The game is played in rounds, each consisting of the following phases:
In-game a year contains four rounds corresponding to the four seasons. At the start of a round is a Weather phase where every space can lose or gain Humidity, Chaos and weather effects such as Snow or Frostbite, which can cause the tile on that space to change. This is followed by a Planning phase where players decide what orders to give their tiles and units. These orders are executed in the Action phase. In the Decay phase, Gas, Frostbite and Firestorm wreak havoc. At the end of the round there is a Night phase, where populated tiles gain power and generate income.
At the end of every Decay phase players without City tiles are defeated. If each City tile controlled by a player is occupied by an enemy unit, that player loses control of those City tiles and is also defeated. The game ends when only one player remains undefeated, or when all other players have resigned. The winner gains rating according to their current rating and the final game score.