Terraforming Mars: Ares Expedition

The base game supports 1–4 players. Normally choose one of two corporations, receive eight project cards and your corporation’s starting benefits, and start at five terraforming rating. Start temperature and oxygen at their minimums with nine unflipped oceans. The manual provides first-game card presets.

Each round has Planning, Resolve Phases, and End steps. Secretly select a phase card simultaneously, reveal it, and retrieve your previous choice. You cannot select the same phase in consecutive rounds.

Resolve only phases selected by at least one player, in Development, Construction, Action, Production, Research order. Everyone participates simultaneously, each phase occurs once regardless of how many selected it, and each selector receives its bonus.

Development allows one paid green project; its selector reduces that card’s cost by three MC. Each steel capability discounts building-tag projects by two MC; each titanium capability discounts space-tag projects by three. These apply across card colors, are not spent, and cannot reduce a cost below zero.

Construction allows one blue or red project. Its selector may play another, or draw one card before or after playing. Ocean, oxygen, and temperature requirements use the state at the start of the phase. A project card in hand can be discarded for three MC at any time.

Action normally permits each in-play card’s Action ability once; its selector may use one again. Standard actions can repeat: eight plants or twenty MC for a forest; eight heat or fourteen MC for temperature; fifteen MC for an ocean. At phase end, spend usable plants or heat on standard terraforming while the corresponding parameter remains below its maximum.

Production supplies MC production plus current terraforming rating, and plant, heat, and card production; its selector gains four extra MC. Research normally draws two and keeps one; its selector draws five and keeps two instead, discarding the remainder. Rebuild an empty project deck by shuffling its discards.

Each parameter step normally adds one terraforming rating. Throughout the phase when a parameter reaches its maximum, players may still gain the prescribed benefits for raising it; extra ocean effects use the last flipped ocean’s reward. Later phases give no further benefits for raising that parameter, though building forests still awards forest points.

At round end, reduce your hand to ten and gain three MC per card discarded this way. Once temperature reaches +8°C, oxygen reaches 14%, and all nine oceans are flipped, finish only the current phase, then score terraforming rating, forests, and projects. Break ties by total heat, MC, and plants; convert unwanted hand cards to MC before comparing.

Base solo uses twenty-five rounds. Shuffle five extra phase cards as a dummy hand; reveal one each round to activate that phase without a selector bonus. Reshuffle after each five-round group, choosing the dummy order for the final five rounds. On the first four reshuffles, Novice/Advanced assists raise oxygen or temperature two/one steps without rating or forest points; Expert gives no assistance. Finish all terraforming before time expires to win.