Paintball is a combat sport in which participants eliminate opponents from play by hitting them with paintballs (spherical gelatin capsules containing primarily polyethylene glycol, other non-toxic and water-soluble substances, and dye) shot from a compressed-gas-powered "marker".
Paintball draws a wide array of players, and the Sporting Goods Manufacturer's Association estimates that over 10 million people play annually in the United States alone. Insurance statistics show that paintball is one of the safest sports in existence, even more so than tennis.
Games can be played either indoors or outdoors and take various forms, of which some of the most popular are woodsball, scenario and speedball, also sometimes known as tourneyball under various circumstances.
The majority of paintball markers have four main components: a body, a hopper, a tank, and a barrel. There is, however, a strong following of stock-class players who use markers with a purposely low rate of fire and capacity. Stock-class markers are usually pump-action and powered by 12-gram CO2 powerlets.
The paintball community generally prefers to use the term "marker" rather than "gun" in order to mitigate the public perception that paintball markers are weapons, and that paintball is a dangerous sport. The term derives from its original use as a means for forestry personnel and ranchers to mark trees and wandering cattle.