Mixed Martial Arts (MMA) is a full contact combat sport that allows a wide variety of fighting techniques, from a mixture of martial arts traditions and non-traditions, to be used in competitions. The rules allow the use of striking and grappling techniques, both while standing and on the ground. Such competitions allow martial artists of different backgrounds to compete.

In the late 1960s to early 1970s the concept of combining the elements of multiple martial arts had was popularized in America by Bruce Lee via his system and philosophy of Jeet Kune Do, in which he took the best and most pratical techniques from various martial arts an incorporated them into his system, while he discarded techniques that were not effective.

The history of modern MMA competition can be traced to mixed style contests throughout Europe, Japan and the Pacific Rim during the early 1900s; the Gracie family's vale tudo martial arts tournaments in Brazil starting in the 1920s; and early mixed martial arts matches (known as Kakutougi in Japan) hosted by Antonio Inoki in Japan in the 1970s. The sport gained international exposure and widespread publicity in the United States in 1993, when Brazilian Jiu-Jitsu fighter Royce Gracie handily won the first Ultimate Fighting Championship tournament, subduing three challengers in just five minutes, sparking a revolution in the martial arts. Meanwhile in Japan the continued interest in the sport resulted in the creation of the Pride Fighting Championships in 1997. The movement that led to the creation of the UFC, and Pride was rooted in two interconnected subcultures. First were the vale tudo events in Brazil, followed by the Japanese shoot wrestling shows. Vale tudo began in the 1920s with the "Gracie challenge" issued by Carlos Gracie and Hélio Gracie and upheld later on by descendants of the Gracie family. In Japan in the 1970s, a series of mixed martial arts matches were hosted by Antonio Inoki, a former star of New Japan Pro Wrestling; this inspired the shoot-style movement in Japanese professional wrestling, which eventually led to the formation of the first mixed martial arts organizations, such as Shooto, which was formed in 1985.

The sport reached a new peak of popularity in North America in the December 2006 rematch between then UFC light heavyweight champion Chuck Liddell and former champion Tito Ortiz, rivaling the PPV sales of some of the biggest boxing events of all time and helping the UFC's 2006 PPV gross surpass that of any promotion in PPV history. In 2007, Zuffa LLC, the owners of the UFC MMA promotion, bought Japanese rival MMA brand Pride FC, merging the contracted fighters under one promotion and drawing comparisons to the consolidation that occurred in other sports, such as the AFL-NFL Merger in American football.

As competitions became more and more common, those with a base in striking became more competitive as they acquainted themselves with takedowns and submission holds, leading to notable upsets against the then dominant grapplers. Subsequently, those from the varying grappling styles added striking techniques to their arsenal. This overall development of increased cross-training resulted in the fighters becoming increasingly multi-dimensional and well-rounded in their skills.

Victory in a match is normally gained either by the judges' decision after an allotted amount of time has elapsed, a stoppage by the referee (for example if a competitor can not defend himself intelligently) or the fight doctor (due to an injury), a submission, by a competitor's cornerman throwing in the towel, or by knockout or technical knockout (TKO).

Knockout (KO): as soon as a fighter becomes unconscious due to strikes, his opponent is declared the winner. As MMA rules allow ground fighting, the fight is stopped to prevent further injury to an unconscious fighter.

Submission: a fighter may admit defeat during a match by:

* a tap on the opponent's body or mat/floor
* a verbal announcement/ verbal tap

Referee stoppage: The ref may stop a match in progress if:
- a fighter becomes dominant to the point where the opponent can not intelligently defend himself and is taking a lot of damage
- a fighter appears to be unconscious from a submission hold or due to a strike
- a fighter appears to have a significant injury such as a cut or a broken bone

Doctor Stoppage: the referee will call for a time out if a fighter's ability to continue is in question as a result of apparent injuries, such as a large cut. The ring doctor will inspect the fighter and stop the match if the fighter is deemed unable to continue safely, rendering the opponent the winner. However, if the match is stopped as a result of an injury from illegal actions by the opponent, either a disqualification or no contest will be issued instead.

Corner stoppage: a fighter's corner men may announce defeat on the fighter's behalf by throwing in the towel during the match in progress or between rounds.

Decision: if the match goes the distance, then the outcome of the bout is determined by three judges. The judging criteria are organization-specific.

Forfeit: a fighter or his representative may forfeit a match prior to the beginning of the match, thereby losing the match.

Disqualification: a "warning" will be given when a fighter commits a foul or illegal action or does not follow the referee's instruction. Three warnings will result in a disqualification. Moreover, if a fighter is injured and unable to continue due to a deliberate illegal technique from his opponent, the opponent will be disqualified.

No Contest: in the event that both fighters commit a violation of the rules, or a fighter is unable to continue due to an injury from an accidental illegal technique, the match will be declared a "No Contest".