New Mastery abilities?
https://forum.atlas-games.com/t/new-mastery-ideas/7167/1
Given that we're following this format for spell mastery? ((Are we, I thought I mentioned this already, and had approval, but seem to be blind for finding this, so consider this a request, if it hasn't been made already, and if it has, point me to where we're in agreement!))
So...I've been thinking about mastery, and that there should be some limit to integrating all these mastery abilities that magi can develop over time. Truthfully, the barrier to Quick Casting +4, Multiple Casting +4, Obfuscated Casting is much lower than it was before. It still takes a lot of XP, but it is much less than before...(except Multiple casting as per RAW, but that's a huge problem, IMO).
Synthesized Casting
Combines the various mastery abilities into one spell casting. Ordinarily, mastery abilities require a specific method of casting the spell, to take advantage of multiple mastery abilities on the same spell, such as Still and Quiet x2, need to have Synthesized casting of 1. Under RAW Still +Quiet x2 costs 30 xp. Under this modification, Synthesized 5, Still 5, Quiet 15=25, so it is a net benefit.
Ritual Casting
Designed to minimize the risks of a botch of a ritual. This adds half of the ability score to the reduction in botch dice, always at least 1 less botch die.
Mercurian (assisted) Casting
A Mercurian, if he wishes to teach it, can teach techniques for mastery that mimic his methods and use less vis. This doesn't allow a magus to cast a ritual on his own, with less vis, it merely allows the Mercurian to treat anyone with this mastery ability as Mercurian. ((This one needs to be fleshed out, and it's partially based on Paul Briscoe's De Domo Tremeris, but that mastery ability worked for anyone and was a huge end-run around Mercurian Magi))