Starfleet Orion is a 1978 science fiction strategy game written and published by Automated Simulations (who would become Epyx in 1981). It appears to be the first space-themed strategy game sold for microcomputer systems. The game was originally written in BASIC for the Commodore PET, but later ported to other early home computer platforms including the TRS-80 and Apple II. The game was something of a success, leading to a string of successes for the company, notably the major "hit", Temple of Apshai.
The playfield was a thirty-two high by sixty-four wide grid of possible locations. The map could contain ships, stacked on the same grid space if needed, as well as planets and other objects. The game was turn based, with the two players taking turns at the keyboard to enter their commands, which were then carried out simultaneously. Each player controlled one or more ships, and the game continued until one or both were destroyed, or escaped by flying off the playfield.
Ships were powered by a single energy source whose power had to be divided up among the many parts of the ship, including drives, shields and weapons. Each ship was armed with a beam weapon whose chance to hit a target was based on the target's size and the "beam quality" of the firing ship. The amount of damage caused by a hit was reduced with distance, making it primarily a short-range weapon.
In addition, ships were also armed with missiles or torpedos for long-range fire. Missiles would fly to a location in space relative to the ship after movement and then explode regardless if there was a target in that location. Torpedoes were fired in a particular direction (the eight cardinals) and would explode if they passed within two grid spaces of any other material object (everything except torpedoes). Some ships also included fighters equipped with missiles or torpedoes, which allowed spoiling attacks. Generally the Stellar Union ships had more missiles, and the Orion ships more torpedoes.
Additionally, ships were equipped with a tractor beam that allowed them to push or pull on material objects, allowing complicated strategies of pushing or pulling on opposing ships to throw off their aim. For instance, a torpedo aimed at a ship that was expected to be "due left" after the movement phase could be avoided by the target by pushing the opposing ship a few locations down. The distance a ship could be pushed or pulled was a relative measure of the strength of the beam and the mass of the target. This meant larger ships could spoil the aim of smaller torpedo boats using this method, while smaller ships would be better off simply using their drives to move themselves. Another useful strategy to use the tractor beam to quickly push fighters into range of their targets, at "speeds" their own engines could not achieve.
The game originally shipped on cassette, and required the users to type in the scenario and save it to a separate data tape before playing. The pre-rolled missions were outlined in a separate "Battle Manual", which also included short stories introducing the game world and the individual missions. This process was greatly improved on the diskette versions, which had the games saved out as data files that could be loaded up by name. Users could also create their own scenarios using the separate "BUILDER" program, saving them to tape or disk.
The complex setup and requirement for two players was an obstacle to casual play, which led the programmers quickly release the single-player Invasion Orion. In this game the combined human forces faced the "Klaatu", an extremely powerful alien race. The power of their ships made up for the basic AI the game used, which essentially consisted of the Klaatu ships driving directly at the humans, firing all the way.
Source: Wikipedia, "Starfleet Orion", available under the CC-BY-SA License.