The following is a list of video games that have been given the "Adults Only" rating by the Entertainment Software Rating Board, a United States-based organization which rates the content of video games to determine its appropriateness for specific age groups. Although it is not legally binding under U.S. law, the ESRB rating system is a de facto standard which is self-enforced by the U.S. video game and retail industries. In some Canadian provinces, ESRB ratings are enforceable by law by localfilm classification boards. Games with the AO rating are considered by the board to be suitable for players age 18 and over; AO-rated games can contain higher levels of violent, profane, sexual, or pornographic content than the next-lowest rating on the scale can accommodate. AO is the highest of the ESRB's content ratings, and restricts the commercial availability of games which carry it; all three major video game console manufacturers refuse to allow AO-rated games to be published for their platforms, most retailers refuse to stock AO-rated games, and the popular video game live streaming service Twitch explicitly bans all games carrying the rating. The only mainstream platform to allow AO-rated games is Steam, which hides them by default. Due to these self-imposed restrictions on the marketing and distribution of games with the rating, the AO rating has been described as a "kiss of death" by critics, and is essentially a ban. Relatively few games carry the AO-rating; the majority of AO-rated games are adult video games which received the rating for containing sexual and/or pornographic content, but the ESRB has also issued the rating for games containing extreme violence. The fighting gameThrill Kill was given an AO rating for its violent content; its release was cancelled after the acquisition of its publisher, Virgin Interactive, by Electronic Arts, as they objected to the game's content. Rockstar Games' Manhunt 2 was the second game given an AO rating for extremely violent content and the first to be released, but was re-edited to meet the M rating so it could be released on consoles. Hatred, a game centering on a character indiscriminately murdering everyone he encounters, was the third game to receive the rating solely for violence and the second to be released. The only game to receive the rating for reasons unrelated to violence or sexual content is Peak Entertainment Casinos, which received the rating as it allows the player to gamble using real money. Fellow Rockstar game was temporarily re-rated to AO from M in response to the release of a mod known as "Hot Coffee", which allowed players to access a sexually-explicit minigame that was removed in development, but still present within the game's code in an incomplete state. The M rating was reinstated after Rockstar released patches and revisions of the game which excluded the content entirely. San Andreas remains the only mass-released AO game.
