The Gaming Den

Imagine someone who gets grappled, then successfully casts sanctuary. In normal D&D on further rounds, does an assailant need to make further grapple checks to maintain their hold, which would be stopped by sanctuary and thus the caster is released? If there are no 'maintenance' checks, then the grappler doesn't need to do anything to maintain their hold. However, were the caster to try to break out of a grapple, that's a check which would count as an attack and would thus break the spell's protection.

Am I correct in seeing this as a stalemate between the two where nothing happens until the spell wears off or the grappler actively releases the caster to move onto something else (assuming there's other things to deal with)?

There are actually no maintenance checks. once you're grappled, you're grappled until the other guy lets go or you escape. Now escaping, actually requires an opposed grapple check, but that's not actually an "attack" in the D&D sense.

There's no active actions required to maintain a grapple in 3E.

Now in the event of a sanctuary, the grappler can make no further grapple attacks (such as trying to pin, inflicting damage or stabbing the guy he's grappled with), but he can still opt to release the target and may still make opposed grapple checks to try to keep grappling the target.

The grey area is actually if escaping a grapple counts as an attack (and breaks sanctuary). Regarding that, I'm honestly not sure.

Actually, attempting to escape a grapple is "as an attack action" whereas inflicting unarmed damage is not, so while the grappler could not stab the caster with a knife he could put him in a sleeper hold until he falls over while the caster himself cannot try to get out without provoking the grappler to be able to stab him. with a knife.