Each player controls a beast (a powerful ultralisk or a powerful archon) which they use to attack a terran city. They are given a briefing by an adviser in which they are told that whichever wreaks the most destruction within the time limit wins.
The beasts face numerous opposing terran computer-controlled players.
Each beast can regenerate during the course of the battle by eating civilians by moving toward one, gaining their hit points. If the beast dies, it transforms into a civilian, and can move back into their power circle in order to transform back into a beast. However, they can be eaten by the other beast in the meantime.
The ultralisk continually spawns scourge (one at a time), giving it a form of anti-air attack.
Blizzard Entertainment, Mass Media Inc. StarCraft 64. (Nintendo of America, Inc.) Mission: Rage (in English). 2000.