Would it be possible to quicken a Control Thoughts spell on someone? What kind of control would it give the caster?

since you can quicken any sustained spell. i'd say yes.
everything. provided that you are alway around and the person doesn't break the spell.

If you're ABSOLUTELY sure that he can never break the spell, then the Control Thoughts Quickened would work fine. But be sure that he will NEVER resist, because it only takes 1 time and the Karma is lost. Unlike most other spells, this spell has rules for 'breaking' the spell. And remember, if the caster is not present when an unwilling-to-do thought is controlled (shoot the dragon when you see it) it only takes 1 success (this is not resisted) against the Force of the spell to break it.

Sphynx

I question the intelligence of anyone who quickens a Control Thoughts spell on someone so that he can make them shoot at dragons (but hey, find a Dragonslayer idolist...).

I guess it would depend on what the GM considers a person to be "deeply opposed" to. Violent acts would be opposed, certainly, but usually a person uses Control Thoughts to circumvent a violent solution to a problem.

Speaking of opposing, would Control Thoughts be allowed to provide 'justification' to a prompted action? "Hey, that guy just cut you off! Give him the finger and honk your horn!" "Violence erupted in the Seattle streets today during a road rage incident involving known mafioso Lenny 'Honk At Me And Die, Fragger!' Carlioni...."

you may want to use the social situation "players desired result" mods sr3 p94 as an example for target numbers to break the spell. just reverse the +/- and subtract from the force.

It'd probably work great if you quickened Decrease Willpower as well.

The trouble is, quickening spells is like putting your signature on them. Not the best idea for a deniable mind-controlled asset - old-fashioned brainwashing would be less traceable. Plus, you can't drop the spell, so if that person ever gets caught by anyone capable of assensing, the game will be up. Plus, if you just give the person some commands and turn him loose, he might be able to come up with a clever way to communicate his predicament or otherwise screw things up for you. The control thoughts spell is best when closely supervised - anything less gives the target a chance to circumvent his orders.

There's also the fact that Control Thoughts tends to be an 'interactive' spell in that the caster chooses the overriding thoughts for the target on pretty much a real time basis. I'd say if Quickened and then left alone the target's normal thought processes would resume, but the caster could take the "captain's chair" again any time the target was in line of sight so long as the spell remained quickened. If you want to permanently screw with someone's thoughts then make good use of the Influence and Alter Memory spells. You can also clear up your spell signature after the casting and there's no nasty little astral trails back to you.

Remember what happened last time you started slinging the Control Thoughts spell, though.

~J