Any ideas how to adjudicate how many botch dice to roll with spells gone wrong?
If you used 1 die per magnitude of spell, i imagine you'd see quite a bit of warping points gained.
If that was the case, would make low level spells far less likely to give warping/twilight yes? and thus you can mitigate your risk by keeping to low level spells (which of course penetrate MR more effectively)
Any thoughts?
BBB
The rules for botch dice are on page 7. One botch die as a default for stressful circumstances (formulaic spells can sometimes use a simple die) and more botch dice for increasingly hazardous situations. These rules are complete, everything else is just an elaboration of specifics regarding them. The storyguide should decide, there isn't (and shouldn't be) a comprehensive list.
That said, there are other factors that provide specific numbers of botch dice.
Foreign auras are perhaps the most common and most significant factors to add more.
Spell mastery and the golden cord can remove botch dice
virtues and flaws such as clumsy magic and cautious sorcerer can change things
You get one botch dice per pawn of vis used. This can be a big deal .(I believe that you get more if you use some specific types of vis: infernal and possibly faerie)
I'm sure that there are other explicitly layed out modifiers and hopefully people will post them, but the big deal, bigger than these rules determined factors, is the storyguide who examines the situation and decides that a preponderance of bees, or being out of breath, or the two beers that the magus had for lunch, or the unrelenting judging stare of their mentor, or the fact that the magus spent the last three hours as a frog and hasn't yet had the opportunity to adjust to being human again, or having hay fever, or standing on a sled that is hurtling down an icy but not particularly smooth slope, or being very cold, or being chased by a horde of mongol warriors, or whatever else is happening is worth an extra botch die or two.
Also Divine, if used for neutral or selfish purposes, I think. (If you can get your hands on it - the Holy Magic section in RoP:D talks about mining vis from Divine auras, and what happens if you use it in an not-holy fashion. Serf''s parma, but I think it doubles the number of botch dice you're using.)
Outside of the specific stuff mentioned re: vis, auras, etc... botch dice on spells come from the same sources as botch dice on everything else.
I treat the base botch dice for a formulaic spell as zero - so casting a formulaic spell in the comfort of your own covenant on a fine day without anything untoward going on? No chance of botch. Anything that would logically add to the stress of a situation adds botch dice.
Casting in a combat where time and precision are of the essence? +1 botch dice
Casting while standing on a slippery slope? +1 botch dice
Casting while exposed to a strong wind? +1 botch dice, and possibly some concentration
Casting in pitch blackness without a way of seeing your hands? +1 botch dice
Casting in combat that's pitch black on a slippery slope in the wind while torrential rain is falling and you can hear the approaching baying of supernatural wolves? Probably 5-6 botch dice before you even start factoring in aura and vis.