Master of Orion is a
turn-based game. In the first iteration of the franchise, one can only play against the
artificial intelligence (AI). Human and AI players control the management of colonies, technology development, ship construction, inter-species diplomacy, and combat. The software generates a map randomly at the start of each game; the player can only choose the size of the galaxy, and the number and
difficulty of AI opponents. In the first game, star systems have at most one colonizable planet and a few have none. Later games have more planets.
Master of Orion has 10 playable races, each with a specialty. For instance, the Humans have advantages in trade and diplomacy; the Bulrathi are the best at ground combat; the Silicoids ignore pollution and can colonize even the most hostile planets, but have slow population growth. Each race is predisposed to like or dislike some of the other races, protected by a powerful warship, the Guardian. Victory is gained either by eliminating all opponents or by winning a vote on peaceful unification. There are seven normal and six hostile planet types. Artifact worlds contain relics of a now-vanished advanced civilization. Planets can be upgraded in three ways: •
Terraforming increases population capacity by a fixed amount for each tech level achieved, up to a maximum of 120 extra units. • Soil enrichment increases a planet's population capacity and growth rate but can not be used on hostile planets. The advanced version increases capacity by up to 50% of its initial value and doubles the rate of population growth. Growth is increased by assigning the planet the modifier "Fertile", and then eventually "Gaia". • Atmospheric terraforming converts hostile planets to normal ones, making soil enrichment possible there. Planet type does not affect the costs and benefits of terraforming and soil enrichment. Sliders are used to allocate a colony's output between ship construction, planetary defenses, factory construction, ecology, and research. Planetary population generates
production, especially when assisted by factories. There is a limit on the number of factories a unit of population can operate, but building upgrades can increase this. Defense spending is used to build additional missile bases, upgrade missile bases or planetary shields. A planet's output can also be transferred to the
treasury at a loss. Ships can travel to any star system within their range and combat always occurs in
orbit over a planet - it is impossible to intercept enemy ships in deep space. Players can control space combat manually or ask the software to resolve combat automatically.
Technology The designers regard technology as the most important contribution to a player's success. Funding can be put into one or all of the game's six independent
tech tree fields, including Computers, Construction, Force Fields, Planetary Science, Vehicle Propulsion, and Weapons. If a ship uses a component from a particular technology area, further advances in that area reduce the cost and size of the component; this effect is called "miniaturization". When one has researched all of the technologies in an area of the tech tree, further research can discover "advanced technologies" in that area, which do not provide specific new capabilities but increase the miniaturization of ship components. Players can design and use their own ships. There are four hull sizes; smaller sizes are harder to hit while larger ships can survive more damage and hold more components. There are eight types of components, each with different effects. Only six ship designs can be used at a time.
Weapons Weapons are used in combat, and can be mounted to ships or given to ground units. When on ships, weapons are often unique and have their own effects, with their own cost and space taken up. Weapons for ground troops make ground defense and attacks more effective.
Special weapons Special weapons are a branch-off of weapons, which do not take up standard weapon slots, rather special slots. these cannot be stacked, unlike standard weapons. They have much more unique effects, and some just make other weapons better, rather than dealing damage themselves.
Biological weapons Biological weapons are designed exclusively for use in attacking planets. They destroy enemy population points and reduce the target's habitability (i.e., its maximum population size), leaving any missile bases and factories there intact. Use of these weapons causes political fallout and every other player in the game shifts a level toward despising their user. Biological defenses, the Bio-Toxin Antidote and Universal Antidote, prevent the loss of 1 and 2 million in population per biological attack respectively. However, neither reduce the damage done by biological attacks to a planet's habitability.
Bombs Bombs are weapons which are designed to attack planets rather than enemy ships. They deal more damage than any other weapon type to colonies, but cannot target ships, and always have the minimum possible range.
Diplomacy Master of Orion provides a wide range of diplomatic negotiations:
gifts of money or technology; one-time technology trades; trade pacts that boost industrial output;
non-aggression and
alliance treaties. Players can also threaten each other, declare war and arrange cease-fires. Each AI player remembers others' actions, both positive and negative, and will be unwilling to form alliances with a player who has broken previous treaties with it. Under AI control, each race has a ruler personality and an objective, such as Xenophobic Expansionist or Pacifistic Technologist. These traits guide their politics and economic management; for example militarists maintain large fleets and prioritize technologies which have military benefits, while ecologists put a lot of effort into pollution control and terraforming. Traits vary from game to game. The invasion itself is fully automatic. Results depend on numbers, technology and (if one of the races involved is Bulrathi) racial ground combat bonus. The production capacity of any remaining factories can be gleaned, and
plundered of technologies if enough factories survived the attack. Controlling a new system extends the range of the invader's ships. ==Development==