Lucha libre is also known for its tag team wrestling matches. The teams are often made up of three members, instead of two as is common in the United States. These three man teams participate in what are called " trios" matches, for tag team championship belts. Of these three members, one member is designated the captain. A successful fall in a "trios" match can be achieved by either pinning the captain of the opposing team or by pinning both of the other members. A referee can also stop the match because of "excessive punishment". He can then award the match to the aggressors. Falls often occur simultaneously, which adds to the extremely stylized nature of the action. In addition, a wrestler can opt to roll out of the ring in lieu of tagging a partner or simply be knocked out of the ring, at which point one of his partners may enter. As a result, the tag team formula and pacing which has developed in U.S. tag matches is different from lucha libre because the race to tag is not a priority. There are also two-man tag matches ("parejas"), as well as "four on four" matches ("atomicos").