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. If you have Evil Otto right on your tail, you can escape as long as you only do not have to move up or down. After 5,000 points Evil Otto doubles his speed, moving as fast as the player while robots remain in the maze, and twice as fast as the player after all the robots are destroyed.
The player advances by escaping from the maze through an opening in the far wall. Each robot destroyed is worth 50 points. Ideally, all the robots in the current maze have been destroyed before the player escapes, thus gaining the player a per-maze bonus (ten points per robot). The game has 64,000 mazes, and each level is designed to be more difficult to finish than the last. It has only one controller, but two-player games can be accomplished by alternating at the joystick.
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 for a disliked fellow-employee.)
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.
Probably the best-remembered feature of Berzerk is that the robots talk. This was one of the first video games to use speech synthesis.
In 1980 computer voice compression was extremely expensive—estimates were that this cost the manufacturer US$1,000 per word; the English version had a thirty-word vocabulary. Stern nevertheless did not spare this expense, and some non-English versions were made, for example a Spanish version in which the robots would say "Intruso alerta" and "El humanoide no debe escapar,".
Another memorable feature is the action of the robots—unlike adversaries in most other contemporary games, Berzerk's robots are known for being noticeably "stupid," killing themselves by running into walls or each other, shooting each other, or colliding with Evil Otto. Advanced players learned how to manipulate this quirk to their advantage to achieve a higher score. Notably, points and bonuses for the player are the same regardless of whether he or she personally kills the robots—as long as the robots are destroyed, the points are awarded. This feature also somewhat balanced the indestructibility of Evil Otto.
Two different versions of the game were released. As a player's score increases, the colors of the enemy robots change, and the robots can have more bullets on the screen at the same time (once they reach the limit, they cannot fire again until one or more of their bullets detonates; the limit applies to the robots as a group, not as individuals). In the original version, the sequence goes:
The revised version, which had the much larger production run of the two, features a longer color sequence that also included purple, green, and light blue robots. In this version, the robot sequence went up to five normal speed bullets, then they began firing fast bullets, starting with one fast bullet, and eventually going as high as seven fast bullets at once. After 20,000 points the robots stay light blue and may have up to seven fast bullets on screen for the remainder of play. To balance the greatly increased threat from the robots in this version, Evil Otto's pursuit speed remains at its normal (half or equal the player's speed) level throughout.
In both versions, a free man can be awarded at 5,000 and/or 10,000 points, set by internal DIP switches.
Experienced players almost always moved from left to right (escaping through the right-hand door) because of the geometry of how the robots and human character both shot (going up/down or down/up would lessen the time needed to avoid Evil Otto). In a dire situation a shot fired from a robot could be made to pass through the neck of the player without killing him, referred to by some players as the "bulletproof bowtie" (this was duplicated in the Atari 2600 version).
The game units were particularly known for failure of the optical joystick unit; Stern suffered the cancellation of about 4,200 orders for new games because of previous purchasers' bad experiences with these joysticks. The company responded by issuing free replacement joysticks in a leaf-switch design by Wico.
Berzerk was the first video game known to have been involved in the death of a player. In January 1981, 19-year-old Jeff Dailey died of a heart attack soon after posting a score of 16,660 on Berzerk. In October of the following year, Peter Burkowski made the Berzerk top-ten list twice in fifteen minutes, just a few seconds before also dying of a heart attack at the age of 18.
Milton-Bradley produced a Berzerk board game designed for two players, one playing Evil Otto and the robots, the other playing the hero. The playing pieces were plastic yellow rectangular panels that were labeled with the corresponding characters. The hero figure was differently shaped and labeled only on one side. It also had a slot in which a second piece was inserted representing the character's arms, both equipped with laser pistols. Pressing down on the back tab raised the guns and if the figure were properly positioned in the space, would knock down a robot. Firing the weapon counts as one move.
Stern later released a similar game called Frenzy as a sequel, and a Berzerk coin-op can be converted to Frenzy simply by replacing one processor (ZPU-1000 to ZPU-1001) and installing a different game ROM. The game also served as an inspiration for later, more sophisticated games such as Castle Wolfenstein, Shamus, and Robotron: 2084.
In the episode "Rose Bowl" on the television show News Radio, Bill calls Dave "Evil Otto" ("Like staring into the gaping maw of Evil Otto!"). Later, in the same episode, Catherine calls Bill "Evil Otto."
The "Bishop Of Battle" story from the film Nightmares is based on Berzerk: a game so hard and so frustrating that you can die from playing it.
In the Futurama episode "Fear of a Bot Planet," the robotic policemen along with the loudspeaker use the sound samples of "Get the humanoid!" and "Intruder alert!" from the original game. The episode "Anthology of Interest II" also references the style of the sound samples ("Fork 'em over! FORK 'EM OVER!").
In the My Name is Earl episode "Joy's Wedding," Darnell "Crab Man" Turner can be seen playing the Atari 2600 version of Berzerk. He also has a "Wall of Fame" containing Polaroid pictures of his high scores.
A Cracked.com article entitled "The 10 Most Terrifying Video Game Enemies of All Time" listed Evil Otto as number one, citing the two deaths attributed to the game and remarking that "[H]e is possibly the only video game enemy in history to kill players in real-life" and "Evil Otto watched them die ... with a smile on his face.
Talking Android Attack was a clone of Berzerk for the Dragon 32 and Tandy Color Computer, marketed in the UK by Microdeal. As the name implies, it featured several speech clips, including "intruder alert" and "I'll get you next time" - though the quality was far worse than that of the real arcade game.
The game's voice synthesizer generates speech for the robots during certain in-game events:
There is also random robot chatter playing in the background, phrases usually consisting of "Charge", "Attack", "Kill", "Destroy", or "Get", followed by "The Humanoid", "The intruder", "it", or "the chicken" (the last only if the player got the "Chicken, fight like a robot" message from the previous room), creating sentences such as "Attack it", "Get the Humanoid", "Destroy the intruder", "Kill the chicken", and so on. The speed and pitch of the phrases vary, from deep and slow, to high and fast.
In 1982, Buckner and Garcia recorded a song titled "Goin' Berzerk", using sound effects from the game, and released it on the album Pac-Man Fever. It is in a ballad form that contrasts with the frenetic nature of the game.
Independent breakbeat artist Phaser 500 recorded a song titled "The Machine Will Get You" comprised entirely of video game sound effects which included the "the humanoid must not escape" quote from the game.
Richard D. James recorded a track entitled "Humanoid Must Not Escape," which samples the eponymous robot quote, for alias Caustic Window's 1998 album Compilation. James later reused samples from the video game in the song 54 Cymru Beats on his 2001 album Drukqs under his Aphex Twin alias.
In the TV Sitcom My Name is Earl (Season 1, episode 8), a character is portrayed, playing Berzerk and scoring high. He afterwards would take a polaroid photograph of the screen, pinning the highscore to his personal wall of fame.