Real-time strategy (RTS) refers to a time-based video game that centers around using resources to build units and defeat an opponent. Real-time strategy games are often compared to turn-based strategy games, where each player has time to carefully consider the next move without having to worry about the actions of his opponent. In real-time strategy games, players must attempt to build their resources, defend their bases and launch attacks while knowing that the opponent is scrambling to do the same things.

A real-time strategy game may also be referred to as a real-time simulation or a real-time war game.