騎馬戦, lit. cavalry battle
A game usually involving groups of three or more, but often four. As the others hold him or her steady from below in a triangle formation, a rider sits atop the pyramid as they battle against other groups. A win is achieved by capturing a hat, flag, or knocking the rider off their horse.
A two person variation, commonly called a chicken fight, involves someone riding atop another's shoulders.
Cavalry battles and chicken fights may be played on ground or in a pool. Although chicken fights are seen as dangerous, cavalry battles are a common staple of Japanese school sports festivals.