improvising a spell up to 25% of point value is +11 to threshold, up to 50% is +13, up to 75% is +15, and up to 100% is +17. Optionally, simply getting the effective roll up to 16 may be good enough (so that higher Will/Thaumatology means hardcore improvisation is less damaging).