I understand how this rule works (of course correct me if I'm just talking nonsense), I'm just wondering if anybody knows how long this particular rule has been around? Has it been around since or near the beginning of the game or was it perhaps a rule update/change later? Looking for as precise of a date as possible with a source of this information if possible. The oldest mentioning of it I can find is from 2009 (google, yahoo, etc searches). Trying to prove to a stubborn player that I can declare a blocker and then tap it to use it's ability while still being able to block the chosen creature. All this house rules BS is starting to piss me off. Why play a game if you're just gonna arbitrarily change or ignore the rules?!
506.4b Tapping or untapping a creature that’s already been declared as an attacker or blocker doesn’t remove it from combat and doesn’t prevent its combat damage.
506.4b Tapping or untapping a creature that’s already been declared as an attacker or blocker doesn’t remove it from combat and doesn’t prevent its combat damage.