bad luck
I had a player who wasn't overly creative. He got a magical mace that was also rather evil, so he shouldn't have been using it. Every time he tried to attack with it he would say, "Pelor guide my mace." and then he would roll a 1. We had a rule that a critical fumble (which he did every time) resulted in you throwing your weapon, so a crit fumb removed that weapon from the battle.
He made 5 attack rolls in 5 battles and rolled a 1 each time. The odds are 1 in 3,200,000. The BBEG threatened to kill him if he didn't give the mace back (as it was the BBEG's) which he gladly did.