The action game is a video game genre that emphasizes physical challenges, including hand–eye coordination and reaction-time. The genre includes diverse sub-genres such as fighting games, shooter games and platform games which are widely considered the most important action games, though multiplayer online battle arena and some real-time strategy games are also considered to be action games.

In an action game, the player typically controls the protagonist or avatar. The avatar must navigate a level, collecting objects, avoiding obstacles, and battling enemies with various attacks. At the end of a level or group of levels, the player must often defeat a boss enemy that is more challenging and often larger than other enemies. Enemy attacks and obstacles deplete the avatar's health and lives, and the player receives a Game over when they run out of lives. Alternatively, the player wins the game by finishing a sequence of levels. But some action games, usually arcade games, are unbeatable and have an indefinite number of levels; and the player's only goal is to maximize their score by collecting objects and defeating enemies.