Basic Objective
The goal of MMA is to defeat your opponent by any legal means. This can happen through striking (hitting), grappling (wrestling and submissions), or earning more points than your opponent over the course of the match. A fighter wins by knockout if their opponent cannot continue, by submission if their opponent taps out or cannot escape a hold, or by decision if the judges score more points for one fighter.
Striking Rules
Fighters can punch and kick most parts of the body, but certain strikes are forbidden for safety. Illegal strikes include hits to the back of the head, groin shots, and strikes to the spine. Fighters must wear padded gloves that cover the knuckles to reduce injury. Head kicks, body kicks, and leg kicks are all legal techniques used to damage or slow down opponents.
Grappling and Submissions
Fighters can take their opponent down to the ground and use wrestling techniques. On the ground, fighters can attempt submissions, which are holds that force their opponent to surrender by tapping. Common submissions include chokeholds and joint locks that target the arms or legs. Some submissions are illegal depending on a fighter's experience level to prevent serious injuries to younger or less experienced fighters.
Fouls and Illegal Moves
MMA has strict rules about illegal techniques to keep fighters safe. Banned moves include eye gouging, biting, hair pulling, headbutts, and strikes to the groin. Slamming from certain positions is illegal, as is grabbing the fence of the cage. If a fighter commits a foul, the referee may deduct points, pause the action, or stop the match entirely depending on the severity.
Scoring and Judging
If a fight goes the distance without a knockout or submission, three judges score the match using a 10-point system. The winner of each round typically gets 10 points, while the loser gets 9 points or fewer depending on the damage and control shown. Judges look at striking effectiveness, grappling control, aggression, and defense. The fighter with the most points after all rounds wins by decision.
Safety and Stoppages
The referee can stop a fight if a fighter is unable to continue, is in danger of serious injury, or is being dominated without a reasonable chance to defend themselves. Fights are also stopped if a fighter submits by tapping, if a cornerman throws in the towel, or if a fighter is knocked unconscious. Medical checks may be required between rounds, and fighters must wear mouthguards and other protective gear. 
Answer