New mastery abilities

Criticize and/or add your own!

Cautious casting: The magus is treated as having the Cautious Caster Virtue while casting the spell.

Reckless casting: The caster can choose to boost the spell one magnitude in puissance, with the Storyguide determining the exact effect as per Wizard's Boost (this effect can be stacked with that of a Wizard's Boost). If he does, however, he also rolls twice the usual number of botch dice, with a minimum of three botch dice, after all other modifiers to botch dice have been applied.

Parsimonious casting: The ability can only be taken once for a given spell, which must be a Ritual and can then be cast using one less pawn than normal.

Teaching insight: The magus is treated as having the Good Teacher Virtue when teaching or writing about the mastery ability. When teaching the spell itself, only half its level is counted for the purpose of determining how many spells the student can learn during a season.

Special Circumstances: The spell benefits from a casting bonus of +3 under a special set of circumstances. These must be no more common than those of the "Special Circumstances" Virtue in relation to the spell (e.g. one cannot designate "when touching the target" as a Special Circumstance for a R:Touch spell). The bonus provided by the Mastery Ability is not cumulative with that provided by the Virtue. Like in the case of the Virtue, this ability can be chosen multiple times, each time selecting a different set of circumstances; if multiple sets of circumstances apply to the same casting, the caster benefits from a single +3 bonus.

Theoretical underpinnings: When casting a similar spell spontaneously, the caster adds his Mastery score to the Casting Total. A spontaneous spell can benefit from only one such bonus at a time. (Note: this rings all my alarm bells about potential abuse, but I haven't found a concrete case).

Communal casting: When casting this spell in a Wizard's communion, the caster subtracts one botch die for each participant, to a maximum of his Mastery score (eliminating the corresponding die added via the Communion).

Tailored casting: When choosing this ability, the magus selects a number of valid targets for the spell equal to his Mastery score, and can subsequently add one more target whenever his Mastery score increases by one. The spell is treated as specifically tailored to any of these targets for the purpose of determining Warping.

Experimentation. The magus explores uncharted ground about the possibilities of the spell. When selecting this ability, roll on the Extraordinary Results chart, treating the number of times this mastery ability has been selected as the Risk modifier (the ability can be selected a maximum of three times).
Disaster: the magus score in the Mastery ability drops by 1 (the "Experimentation" ability is lost as a result in the process).
No extraordinary effects: the magus must select another mastery ability.
No benefit: the Experimentation ability does nothing (but still "wastes" the special ability tied to this level of Mastery)
Side effect or Modified Effect: The magus learns how to cast a variant of the spell, determined according to the Side effect/Modified effect subtables (it is effectively the same spell, so the Mastery score and abilities apply to both variants). The magus retains the ability to cast the unmodified spell.
Discovery or Special/Story Event: as per the standard Experimentation results.

I think cautious casting as described is extremely powerful. Consider that it subtracts four botch dice by taking it, which is huge. It would be the obvious choice for the first mastery ability for a ritual spell. I'd instead make it as a point per point deduction, and it must be taken multiple times like precise and quick casting. It's still pretty good, each point of mastery in this ability is effectively double counted for botch dice reduction.

I wouldn't object to Parsimonious casting taking more than one pawn of vis off, just take it multiple times in the style of quick or precise casting, maybe the limit of vis reduction is up to 1/2 the vis of the spell. There is certainly an element of diminishing returns of xp for each pawn of vis removed. Granted, it also effectively doubles the subtraction in botch dice.

For teaching insight, what happens when the teacher already has Good Teacher? How about instead of making it as Good Teacher, why not increase the SQ by the mastery score. For those who are true subject matter experts in this spell, with mastery of 6 or more, it's better than Good Teacher (and I'm ok with this, as it's very narrow). I don't think it should count less for level of spells taught in a season, since those limits are a function of the teacher's and student's TeFo...

Theoretical underpinnings I would treat as precise and quick casting, it would alleviate your power concerns, and it would reduce its power as compared for Faerie Raised magic, a bit.

I don't understand tailored casting, and how it's different from multiple casting.

My own thoughts are forthcoming, but first...

@JL: Tailored casting refers to the fact that you can design a spell for an individual, and it's treated as if that person were the caster for Warping. Tailored Casting is thus only useful for spells higher than level 30.

My suggestion: (Requires base assumptions about combat rounds being 6 seconds long, though it's adjustable to any length)

[code]Channeled casting: Rather than casting immediately, the maga focuses her magic, adding more power to the spell being cast. Every combat round or 6 seconds when not in combat, the player makes a stamina + concentration roll which starts at a target number of 3 for the first roll and increases by 3 every round. For each round the character passes this roll, increase the casting total by the character's stamina. The spell is cast either when the caster fails this concentration check, or when the caster consciously chooses to release the spell.

Example: Miranda of Jerbiton has Concentration 4 and Stamina 3. She has a base casting total of 14 for a level 5 version of Demon's Eternal Oblivion. She has this spell mastered with Channeled casting. She is facing a might 15 demon, and thus needs 16+ penetration.
Miranda's player rolls for the casting total, and gets a 4. This gives her a total of 18 for the casting total. Subtracting the level of the DEO, she has a total of 13 penetration thus far. At the start of the second round of combat, she rolls for her concentration + stamina roll, against a target of 3. With 4 concentration and 3 stamina, she passes as long as she doesn't botch. This increases the casting total by 3, resulting in the penetration being 16. This is enough to penetrate the demon's might.

If she were facing a might 25 demon, she would have had to maintain concentration on the channeling, and survive for 5 rounds in order to have a penetration total of 26+.

Channeled casting is incompatible with ceremonial casting, and cannot be taken for Ritual spells.[/code]

Might be a wee bit weak, in which case suggestions to tweak it to make it on par with the others would be appreciated... (I was considering the addition to the casting total being stamina+number of rounds channeled. In which case the longer you can hold it the more valuable it is. That would drop the second example's channel time to 3 rounds instead of 5.)

Hm... I'm not sure I like that ability, not for being over- or underpowered, but because it implies too much in-character knowledge about the exact amount of power the character is channeling, especially for something to be done during combat. The player can tell that their Penetration is exactly 19 so they need to add their Stamina once for a 21 to overcome the demon's 20 (just as an example), but I feel like that's just a tad too intimate a mechanic to be judging what the character will do based on it.

Channeling should probably cost fatigue if the spell doesn't penetrate, and if the concentration check fails.
Akriloth, characters don't necessarily know the might of creatures they face. And thanks for pointing out tailoring, I'm not sure how I missed that. I have reading problems, obviously...

You're quite welcome. It happens to the best of us.

And that bit about them not knowing the Might only supports my point further. Knowing exact Penetration totals and Might scores and such is fine for players and makes the system possible to adjudicate, but that particular ability hinges too much on assuming that the characters have access to the same numerically precise knowledge, and can think it up on the fly in the middle of something as hectic and dangerous as a fight.

Well, you channel, trying to penetrate, and if you fail to penetrate, then it costs fatigue. You make an estimate, as a player, and it costs the character something...

I'd argue a magus knows approximately how much power they are putting into their spell. After all, at the very worst, they have an approximate idea what their arts are, power wise... (Not numericly, but instinctively. Numerics is how it's represented for players).

After all, otherwise how does a magus know what they need to get the bonuses for Study Bonus or Study Requirement? They have to at least be able to judge the magnitude of the power for that reason.

This comment suggested a simple resolution to me: Don't make your casting roll until the spell is released.

In-game, this reflects that you're not actually done casting until the spell is released, so don't roll a casting total until then.

Out-of-game, it forces players to make an estimate of how long they need to channel without the precise numerical knowledge of "my penetration is currently 19", since the penetration hasn't been determined yet.

Regarding it costing the character something, I think an automatic fatigue level sounds appropriate if the spell "escapes" early due to a failed concentration check, but moving the casting roll to the end of the process also allows for the number of rounds spent channeling to increase the number of botch dice if a 0 is rolled. One extra botch die per round seems a bit overly harsh, but maybe a pyramid progression, with botch dice added after 1/3/6/10/etc. rounds, would work. These extra botch dice would, of course, be offset by mastery itself, but I think I would also rule that channeling is inherently stressful and can always botch unless mastery or virtues eliminate all botch dice.

Channelling is already costing something :time.

The only change I'd make is that any target of such starts experiencing pings off their MR the moment the channelling starts; basically forewarning that something big is incoming. This means the cost (the additional rounds) always matters in any scenario where the target can actually retaliate.

Maybe it doesn't ping on MR, because the effect hasn't been delivered until the caster is finished channeling. It should be a simple awareness check to determine if a caster is channeling something, though. It gets harder if no gestures or obvious hermetic incantations are being made.
Time doesn't mean a lot, though. I mean grogs might be going down while the magus is getting his stuff together, but that's what they are there.

Because of the pyramidal experience system, mastery becomes really difficult, and if your saga doesn't subscribe to the view that mastery texts are easily and commonly available then it can be something of a challenge to improve spell mastery beyond a score of 3. It can be done, but it gets much harder. So, I've thought of certain mastery abilities that unlock after a certain mastery level. If ezzelino's cautious casting were kept with a reduction of 3 (effectively 4) botch dice, I'd put the level it can be learned as 5, too. I have some issues with this minimum ability level requirement. It seems gimmicky, and almost like feats. I dunno.

Deft Casting allows the caster to cast it without using voice or gestures. This mastery ability may only be purchased after the mastery ability has reached a score of 5, requiring a deep knowledge of the spell's construction to be able to modify it so.

So, a magus has a score of 5 in a spell mastery ability and has never had the chance to implement quiet casting x2 or still casting. Presuming those mastery abilities are taken immediately, the minimum cost for acquiring "deft" casting is 30 xp by taking quiet x2 and still casting. Taking deft casting at an ability score of 5 would cost 30 experience points, the minimum, so there is parity there, and still allows someone who pursued other mastery abilities early on to acquire deft casting. The cost for acquiring quiet x2 and still starting from an ability score of 5 is 105 xp.

Moving the die roll to the end of the channeling period works.

Maybe to beef it up a bit, add the mastery score to the boost?

Add a botch die to the casting roll for each round you channel + 1 for channeling anyway? (So if you try to channel and fail, it's still a stress roll with a single botch die)
Note this makes it a stress roll, which isn't always useful.

Don't think channeling needs to be beefed up, mastery is already part of the casting total, adding it more than once seems a bit strong.

I'd say add your Stamina or the spell's Mastery score. Then it's still useful (but more difficult) to characters without positive Stamina.