A common paintball mantra
among rich yuppy scum
meaning to shoot a lot of expensive
paintballs with the hope of obtaining accuracy by volume
A slight variation on the sniper saying "One Shot One Kill", people who play by the One Case One Kill style usually carry an obscene amount of paintballs with them (a case worth) and have ridiculously expensive paintball guns so that they can shoot a lot, really quickly.
This attitude spawned new variations on classical "forest paintball" such as speedball and hyperball. Many times this attitude takes a lot from the game because stealth, strategy, and tactics are often forgotten. People will tend to bring a lot of paint, find a good spot, and slowly pick off people by shooting a lot and trying to get lucky.