Each turn, players will draft and simultaneously play a card from their hand ("pack") to indicate their action for the turn. This may be moving citizens or airships to explore or expand around the modular board, building structures, researching technology, initiating conflict, producing or gathering resources, and abating radiation. All of these things can earn you points in different ways. If you cannot store resources, they are left on the ground and are available for anyone present to use. Each card has an action and a lesser version of another action, so you're never stuck being entirely unable to do a particular thing, and you can also store cards for future.
Once all actions are complete, hands are passed to the next player and a new card is added to each one. If a "Winter" card is added, it is discarded and replaced, and the game timer advances. As the game timer advances, both expected events (spread of radiation, combat, feeding your citizens) and unexpected events may occur. When the Winter track reaches the end, the game is over, and points are scored.