For questions generally relating to strategies, tactics, player positions and/or special teams intended to prevent an opposing player or team gaining standing in a game relative to one's self or team. Questions using this tag should also be tagged with the specific sport in question.

In many sports that allow direct interaction between competitors, preventing the opposing player or team from scoring points is often at least as important as scoring points. The area of the game in which the players attempt to do this is known as their "defense". Depending on the sport, various defensive strategies have arisen, often with multiple strategies and tactics available as specific counters to an opposing team's style of offensive play. A team's "defense" typically ranges in scope from team composition to player formations to tactics and individual technique.

In some sports, there is a distinction made between a style of defense in which each player is responsible for covering all action within a certain portion of the play area, and styles in which each player is responsible for shadowing a specific opposing player. These two opposing styles are known as "zone defense" and "man defense" respectively. Each has strengths and weaknesses depending on the game, the players and the opposing offensive strategy.

In some sports only one such strategy is viable (soccer defense is more or less zone-based; defenders challenge any player with the ball in their area of the field), while in others these are more or less the same thing (Basic ice hockey strategy, for instance, typically involves a rough "X" formation for both sides, with defensemen covering forwards and centers covering each other as they move up and down the rink), while in others the distinction is nonsensical (baseball fielding can be thought of as a "zone defense", but there is no possible option for "man defense", as not all of the batting team's players can ever be on the field at once).