Downed opponent

The referee will promptly bring the downed opponent to his or her feet to resume the bout standing.

The only combat sport which allows strikes when the opponent is down is mixed martial arts.

The majority of MMA organizations follows the common rule of prohibiting knee strikes and kicks to the head of a grounded opponent, but fighters are allowed to strike their opponent's body.

Hand and elbows strikes to the head are considered legal.

Pride Fighting Championship was the first large organization which adopted soccer kicks, knees and stomps to the face/head of downed opponent.