League of Legends is a 3D, third-person multiplayer online battle arena (MOBA) game. The game consists of four game modes: Summoner's Rift, Twisted Treeline, Crystal Scar, and Howling Abyss. Players compete in matches, typically lasting 20–60 minutes. In each game mode teams work together to accomplish a terminal objective and achieve a victory condition, either to destroy a central objective controlled by the enemy team, known as a Nexus, or to capture and hold the most strategic points for the longest period of time. Each game mode includes a variety of smaller intermediate objectives that give players and teams advantages in achieving overall victory.
In all game modes players control characters called champions, chosen or assigned every match, who each have a set of unique abilities. Champions begin every match at a low level (level one for Summoner's rift and Twisted Treeline, and level three for Crystal Scar and Howling Abyss), and then gain experience over the course of the match to achieve a maximum level of 18. Gaining champion levels in matches allows players to unlock their champion's special abilities and augment them in a number of ways unique to each character. Players also begin each match with a low amount of gold, and can earn additional gold throughout the match in a variety of ways: by killing non-player characters known as minions and monsters, by killing or helping to kill enemy players, by destroying enemy structures, passively over time, and through unique item interactions or champion abilities. This gold can then be spent throughout the match to buy in-game items that further augment each champion's abilities and game play in a variety of ways. Champion experience, gold earned, and items bought are specific to each match and do not carry over to subsequent matches. Thus, all players begin each match on more-or-less equal footing relative to their opposing team.
Across matches, players also earn rewards that are specific to the individual, and augment matches played. Player experience is earned by playing matches over time on a particular account. Player accounts begin at level one and progress through a maximum level of 30. As a player progresses they unlock various maps and game modes not available to new players, as well as an additional two abilities to be used in matches, known as summoner spells. Players also unlock Runes and Masteries, which can be used to provide small bonuses to a player's champion in battle.
All game modes use automated matchmaking based on the Elo formula, with proprietary adjustments. A player's behaviour is tracked between matches, and players that display poor behavior may be subject to varying sanctions. These are delivered by an automated system, and range from warnings, to chat restriction, to temporary and permanent bans from the game. This system replaced an earlier system, called the Tribunal, which sent game logs to the community to collectively decide whether a player's behaviour was sanctionable. Permanent bans were still reviewed manually.