Expeditions sent by the governments of eight races came to orbit around Gallius IV. An armed conflict ensued as each race was determined to capture the planet for its own purposes. To avoid an intergalactic war, as well as to prevent the disputed planet from being accidentally destroyed by the space fleets battling around it, a treaty called The Compact of Gallius IV was signed by seven of the eight races. Each of the seven would deploy five hundred lightly armed colonists to the planet, who would then each begin developing a colony. No restrictions were put on weapons developed and used by the colonies, as opposed to the colonists only being allowed to bring laser pistols with them. The colony to drive all others off the planet's surface, or to construct a pre-set number of cities, would claim the planet for its leaders. The recently discovered and neutral Tolnans serve as advisers to everyone, while the Skirineen operate the local black market.
The game can be played against a number of human opponents (over the Internet), or against the computer. Before starting, the player picks one of seven races to lead, modifies the desired size of the planet, its basic geological make-up, the number of enemies, the number of City Centers required to claim victory and the landing site. The colony starts with a small population, which grows in size every turn. By constructing various kinds of buildings, collecting/producing resources and researching technologies, the colony can be greatly expanded. Each can field as big an army as it can support.
Military units are divided into sea, land, air and missile, each type produced by a different line of buildings. Specialists, such as spies, are trained in City Centers. Units can only be given combat orders in advance - the player is presented with a video recording of a battle after one has occurred.
There are two modes: the "world view", where the colony leader can move armies, trade resources with or attack other colonies, and the "settlement view", where colony management (such as town planning and building) takes place.
The map is divided into "provinces", which can differ in land type and the amount of natural resources (food, wood, iron, energy, and, later in the game - Endurium) available. Natural resources are unlimited, but different resources are gathered at different rates on different land types.
Capturing all of the other colonies’ territories or constructing a pre-set number of City Centers wins the game. The latter is much more difficult than it seems: each consecutive City Center is more expensive than the last.
Source: Wikipedia, "Deadlock: Planetary Conquest," available under the CC-BY-SA License.