Terraforming Mars is a cooperative board game set in the year 2400, when humanity begins terraforming the planet Mars.

• Each player plays one of the large corporations sponsored by the world government on Earth, to initiate large projects to increase the temperature, oxygen levels, and ocean coverage until the world is habitable.
• As a company, you collaborate in the terraforming process, but you compete for victory points, which are awarded not only for your contribution to terraforming, but also for advancing human infrastructure throughout the solar system.
• When the three global parameters (temperature, oxygen, ocean) have reached their target, terraforming is complete. The game also ends, and the winning player is determined.

Prelude is an expansion to Terraforming Mars, and can be combined with any other Terraforming Mars expansion or variant.