Paintball is a game in which players compete, in teams or individually, to eliminate opponents by hitting them with capsules containing water-soluble dye and featuring a gelatin outer shell (referred to as paintballs) propelled from a device called a paintball marker (commonly referred to as a paintball gun). The balls can be quite painful and cause bruising on direct hit. The participants wear protective goggles to protect their eyes. According to Halacha is it permitted to partake in such games?
While this form of recreation may be questionable in terms of the spirit of the game, it poses no halachic problem of causing injury to others.
The objective of the game is not to inflict injury, rather the sport of hunting down the other team and their flag. The slight bruising is incidental to the game. This would be similar to playing football and hockey which also often lead to some bruising in the course of the game. Yet being that this is not the intent there is no prohibition in engaging in activity which may cause bruising. This is unlike boxing or other fighting sports where the intent is to inflict harm and pain on the opponent.