Tragedy of the Bunnies: Revised with in-class options

The original February 2015 post was substantially edited in September 2015 to reflect the unavailability of the original online game.  Tragedy of the Bunnies was taken offline in April 2015, but returned again in March 2016. As of January 2019 it is again unavailable online.

Tragedy of the Bunnies is a free online game that quickly teaches the basic lesson of the Tragedy of the Commons.  It takes less than 5 minutes to play and was rather an elegant way of introducing the lesson to students, ideally as homework assignment the night before a class discussion on the topic. It has a checkered online history–it was offline for a year from February 2015-2016, and returned again in March 2016. The principles of the game are easily recreated in a classroom exercise, useful to have in case the game goes offline again.

In the online game, you play as a bunny merchant who make their living by catching bunnies and selling them as pets to children.  You start out playing the ‘public game’, where there is an open field of bunnies and you want to catch as many bunnies as possible before your competitors snatch them up.  If you try to avoid catching some, the other merchants will clear the field, leaving you with nothing and the fields empty of bunnies.  Everyone loses in the public game, because the population iss completely depleted and your future employment prospects are bleak.  You then play the private game, where the open field of bunnies is now divided by fences, and you own some of the bunnies outright.  The private game is played in two rounds, and any rabbits left in round 1 would triple in number for round 2, allowing you to maximize the number of rabbits caught while also preserving future stock.

Quick, fun, and instructive, the bunny game is therefore a great teaching tool as an introduction to the basic logic and implications of the depletion of the commons.  As its online presence is unreliable, though, let’s think through some ways we can recreate this in the classroom.

One way would be to simply keep a tally on the board.  Note that there are 30 bunnies in the pasture, draw a simple indicator of each bunny, and designate 3 players. The goal is to get a minimum of 20 bunnies; the winner is the player who gets the most bunnies beyond 20 (failing to get 20 means they lose).  Give each player a different colored marker or chalk, and either have them circle a bunny in term, or give them 10 seconds to circle as many bunnies as they can to claim them.  Tell them that any bunnies left in the pasture will procreate in the next round, but do not allow the players to communicate (as the other two players in the online game were AI-controlled).  If all 3 players seem unwilling to claim any bunnies in the first ‘public’ round, you can invite another student to come up and claim them–after all, the bunnies are on common land and anyone can hunt them.

Next, redraw the bunnies, but divide them into 3 groups of 10, and tell the players they can only hunt their own bunnies.  See if this time, they allow some to stay around and procreate–since they triple in value between round 1 and 2, it would be very easy to get 20 bunnies this way.

You could also involve the entire class in this and make it more physical by planting ‘bunnies’ around the classroom–I used wadded up pieces of colored paper–and letting the students race each other to collect them.  The same rules work–any ‘bunnies’ left undisturbed will triple in the 2nd round.  In the private round, i give each student their own collection of bunnies and let them turn in as many as they want in each round, again with them tripling in the 2nd round.

These in-class versions of the game will take more time than the online version did–perhaps 20-30 minutes, rather than the 5 minutes Tragedy of the Bunnies demanded.  But it is still worthwhile to consider playing out the game with your students, as it really can help them understand this essential concept.