Quicken Spell Negating AoOs? (Mage Slayer)

[Kevingway]

I remember reading somewhere that if a spell is pushed to being a Swift/Free Action in some way, it negates the Attack of Opportunity that would normally be provoked by casting in a threatened square. Where might this information be found, if it exists?

Also, I'm trying to perfectly visualize how a Mage Slayer scenario would play out (partially because I barely ever play casters). Someone casts in my threatened square, since they can't move due to Stand Still and they know they can't cast defensively. I hit them, and... what is it? They have to make a Concentration check with a DC = to the damage done, I think, or lose the casting? It's a silly question to ask, but I really can't remember where to find the rules anymore (maybe because it's 1:20 in the morning).

And on that note, does anybody have any advice for a build like this, maybe getting it to apply to Psionics and not just other casters (Psionics-Magic Transparency not applying to feats, and all), and figuring out other ways to beef up a caster lockdown build?

[Deox]

Relevant text from SRD:


Metamagic feats that eliminate components of a spell don’t eliminate the attack of opportunity provoked by casting a spell while threatened. However, casting a spell modified by Quicken Spell does not provoke an attack of opportunity.

And if the caster is damaged while trying to cast a spell, the concentration DC is 10+ damage dealt.

As far as a build idea, Occult Slayer is usually a solid choice to work in. Throw in Hexblade, maybe Paladin of Tyranny and you can have some very solid defenses. Defensive Sweep, Stand Still, Knockdown for some feats.

I've seen some builds utilize Suel Arcanamach and Witch Slayer to frightening effect.

[Gwendol]

Knight 4 to get Bulwark of Defence. That way the pencil-necked buggers can't 5' step out of your threat zone before casting.

[animewatcha]

There is a feat in one of the dragon mags that, amongst other things, negates the quicken spell AoO protection. If you pair it with mage slayer, the caster has to cast the quicken spell on the defensive.