Spacewar

Spacewar was an early video game, a multiplayer space-combat simulation
inspired by Doc Smith's Lensman series of science fiction novels.
Development started on a PDP-1 at the Massachusetts Institute of Technology
in 1962. Today, versions of this classic game are available for a number of
computer platforms, and numerous similar video games have been created.

The basic gameplay of Spacewar involves two armed spaceships attempting to
shoot one another whilst maneuvering in the gravity well of a planet. Each
player controls a ship, and must attempt to simultaneously shoot at the
other ship and avoid colliding with the planet. In most versions, the ships'
missiles are also affected by gravity. Some variants of Spacewar add the
idea of a limited fuel or energy resource for each ship, which is expended
by thrusting or firing and regenerates slowly over time. Many also add a
shield, which can be erected for a short time at the cost of energy, or a
hyperspace warp which transports the ship to a random place on the screen.

Some of the best-known Spacewar derivatives are the Star Control series of
games, created by Toys for Bob. Originally released for MS-DOS and the 3DO
console, these expanded on the Spacewar concept by offering a large number
of ship types, each with its own attack and special ability. Each of the
three Star Control games also added a strategic or adventure game based
around the Spacewar game.