Tharsis is a tough strategy-simulation game where you must survive a doomed mission to Mars. You roll dice whose outcome can either help repair the ship or make things worse by injuring crew mates or causing further damage. The dice foreground the constant balancing of risk and survival that must be negotiated (and mitigated) if you are to survive.

When humanity detects strange signals from Mars, they send a spaceship and crew to investigate. But as soon as you take off, disaster strikes. The ship is not all it's cracked up to be and continually malfunctions and breaks, risking death or serious injury to the crew. You move crew members around the ship and use their specific number of dice rolls to reach the required total and make the repair. You can also use dice for specific room actions (like health recovery in the Medical Bay), or research sections, which grant you special one-use abilities.

Each astronaut has unique skills suited for specific tasks within the ship, so carefully measured deployment is essential. Rolling specific numbers can result in damage to the crew member, losing that dice, or other negative effects dependent on that crew member's ability. Sometimes, the very numbers you need to repair the ship are a detriment to you, so weighing whether it's worth fixing specific issues is also important. Depending on how many crew members you keep alive, you can get multiple different endings.

Although the dice rolling mechanics make it easy to grasp, it's still becomes a really tough challenge for even players. There is the luck aspect, but it also requires careful consideration of the risks and rewards associated with every action. Finally making it to Mars with all crew members alive after countless attempts is a hugely rewarding end to the game.