Frankly, I can't understand people who complain about Spell Mastery being too powerful. "Oh no, you can do x3 to the concussion damage on your bolts" by rolling an Extremely Hard maneuver on a pretty nasty table (Power Man, a partial success = take 10 concussion hits and fail your effect) of which if you fail will also probably trigger a spell failure (if not two). The skill starts at -20 to even do something, and anything below Near Success will yield horrible results, with Near Success being a "try again if you dare" kind of result. Thus, anyone even attempting the most basic use of the skill on a routine basis has to be highly skilled or willing to risk dying a horrible death. At the level a spell user tries the x3 without risking too much(5% chance of failure on a -30 roll where you want at least Near Success requires 115 in the skill...), a fighter might end up constantly hasted, thus attacking twice per round at full OB with his +25 weapon that does triple concussion and an extra elemental critical.
And frankly, if a spell user wants to use the x3 range to save power points by casting Firebolt I rather than Firebolt III, be my guess... You have to make both your Power Manip roll and your spell casting roll, with the above-mentionned risks. I hardly find that unbalanced.
I agree, but I changed the skills mainly for 2 reasons:
1) When player has high bonus, it wants to use it many times, and it slows the game.
2) It is a very 'step' skill, this is, or nothing or great power/fumble. And we need a good bonus as the first maneuver is at -20 directly.
For that I changed it to use the bonus as % for increase parameters (split as parry between all effects), only requiring SCSM for casting the spell, but not a maneuver roll (this one is used for other effects but not for parameter increase) and it doesn't takes 1 minute.
This rule allows to use the skill faster, from beginning and more linear, i.e. a cleric with +25 in SM can 'bless' with +25% radius (12,5' instead 10'), you could cast a 'bolt' increasing the damage a portion and no need for many rolls (a 10B result would be 15B if +50 in SM skill bonus).
I like in this manner because I see this skill as "how good are you casting spells for that list", so it should be used in this linear way.
And the SCSM can be easily passed developing some 'magical language' ranks, that added to your list bonus and a +1 per SM rank I use for this rule, we have that is all like specialize in spell lists with SM, but not in the sharp way the original skill.
So I see the spell list as the 'basic form' and then the spell user can improve it as it desires. You can have +25 in one list, +50 in other and +100 (or more) in your favorites.
With the SCSM requirement we are using the spell casting like in HARP, where you always must roll a casting maneuver roll (if I am not wrong), so if you want to haste the game there are rules for include all in 1 roll (the casting maneuver and the attack spell directly in 1 roll).