Asteroids (video game)

**Asteroids** is a multidirectional shooter arcade game created by Atari, Inc. and released in 1979. Atari handled development and publication, while Taito and Sega released the game in Japan. Players pilot a triangular spaceship through a field of drifting asteroids, which is also visited by flying saucers. The goal is to destroy all asteroids and saucers by shooting them, while avoiding collisions with rocks or enemy fire. Difficulty increases as the number of asteroids on screen grows.

The game was designed by Lyle Rains and Ed Logg, who built it on hardware originally created by Wendi Allen (then known as Howard Delman) for the earlier game *Lunar Lander*. *Asteroids* evolved from an unfinished project called *Cosmos*. Its physics, controls, and gameplay were inspired by *Spacewar!*, *Computer Space*, and *Space Invaders*, and were refined through trial and error. The visuals appear on a vector display, with a two-dimensional view that wraps around both the top-bottom and left-right edges of the screen.

*Asteroids* became one of the first major successes of the golden age of arcade games. Atari sold 47,840 upright cabinets and 8,725 cocktail cabinets. The game was widely imitated and directly influenced later titles such as *Defender* and *Gravitar*. In the 1980s, it was ported to Atari’s home systems; the Atari 2600 version alone sold over three million copies.

**Gameplay**

The player controls a triangular ship that can rotate left or right, fire straight ahead, and thrust forward. Once the ship moves in a direction, it continues drifting until the player applies thrust in another direction or until momentum naturally fades and the ship stops. The ship can also enter hyperspace, which teleports it to a random location on screen—but this may cause it to self-destruct or reappear on top of an asteroid.

Each level begins with several large asteroids drifting across the screen. Objects that move off one edge reappear on the opposite edge, continuing in the same direction. Shooting a large asteroid breaks it into smaller, faster pieces that are harder to hit but worth more points. Two types of flying saucers appear periodically: the “big saucer” fires randomly and inaccurately, while the “small saucer” fires frequently at the player’s ship. After the player reaches 40,000 points, only the small saucer appears. As the score increases, the small saucer’s shots become more accurate, eventually hitting with extreme precision. When all asteroids and saucers are cleared, a new wave of large asteroids appears, beginning the next level. The game becomes harder as the number of asteroids increases, until the score reaches between 40,000 and 60,000 points. The player starts with three to five lives and earns an extra life every 10,000 points. Play continues until the last ship is lost. The maximum high score is 99,990 points, at which point the machine “turns over.”

**Lurking exploit**

In the original design, saucers were supposed to start shooting as soon as they appeared, but this was changed. Additionally, saucers can only aim at the player’s ship when it is on screen; they cannot aim across a screen boundary. This allowed a “lurking” strategy: by staying near the edge opposite the saucer and keeping only one or two rocks in play, a player could shoot across the boundary to destroy saucers indefinitely with little risk. Arcade operators complained about lost revenue from this exploit. Atari responded by issuing a patched EPROM, and the incident led Atari and other companies to change their development and testing policies to prevent similar exploits in future games.

**Development**

*Asteroids* was conceived by Lyle Rains and programmed by Ed Logg, with help from other Atari staff. Logg, impressed by the Atari Video Computer System (later the Atari 2600), joined Atari’s coin-op division to work on *Dirt Bike*, which was never released after an unsuccessful field test. Paul Mancuso served as the game’s technician, and engineer Wendi Allen contributed the hardware. In April 1979, Rains discussed *Planet Grab*, a multiplayer arcade game later renamed *Cosmos*. That unfinished game featured a giant, indestructible asteroid. Logg played *Cosmos* and remembered shooting the indestructible rock to no effect. Rains then asked Logg, “Well, why don’t we have a game where you shoot the rocks and blow them up?” Logg described a similar concept in which the player selectively shoots rocks that break into smaller pieces. The two combined the two-dimensional approach of *Space War* with the addictive “completion” and “eliminate all threats” gameplay of *Space Invaders*. Both agreed on the concept.

**Hardware**

*Asteroids* runs on hardware developed by Allen. It is a vector game, meaning graphics are composed of lines drawn on a vector monitor. Rains initially wanted raster graphics, but Logg—experienced with vector displays—suggested an XY monitor because its high image quality allowed precise aiming. The hardware consists mainly of a MOS 6502 microprocessor running the game program, and a QuadraScan high-resolution vector graphics processor (also called an “XY display system” or “Digital Vector Generator”). The original design concepts for QuadraScan came from Cyan Engineering, Atari’s off-campus research lab in Grass Valley, California, in 1978. Cyan then passed the design to Wendi Allen.