Player Interaction in Terraforming Mars: Attacks, Blocks, and Races

Terraforming Mars has a reputation as a game where everyone builds their own engine and the others are scenery. Our engine building explainer says as much. That is fair for a first game. At Level 3, it is no longer true. There are at least five ways your turn touches someone else’s, and using them well wins close games.

1. Red-bordered attacks

From the rulebook: a red border means an effect can target any player, including you.

• Removing red-bordered resources is optional. You may take fewer, or none. All of them must come from one player.
• Lowering red-bordered production is required. If no opponent has that production, you lower your own, or you cannot play the card.
• Red-bordered tiles and tags target any or all players’ tiles or tags.

Who to hit. The usual answer is the leader. But the better answer is the player who loses the most from it. Removing 3 plants from someone with 9 stops a greenery this generation. Removing 3 from someone with 4 does much less. The same card can be worth very different amounts depending on the target.

When it hurts you to attack. An attack spends a card and an action on hurting one player while everyone else gains. At four or five players, that often helps the players you did not hit. Attack when the swing is big, not by habit.

2. Protecting yourself

The resources most open to attack are the ones sitting on your board. A few habits help:

• Convert plants as soon as you have 8. Plants waiting for a better space are plants waiting to be taken.
• Spend heat when the temperature is open. It is not a common target, but a rival maxing the temperature takes all its TR value away.
• Watch production. Some cards lower another player’s production. If you are the only player with a production type, you are the only possible target.

3. The map

The tile placement lesson covered how the map scores. Its interactive side:

• Block a city site with your own city, since cities may not touch.
• Take a placement bonus a rival is building toward.
• Place a city next to a rival’s greenery cluster. Their greeneries must follow their own tiles, so your city scores from their future placements too.
• Avoid feeding rivals. Every greenery you place next to a rival’s city is a point for them.

4. Races

Milestones and awards are the clearest contests in the game.

• Milestones go to whoever claims first, and only 3 of 5 can be claimed. If a rival is one step from a milestone you also want, claiming it now takes 5 VP from them and 8 M€ from you. Claiming a different milestone also helps, since it brings the total closer to 3.
• Awards pay first and second place no matter who funded them. Funding an award your rival leads gives them points. Funding one you lead, even narrowly, can force them to spend to catch you.

Two actions in one turn let you qualify and claim before anyone reacts. The rulebook calls out this use of two actions directly.

5. The clock

This is the biggest lever of all. Every step of terraforming moves the same clock, and the midgame lesson explained who wants a long game and who wants a short one.

If the leader has a huge engine and you are ahead on points, raise the parameters. Each step you take shortens the game and cuts off generations of their income. If a rival is ahead on TR and you have the bigger engine, play cards that pay you without raising the tracks, and let the game run.

Watch for windows too. A card that requires oxygen at 9% or lower closes when the table passes 9%. Raising oxygen at the right moment can make a rival’s card unplayable.

Playing nicely while playing well

Interaction does not need to feel mean. A few ways to keep the table warm:

• Say what you are doing and why. “I’m taking your plants because you’re winning” lands better than silence.
• Do not gang up. Two players hitting the same rival every turn can sour a game night.
• Know your group. Some tables love attacks. Some would rather build. Read the room before the game, not after.

Interaction as a habit

Before each turn, look up from your cards. Who leads? Who is near a milestone? Which parameter is closest to done, and whose plans does it close? You will not act on every answer. But asking every turn is what turns a solo engine into a real game against real people.