I'd basicly play it like that, too. Only, when you think about it three dimentionaly, the shield only covers 9 of 26 possible 5'x5' cubes around the caster. Because a tumble could be over, under or around someone, I'd only give it a 1/3 chance of working, myself.the Jester said:It will apply vs. the grapple aoo, but the tumbling through a square issue is a little less clear. When you're in the same square as someone else, who can say which side of them you're on? And since shield only blocks attacks from half the battlefield, this question becomes relevent...
I guess I'd roll d% in that case, with a 50/50 chance of it applying or not.