P4: Tragedy of the Commons

For Thomas Hsieh, Katherine Liu, Kavita Selva, Melody Yang

Artist’s Statement

“The tragedy of the commons is a situation in which individual users, who have open access to a resource unhampered by shared social structures or formal rules that govern access and use, act independently according to their own self-interest and, contrary to the common good of all users, cause depletion of the resource through their uncoordinated action.” – Wikipedia

We made Tragedy of the Commons, a game roughly based on the phenomenon of the same name. The premise of the game is surviving in a post-apocalyptic world, and the last player standing wins. In order to survive, a player must have a population of size greater than zero at all times and may not have more than one consecutive turn with zero food. A limited pool of food is accessible by all players, but one player’s greedy actions can leave others starving. A player’s population is limited by the amount of food they have, and the amount of food they can get is limited by their population. The two resources balance each other out. Players must also plan ahead for catastrophes which happen every three turns. One particularly catastrophic event can wipe out a player’s population, taking them out of the game.

Through our game, we want players to experience the consequences of taking resources from unregulated but limited shared resources for their own benefit with no regards for others. Not only does it negatively impact other players when one player takes all the food from the pool, but it also affects a player’s own resources when their population grows out of control and cannot sustain itself on such little food.


For P4, we wanted to refine the balance of the game. When playtesting P3, we found that the resource cards were too powerful, and there was not enough incentive to attempt challenges. To fix this, we reduced the rewards gained from Free Resource cards. We also found that players who invested in their population early in the game could win easily, because there was not enough penalty for overpopulating and running out of food. We added the rule that having no food left when a Food Catastrophe hit would kill the player immediately, and that having no food would reduce the population. Originally, when players ran out of food, they would lose if they still had no food in the subsequent round. We found that it was easy to avoid having no food for consecutive rounds, so very few players died from starvation. By shaving off the population over time, we increased the difficulty of the game and applied more pressure to players with large populations.

When playtesting P3, we also found that players who lost early had nothing to do for the rest of the game. We added roles for dead players: After they died, they could choose to become a Herbivore or Carnivore. Herbivores could steal Food and Carnivores could kill one Person. This mechanic kept dead players engaged in the game, and it also introduced more social fun, as dead players ganged up on the surviving players and introduced more chaos to the game.

We also noticed that there were a lot of rules to keep track of, and it was a bit overwhelming to remember how many turns were left until catastrophe, when to consume food, and when to reduce the number of Free Resource and Challenge cards were at play. To simplify things, we removed the rules that changed the number of cards at play when players died. We also made Reference cards that listed out the actions at each stage of the game, so Players could keep track of when players took actions, when animals took action, and what to do at the end of a round.

Finally, we introduced changes to stay consistent with the fiction of the game. Our game was set in a post-catastrophe world, but our original cards were bright and colorful. We changed the font and used darker colors, and we also added in some humorous flavor text. We also added a penalty for failing challenges to fit the narrative. The harder challenges were things like hunting bears, which should carry some risk. Failing the challenge should thus result in losing people. Reducing the population when running out of food also helped reinforce the narrative of starving.


Here are the rules of Version 3 of Tragedy of the Commons!


This game is for 4-6 players.

  • 4 players: start with 3 Free Resource cards, 3 Challenge cards on the table
  • 5-6 players: start with 4 Free Resource cards, 4 Challenge cards on the table

At the beginning of each round, make sure there are always the proper number of Free Resource cards and Challenge Cards on the table.

Shuffle the rest of the cards in their respective decks and lay them face down on the table

  • 1 deck of Free Resource cards
  • 1 deck of Challenge cards
  • 1 deck of Catastrophe cards

Players each start with 2 People tokens in a color of their choosing and 3 Food tokens. Food tokens are shared among all players. There should be no more than 45 Food tokens at all times. This includes Food tokens owned by players and Food tokens in the public domain.

Food tokens

  • Starting with 5-6 players: 45 Food
  • Starting with 4 players: 30 Food


  1. For the first round, decide who goes first in a fair way (roll dice, rock paper scissors, whose birthday is next, etc.). Play order goes clockwise. In subsequent rounds, the player who goes first rotates clockwise. That is to say, in the second round, the first player is the person who played second in the previous round, and the last player is the person who played first in the previous round.
  2. On your turn, you have 1 action.
    1. Take a Free Resource card – Immediately get the resource(s) listed on the card (People or Food) and place the card in the Free Resource discard pile. Do not replace the card until after the round is over.
    2. Start a Challenge – Send some People to do a new Challenge. Challenge cards will reward more resources than Free Resource cards, but they require a certain number of People to do them. However, keep in mind that you will only get the rewards if the person requirement is met exactly. You may send any number of People up to the number listed on the card. To send People to do the Challenge, place People tokens on top of the circles on the Challenge card. Leave them there until the end of the round.
    3. Join a Challenge – If a player previously in the round sent People to a Challenge but did not send enough needed to finish the Challenge, you may help complete the Challenge by sending some of your People as well. The rewards given by the Challenge card will be proportional to the number of People you sent. For example, if the Challenge card requires 5 People and rewards 10 Food, and you sent 3 People, you would receive 6 Food at the end of the round. (Note: players are allowed to converse and agree to collaborate on a Challenge, although players are also allowed to betray each other…)
  3. The round ends when everyone has taken their turn. If there are Animals, they take their turn now.
  4. If you completed a Challenge, you can receive your rewards now. However, if the People requirement for the Challenge was not met, you will not receive any rewards, and you discard People according to how far below the requirement you were. For example, if the challenge required 5 People but you only sent 3 People, each player who participated in the Challenge discards 2 People.
  5. Take back any People that you sent to do Challenges, even if you did not receive rewards. Place completed Challenge cards in the Challenge card discard pile and replace missing cards.
  6. Replace any missing Free Resource cards.
  7. Subtract 1 Food per 2 People that you have. If you have an odd number of People, round up. For example, if you have 5 People, subtract 3 Food. Do not worry about negative numbers. Negative Food is the same as 0 Food. If you do not have enough Food to feed all your People, you discard one third of your population, rounding up. 
  8. Move the round counter up by 1. After you reach 3 rounds, draw a Catastrophe card and replace the counter back at 0. Every player must immediately discard the number of People or Food listed on the Catastrophe card. Place the card in the Catastrophe card discard pile. If you have 0 Food left and the Catastrophe requires you to discard Food, you die immediately.
  9. If you have 0 People left, you die immediately. Your Food does NOT go back to the Food pile. Any Food that a player has when they die is permanently out of the game.
  10. If there are no more Food or People tokens left in the general pile, the game rounds proceed as normal, except you don’t get any resources for completing Challenges or taking Free Resources. You still have to do Steps 6 and 8.
  11. If there are no more cards, shuffle the discard pile and place it face down again.
  12. The game ends when one player is left standing!

Dead Players

When you die, you become an Animal. At the time of death, choose whether to be an Herbivore or Carnivore. Place an Herbivore or Carnivore role card in front of you so that other players can see. Animals execute their actions during the Animals’ turn.

Herbivores can take up to X amount of Food tokens among all the players, where X is one less than the number of starting players. Herbivores can take all X Food from one player, one Food from each of X players, or some Food from several players that add up to no more than X.

Carnivores kill one Person from any alive player. They cannot kill People participating in Challenges. The amount of People they can kill does not scale based on how many players are left in the game.


Download and print the game here. Make sure to print double-sided.

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