I do think it would be cool if two players decided to play “combat tandem” and have a medium sized creature provide cover for a small creature. The tank sees the enemy using ranged attacks and says, “Hey! Halfling Rogue! Get behind me and attack those suckers! I’ll wait for them to get closer!”

That would be awesome.

“Creatures and Cover: When you make a ranged attack against an enemy and other enemies are the way, your target has cover. Your allies never grant cover to your enemies, and neither allies nor enemies give cover against melee, close, or area attacks.”

We know that allies never grant cover to your enemies, so we can assume that it’s not the fact that there’s a creature in the square that’s granting the cover … it’s something to do with the creature’s allegiance and intent. So a body standing there doesn’t actually grant cover, in and of itself.

Now notice that the rules only stipulate that your target has cover WHEN YOU MAKE A RANGED ATTACK. So it’s as if you, as the target, suddenly have a split second of cover and could make a stealth check … if only you were taking an action. But you’re not, so it’s moot for the purposes of combat advantage. As soon as the ranged attack is complete, your cover is also gone, and so is your opportunity to make a stealth check.

Another way of looking at it is that the ally, as a free action possible only when you’re being attacked at range, is choosing to give you cover against that precise attack.

In the game system, I think that keeps things much easier but doesn’t harm the rogue’s power level much. And if a rogue has a way to make a stealth check as an interrupt, or even a stealth check and an attack as an interrupt, they could absolutely get combat advantage for that interrupting attack … they deserve it, after all of that effort!

Thanks for your efforts toward an easy-to-understand interp.

Anyway.

Sounds like about the only chink in the game logic is say…

(rogue) (defender) (minion with a longspear)

In this case, the rogue makes a stealth check. The minion cannot see the rogue, because the defender gives cover. Rogue is hidden from view.

Minion’s turn. He goes to attack with the longspear, which gives him reach. Because this is a melee attack, the rogue does not have cover, therefore is not hidden… so now he is visible? And after the attack, does the rogue go back to being hidden, since the minion no longer has reach, therefore the rogue has cover again, therefore the old stealth check stands?