In a turn based strategy or real-time strategy, a location or item that produces a resource. In some games (Starcraft, Warcraft), generators contain a fixed amount of resources. In others (Total Annihilation, Disciples), generators produce a steady stream of resources - uncollected resources are lost.

Note that depleted Vespene geysers in Starcraft actually have an infinite amount of vespene; once depleted, resource gatherers can only collect a smaller amount per harvesting trip.