A tactic used in Real Time Strategy(RTS) games involving quickly building up a swarm of low level units and attacking an enemy base before they have time to put up any defenses. Often considered a cheese strategy a good rush is hard to execute and harder to defend against. The term grunt rush was first termed during the days of Warcraft and has survived to encompass many new units such as the tank rush from the Command and Conquer series and the zergling rush from Starcraft.