Like the title says, receiving duplicate items is annoying. Receiving Cicero and Gilgamesh shaders after every other match is annoying. Perhaps an 'if' function that reads the players inventory real quick and removes items a player already owns from the list of possible rewards. It could go a long way to encouraging replay; because as it stands receiving junk for rewards sucks but getting the same junk over and over is even more disheartening.