Computer and Video Gaming Standards in the USA

The Entertainment Software Rating Board (ESRB) is responsible for assigning and enforcing advertising guidelines adopted by the industry. ESRB judges game content using standards similar to the motion picture industry. The ESRB cares about age appropriate content and privacy.
Ratings
Early Childhood (eC) - Games contain no violence, sexual indications, nudity or questionable language and may be educational.
Everyone (E) Games may contain mild cartoon or fantasy violence. Humor, language, mischief and suggestive indications are all very mild.
Everyone 10+ (E10+) Games are unsuitable for children not yet 10 years old. Games include the same considerations as (E) however, may also include animated or mild displays of blood.Teen (T) Games are inappropriate for children not yet 13 years old. Game content contains moderate to strong presentations of violence, blood and gore, gambling, crude or suggestive humor and suggestive or sexual themes. Partial nudity and strong language may be present.
Mature 17+ (M) Games contain content unsuitable for people not yet 17 years old. Consumers must be 17 or older to purchase the game. Content is perceived to have a strong influence. Blood and gore may be more visible than in the (T) rating. Mature humor, increased gambling, intense violence, blatant sexuality or content, nudity and strong language are present.
Adults Only 18+ (AO) Game content is unsuitable for individuals who have not been recognized as adults by legislation. In the USA, people age 18 or older are adults. Consumers must be 18 or older to purchase the game. These games include blatant presentations of sexuality, graphic nudity, chemical use and or abuse, strong language and mature humor, real gambling, strong violence, blood and gore. AO games are controversial and game developers must often tone down the game in order to obtain licensing, publishing and manufacturer contracts.