[PhilD]

Originally posted by PDF:
Wait wait wait ! You mean that every slave takes fatigue as if he was himself casting the spell ?

I'm pretty sure that's what I saw explained somewhere. The slaves will take fatigue based on their own level (not augmented if they don't have the required level, fortunately).

I understood that the fatigue was calculated for the casting mage (incl "extra levels" for communion), then divided..
In your case the total fatigue is 89*8+30 = 742, not much less than the base 800, and more than if the mage alone cast it (he will get 400). In this case he wouldn't be able to cast it, but the reasoning still stands for less fatiguing spells...

Basically, the Communion lets you cast more powerful spells, AND spread the fatigue around for high-fatigue spells. The more slaves, the better, especially if your slaves have some reinvigoration (which is why having a Master cast some reinvigoration is a good idea, or should be).

Keep in mind, though, that I have very little experience playing with communions. You're the one playing Pythium in a MP game...