the "big saucer" shoots randomly and poorly, while the "small saucer" fires frequently at the ship. After reaching a score of 40,000, only the small saucer appears. As the player's score increases, the angle range of the shots from the small saucer diminishes until the saucer fires extremely accurately. Once the screen has been cleared of all asteroids and flying saucers, a new set of large asteroids appears, thus starting the next level. The game gets harder as the number of asteroids increases until after the score reaches a range between 40,000 and 60,000. The player starts with 3–5 lives upon game start and gains an extra life per 10,000 points. Play continues to the last ship lost, which ends the game. The machine "turns over" at 99,990 points, which is the maximum high score that can be achieved. Lurking exploit In the original game design, saucers were supposed to begin shooting as soon as they appeared, but this was changed. Additionally, saucers can only aim at the player's ship on-screen; they are not capable of aiming across a screen boundary. These behaviors allow a "lurking" strategy, in which the player stays near the edge of the screen opposite the saucer. By keeping just one or two rocks in play, a player can shoot across the boundary and destroy saucers to accumulate points indefinitely with little risk of being destroyed. Arcade operators began to complain about losing revenue due to this exploit. In response, Atari issued a patched EPROM and, due to the impact of this exploit, Atari (and other companies) changed their development and testing policies to try to prevent future games from having such exploits. Development Concept Asteroids was conceived by Lyle Rains and programmed by Ed Logg with collaborations from other Atari staff. Logg was impressed with the Atari Video Computer System (later called the Atari 2600), and he joined Atari's coin-op division to work on Dirt Bike, which was never released due to an unsuccessful field test. Paul Mancuso joined the development team as Asteroids technician and engineer Howard Delman contributed to the hardware. During a meeting in April 1979, Rains discussed Planet Grab, a multiplayer arcade game later renamed to Cosmos. Logg did not know the name of the game, thinking Computer Space as "the inspiration for the two-dimensional approach". Rains conceived of Asteroids as a mixture of Computer Space and Space Invaders, combining the