Game Design Perspective: Terraforming Mars


This is the first entry in a series that examines game mechanics - what works, what doesn't, and why.

Since its release in 2016, Terraforming Mars has been storming through the board gaming world. It is the fourth-highest ranked game on the estimable  and the highest-ranked game according to my estimable fiancée, Juliana. We first played it at the end of 2017 and it did not take long for her to order us a copy. We play it once every week or two despite the game's length. The basic game can take between two and two and a half hours, and different expansions and rule variants can increase that to four.


Pictured: Four hours

So what keeps us coming back? The game is extremely replayable. The game has a great variety of winning strategies, and it rewards flexibility during play. You might have to change your overall strategy in the middle of the game, so you are constantly judging your current strategy versus available alternatives.

First, let's take a step back and do a quick rundown of the game. We are playing in The Future, where megacorporations (which sound cooler than "big ol' corporations" and seem more ethical than "uber corporations") are vying to terraform the red planet. Each player represents a megacorp, and they can sponsor projects (cards from their hand) to help improve the planet's prospects. The projects can range from throwing asteroids at Mars (because that raises the temperature) to introducing dogs to the planet (because dogs). There are a number of standard projects that players can purchase at any time, as well as Milestones ("Achievement Unlocked") they can buy and Awards (inter-player contests) they can sponsor. The cards in a player's hand can have one-time effects, lasting buffs, or repeatable actions. On top of that, each megacorp has a unique power that influences what strategies the players lean towards.

Each player starts off with ten cards in their hand, and can get four more at the start of every turn. However, players don't get any of these cards for free. After drawing the cards, players have to spend money to keep them. Many of these cards have requirements that must be met before they can be played. Some requirements won't be met until near the end of the game. Even when you pick up your starting hand, the game already introduces one of the main tensions: do you keep a powerful card, even if you don't know whether it will help out your late-game strategy? The card might be great, but that utility could be contingent on other circumstances that you can't predict. And each card you choose to keep has a very real cost. The more money you spend on keeping cards, the less you have to improve the planet and improve your engine. The designers struck a great balance here with the cost of storing up potential (buying cards) vs. the cost of implementation (playing cards).

To finish the game, players need to max out three terraforming tracks: oxygen, temperature, and the number of oceans. As mentioned before, some cards (especially the powerful ones) have requirements that must be met before you can play them. For example, animal cards require a certain amount of oxygen and plant cards require a certain temperature. If one terraforming track is outpacing the others, then the cards requiring that track become more valuable because their requirements will be met earlier. For example, the card Birds gives you one Victory Point (VP) every turn, but it requires the oxygen track to be nearly maxed out. If oxygen maxes out early, this card is great. If oxygen is the last thing to be maxed out, then you won't be getting many points for Birds. A card's expected value (in terms of VPs) fluctuates throughout the game, depending on where the players' collective terraforming focus lies. A player is always evaluating the changing landscape. This keeps you interested throughout the game, even on the downtime between turns.

Another deft stroke from the designers was to limit that downtime. A player only performs one or two actions before the next player gets to play. If the initial player wants to do additional actions, they can do so after the other players have taken one or two actions themselves. This keeps everyone feeling involved. Even if you have the same absolute amount of downtime, it feels like a lot less when that downtime is broken up into smaller chunks.

There are many ways rack up VPs in this game. Some of the major ways include terraforming, building cities and forests, completing prestigious projects, or playing critter cards that accumulate microbe or animal tokens. For almost any game (not just Terraforming Mars), I find you can categorize strategies into three broad categories: peaceful, competitive, and aggressive. This game features all three. Peaceful routes are more independent and orthogonal from each other. If one player is building a space resort on Jupiter, that doesn't stop me from doing anything else. Conversely, I can't do anything to stop that player from building Space Disneyland, except maybe making snide asides about the morality of doing so. ("Come to Jupiter: No Worker Safety Laws!") Competitive routes have players competing for the same resource. For example, a player gets a VP each time they raise one of the three terraforming tracks. Each time a track is raised, there's one less terraforming VP available for the other players to grab. Aggressive routes have players competing for limited resources *and* players are able to "block" other players. The best example of this is with the ground game, where players place cities and forests. Each forest you own is worth one VP, but each city you own is worth one VP per adjacent forest - whether or not those forests belong to you. I have seen tree planting devolve into a vicious street fight.


Pictured: Bloodbath

While aggressive routes are perhaps the most interesting from a tactical perspective, the game is better for the inclusion of all three types. Different players prefer playing a different kind of game, and having winnable options for all three strategic categories keeps everyone entertained.

Another way the game implements competitive and aggressive routes are the Milestones and Awards. Milestones and Awards both have five options, and only three of each can be bought by the players. Milestones are strictly competitive. After a player meets the requirements, they can spend a set amount of money to claim a Milestone (preventing others from taking the same one) and receive a set amount of victory points. For example, if a player has three cities in play, they can claim Mayor. No one else can claim that Milestone, and only two more Milestones can be purchased. Milestones are typically claimed in the early- to mid-game, and they are worth enough VPs to influence strategy choice. Players who ignore Milestones in an attempt to build their engines will be at a significant disadvantage. For a game as long as Terraforming Mars, it's important to have smaller and shorter cycles of risk-and-reward. The race to claim Milestones in the early-game provides a satisfying source of tension and keeps the beginning from devolving into multiplayer solitaire.

Awards play a little differently. Here, a player purchases an award but they are not guaranteed any VPs for doing so. Instead, a funded Award gives VPs at the end of the game to the player that maximizes some particular aspect of gameplay. For example, an award might grant VPs to the player with the most Science cards or the player that claimed the largest amount of territory. Awards are aggressive routes to VPs because other players can steal the award from the purchasing player if they play their cards right. Awards can be purchased at any time, but typically aren't bought until the end-game. This is because the earlier an award is bought, the greater the risk of losing the accompanying VPs to scheming opponents. To counteract this, the price to buy an Award increases as more are purchased. Buying earlier is riskier, and the tension creates more interesting choices.

The difference between the Milestones and Awards is instructive. An early-game that's more focused on competitive routes and an end-game that's more focused on aggressive routes works well. This is doubly so for engine-building games, where an engine needs time to build up before it can be unleashed. If the early-game has too much of an aggressive flavor, than you can have players knocked out of the running too close to the beginning. Players losing early is bad, as anyone who's ever prayed for a Monopoly game to end can attest to. Having the aggressive parts of the game be nearer to the end means that once players are knocked out (or blocked off from winning), then the game is or is nearly over. That's less time with people sitting around and more time with people having fun.

The game has a huge starting space (or range of possible starting conditions). You randomly get one of 17  corporations and 10 of 208 different project cards. Based on your megacorp's power, you'll decide which of the 10 cards to keep, all while bearing in mind potential combos and synergies. Even in just the base game, you are unlikely to ever draw the same starting 10 cards. (Google puts the odds at 1 in 33,531,149,000,000,000, give or take a few hundred million.) While some cards are variants of each other, the vast majority are distinct enough. This is important, since it means that more of those thirty-three quadrillion starting hands feel unique. There are many ways to win, and any given card is only valuable for certain strategies. Because the combination of your starting megacorp and your initial hand heavily influence your strategy, you never know what kind of game you'll be playing when you first set up the board. Unlike chess, where the opening game has been studied to death, you can't choose ahead of time what sort of strategy you'll pursue. The variety in the starting state of Mars means you will rarely be in the same situation twice. That's a huge plus for replayability.

Thematically, the game executes the terraforming idea splendidly. You start with a dust-filled wasteland of a board and end up with a planet teeming with cities, forests, and oceans. The cards have on-point artwork and flavor text, and there's enough little touches that give the thing a gloss of scientific credibility. (For instance, if you raise the temperature from -2 C to 0 C, the ice caps melt and you get to place an ocean for free.) Some board games can be quite abstract, and their theme doesn't really inform the game mechanics (cough cough Dominion cough cough). Not so here. The cards and their effects make sense in a consistent manner, and they all add to the feeling of being a terraforming megacorporation.

Another angle to look at the gradual terraforming is as 'progress'. A cornerstone of good game design is to make progress explicit to the players. An RPG might have you lose a fight to the Big Bad near the beginning of the game, only to triumph over the foe later on. A platformer might have you revisit an older area, where a mastery of the mechanics makes trivial the formerly challenging. Mars provides this feeling as the board slowly fills. By the end of the game, the board is obviously and attractively different than how it looked at the start. The Terra Nullius (rimshot) of Mars has been carved up into corporate fiefdoms and territories, and you feel like you have brought life to a barren planet.


A less red planet

For all the great things about Terraforming Mars, there are a few minor quibbles I have about the game. First is the length. Two or more hours for two players is a hefty commitment, and Juliana and I are always trying new variants to try to reduce the time needed. The game has lots of systems and moving parts and can be intimidating for new players to learn. Playing with a friendly group, with plenty of take-backs and redos, helps out with this. Finally, your engine can grow very complicated and very unwieldy towards the end of the game. I've played in games where one player has another twenty actions to take after everyone else is done for the round. Everyone sitting around for ten minutes waiting on one player to finish does not make for a good time. Some amount of this is inevitable in an engine-building game, but the game could make tiny adjustments to keep things reigned in. For example, it could limit the number of actions you could take once every other player passes. Alternatively, the game could end immediately once the final terraforming track is completed instead of ending when that round is over.

That being said,  the game is a great example of a well-executed design that stays true to its theme. It has fantastic replay value because of the varied starting conditions, the wide array of winning strategies, and the constantly shifting expected value of any particular card (and, it follows, any particular strategy). It's a long game, but it is time well-spent. Perhaps the highest praise of the game is that after I teach someone to play their first game, they invariably want to play another right away.