Paintball is a sport whose participants use compressed-gas markers to shoot paintballs (roughly marble-sized, .68 caliber, gelatin capsules filled with colored polyethelene glycol) at other players. Once marked by a paintball, a player is eliminated from the game. The first paintball game was played in New Hampshire in 1981 by Bob Gurnsey, Hayes Noel, Charles Gaines, and nine others, who used markers built to tag cattle or trees. The first tournament with a cash prize was held in 1983.