Invisibility... how do you handle it ?

[Dimwhit]

But for example when an invisible mage fires off magic missiles or a fireball... it should be easier to point the general area he is in than if he is just running around...

Not necessarily. The Wizard could cast fireball or magic missile, then move his full movement. They may know where the spell came from, but the Wizard could be anywhere after that. (I assume we're talking about Improved Invisibility at this point...)

 

[Quidam]

opposed checks

Does anyone allow for an opposed Move Silently roll from the invisible one if you're allowing passive Listen checks for the detectors?

 

[Darklone]

Re: opposed checks

Does anyone allow for an opposed Move Silently roll from the invisible one if you're allowing passive Listen checks for the detectors?

I ask for it, yes. But noticing someone does not mean you know where he is.