Mixed martial arts (or MMA) was a full-contact combat sport that combined aspects of boxing, kickboxing, wrestling, and other fighting styles.
The sport was originally conceived in Brazil, where it had gone by the name vale tudo, or "anything goes." In the 1990s it migrated north to the United States, where for the first few years it was known as no-holds-barred fighting. Eventually, promoters began the process of sanitizing the sport for an American audience and touted the "mixed martial arts" moniker. In time, MMA grew into a multi-million dollar business. Events like the Extreme Fight and the Professional Reality Fighting championships drew crowds of thousands.
Matches typically lasted for up to three five-minute rounds. Barring a few ground rules from the referee, such as no head or groin strikes, fighters were allowed to use both striking and grappling moves, even after their opponent was down. (Chaos Theory)