Paintball is an extreme sport in which players compete, in teams or individually, to eliminate opponents by tagging them with capsules containing water soluble dye and gelatin shell outside (referred to as paintballs) propelled from a device called a paintball marker (commonly referred to as a paintball gun). Paintballs are composed of a non-toxic, biodegradable, water soluble polymer. The game is regularly played at a sporting level with organized competition involving worldwide leagues, tournaments, professional teams, and players. Paintball technology is also used by military forces, law enforcement, para-military and security organizations to supplement military training, riot response, and non-lethal suppression of dangerous suspects.

Games are played on outdoor or indoor fields of varying sizes. A game field is scattered with natural or artificial terrain, which players use for tactical cover. Rules for playing paintball vary, but can include capture the flag, elimination, ammunition limits, defending or attacking a particular point or area, or capturing objects of interest hidden in the playing area. Depending on the variant played, games can last from seconds to hours, or even days in scenario play.