Counter bug
the opponenet played a card which said put a plus one plus one counter on a creature and then double the amount of counters on that creature. his creature already had two counters on it. so while he played said card i removed those two counters before his card would be played out on the stack. meaning no counters would be on his creature until his card hit the creature which would have left it with one plus one plus one counter on his creature doubling to two counters. this would have made his creature a 4/4 creature in which the creature i had was bigger and would have killed his during an attack. instead of this happening the bug jumped his creature to 8 plus one plus one counters (10/10) as if the counters were not removed. this should not have happened and it cost me the game because his 10/10 was able to kill my creature in the attack instead.