As far as I know, it's not illegal in football (soccer) to kick the ball really hard at someone's face if they are in the way of goal. Throwing dummies and gamesmanship are also treated as acceptable. So how exactly does agreeing on rules of a game remove normal moral constraints? I know people wouldn't be happy if I started blasting a football at their faces, but would it be morally ok?

Boxing is an even more obvious example of a rule-governed sport that involves what would otherwise be immoral actions. The answer usually given lies in the notion of consent. By agreeing to be a part of the game, one consents to be subjected to such actions; and, equally, is given the right to commit them. There are some actions in sport that are not part of the rules. Players have been subject to criminal prosecution for particularly violent tackles during a professional game.

The notion of consent, however, is not universally accepted. For example, suppose it is the case that forms of violence in sport feeds a culture of the acceptance of violence outside the sport (among viewers or participants). This is a question for empirical sociology or psychology, but the implications of the answer are ethical. In that case, consent within the sport may mean that one is consenting to more than one has the right to consent to; one is consenting on another's behalf, or even that consent takes away the possibility of the consent of another. Then there may be good reasons for claiming that such violence is morally wrong. A similar argument is often employed concerning the morality of pornography.

It's not illegal but practitioners of the game would certainly be judged to be immoral if it was done with the intention of hurting someone. It is true though that we can do things in sports that would be judged to be immoral in other contexts and on this point I agree with Douglas Burnham that it is a matter of giving consent - accepting the rules of the game.

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