Berzerk is a multi-directional shooter video arcade game, released in 1980 by Stern Electronics of Chicago.

The player controls a green stick man, representing a humanoid. Using a joystick (and a firing button to activate a laser-like weapon), the player navigates a simple maze filled with many robots, who fire lasers back at the player character. A player can be killed by being shot, by running into a robot or an exploding robot, coming into contact with the electrified walls of the maze itself, or by being touched by the player's nemesis, Evil Otto.

The function of Evil Otto, represented by a bouncing smiley face, is to quicken the pace of the game. Otto is unusual, with regard to games of the period, in that there is no way to kill him. Otto can go through walls with impunity and is attracted to the player character. If robots remain in the maze Otto moves slowly, about half as fast as the humanoid, but he speeds up to match the humanoid's speed once all the robots are killed. Evil Otto moves exactly the same speed as the player going left and right but he can move faster than the player going up and down; thus, no matter how close Otto is, the player can escape as long as they can avoid moving straight up or down.

Alan McNeil, an employee of Universal Research Laboratories (a division of Stern Electronics), had a dream one night involving a black-and-white video game in which he had to fight robots. This dream, with heavy borrowing from the BASIC game Robots (Daleks in the UK), was the basis for Berzerk, which was named for Fred Saberhagen's Berserker series of science fiction novels. "Evil Otto" was named after Dave Otto, security chief at McNeil's former employer Dave Nutting Associates. According to McNeil, Otto would, "[smile] while he chewed you out." He would also lock McNeil and his fellow employees out of the building to enforce a noon-hour lunch, as well as piping "beautiful" music into every room.

The idea for a black-and-white game was abandoned when the color game Defender was released earlier the same year to significant success. At that point Stern decided to use a color overlay board for Berzerk. A quick conversion was made, and all but the earliest versions of the game shipped with a color CRT display. The game was test-marketed successfully at a Chicago singles bar before general release.