[Eye Eternal]

Is there a limit to the number of spells a mage can sustain at once without using foci? Can you just eat a ton of negatives and hold many spells at once as sustained? I haven't seen a concrete statement saying no.

[farothel]

As far as I know you can sustain as much spells as you can.  Of course, given that every spell you sustain without a focus gives a -2 penalty to all other actions, the absolute maximum is (magic+spellcasting+edge)/2, as you can't cast more spells if that dicepool has reached 0.

[Eye Eternal]

That was what I had figured. (Minus the edge part, I didn't think of that) I would assume its safe to say the same would apply to TM and threading then, seeing how it states a threaded complex form requires sustaining as well. Thanks a lot for the info.

[Netzgeist]

And if you want to push the limits a little bit farther, Psyche (SR4A, pg. 258) is your chemical best friend - turning that pesky -2 into a much less annoying -1.

[Dr. Meatgrinder]

As far as I know you can sustain as much spells as you can.  Of course, given that every spell you sustain without a focus gives a -2 penalty to all other actions, the absolute maximum is (magic+spellcasting+edge)/2, as you can't cast more spells if that dicepool has reached 0.

Maybe (Magic+Spellcasting dice pool)/2 (or /1 if you've popped Psyche) + Edge, since you can spend each point of Edge to make a Long Shot Test (p. 61, SR4A), using just Edge in place of a zero dice pool.  By that time, though, you're not likely to affect many unwilling targets.

In practice, I haven't seen more than two being sustained at any given time outside of sustaining foci.