This article examines and defends the claim that whether or not to cheat can be a genuine moral dilemma within the ethics of team sports. That is, although there is always something morally wrong in cheating there may also be moral reasons in its favour and thus some (and perhaps an overriding) duty to cheat. This is based on the duty that players have of not letting down their teammates by failing to make sufficient effort to achieve victory. In considering the normative limits to such efforts, it is argued that players could reasonably be morally criticised for not cheating where this is of a kind commonly practised in their sport. Evidence is found in the attitudes to cheating of those connected with sport to suggest that some of it is regarded as part of the game, though in a sense that does not undermine its status as genuine cheating. In conclusion a brief consideration is given to the implications for the education, training and character of players, given a belief in there being moral reasons for cheating.