No dice roll required. As long as you meet the requirements (one hand free, not already done it this round) it works.
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I can't speak for specific modules or any home game, but I've found running PFS scenario's they really don't send a lot of skilled archers at you. Most of the time it's martial opponents that just try to toss arrows/bolts at range until your melee close distance, and they're not at very high BAB even then.
Even when you do use it, as soon as you use it once your opponent is likely to just pick another target unless you're clearly the only immediate threat.
So when it's needed it certainly is powerful, it's still situational enough that many times you just won't use it.
And at higher level, archers can fire lots of arrows per round, so blocking one of them isn't that effective.
At BAB 6, archers are putting out 4 arrows a round. 1st attack, iterative, rapid shot, manyshot. Being able to block only 1 of those and requiring you to have a free hand to do so is actually pretty well balanced.
Truthfully, it's rare for NPCs to use ranged weapons anyways compared to the number of melee combatants...so I don't really see it as much of a problem.