# The Schelling Game (a.k.a. the Coordination Game)

Summary
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The **Schelling Game** (or Coordination Game) is a simple but fun party game that seems to have been independently invented several times. (One might even say it represents a Schelling point in game-space...) I have played it both with LessWrong meetups and with other groups; good times were had by all. This article describes the rules of the game as I've seen it.

The purpose of the game is to discern [Schelling points](https://en.wikipedia.org/wiki/Focal_point_(game_theory)) among the group. You should have at least 4 players; there may be an upper limit at which the game becomes unwieldy, but I've never seen it get that large. (The most I've seen was about 15 players, and that seemed to work fine.) No materials are required, although paper-and-pencil are helpful.

On each turn, play proceeds as follows:

1.  Someone (the "prompter") names a category (e.g. "Living people").
2.  Everyone (including the prompter) precommits to some answer in response.
3.  Everyone reveals their answer, and each player gets as many points as there are *other* players giving the same answer.

A *round* is completed when every player has given one prompt. The number of rounds should be set in advance, usually such that there are 10–20 prompts in total. (The game tends to get boring if it goes on much longer.) At the end, whoever has the most points wins.

Rule variants
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The unanimous answer rule
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If all players give the same answer for a prompt, then under the basic rules everyone would get the same number of points, so the turn is effectively a wash. To discourage this, and encourage more interesting prompts, you can say: If everyone gives the same answer, then everyone gets 0 points, except for the prompter, who loses 1 point.

Sudden-death tiebreaker
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If, at the end of the pre-set number of rounds, multiple players are tied for first place, you can enter a "sudden-death round" to determine the winner. Take turns giving prompts in the same order as before, but skip any player involved in the tie. All players should answer the prompt, but only the first-place contenders are eligible to earn points. The game ends as soon as the tie is broken, regardless of whether the turn order has completed.

Talking during turns
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Under the most strict rules, all players must be silent after the prompt is given and before the answers are revealed (since anything said aloud might create a new Schelling point). You may find that this makes the game less fun, so you can relax this restriction; but in any case, players should not blurt out answers while others are still thinking. If this happens, you can declare that answer to be excluded.

Details
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Precommitment mechanism
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It's the prompter's job to determine when everyone has come up with an answer, and to tell everyone when to reveal them.

It may be tempting to say "Just mentally commit to an answer; we trust you not to change it after hearing other answers." I would strongly discourage this: even if everyone's being honest, it's easy to subconsciously rewrite one's own memory of what one's answer is. Rather, there should be some tangible evidence of the precommitment. You can write it down on paper; or, if paper is lacking, the prompter can count down and have everyone say their answer at once, and then go around the circle to repeat the answers one at a time. Even if the simultaneous shouting is indiscernable, the act of physically speaking the answer will prevent any subconscious memory-rewriting.

Online play
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The game is also suitable for playing in online chats. You can set up an editable-by-all Google spreadsheet like this:

|     | **Name a living person** | **(The next prompt...)** |
| --- | --- | --- |
| **Alice** | (Alice's answer) |     |
| **Bob** | (Bob's answer) |     |
| **Carol** | (Carol's answer) |     |
| **Dave** | (Dave's answer) |     |

On each turn, each player should enter their answer in the corresponding cell, *without pressing Enter*. This will make the cell turn gray for everyone else, indicating that some text has been written into the cell but not yet revealed. When it looks like everyone has written something, the prompter should confirm that everyone has settled on their final answer, and then count down "3, 2, 1, go!" whereupon everyone presses Enter to reveal their answer.

Disputes over matches
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Determining whether two answers are "the same" may be subjective, but you can usually resolve this by consensus (unless, I suppose, you're playing for a cash prize, but I've never done this myself). You don't really have to read this section before playing, but you can refer to these heuristics if questions arise:

*   Supercategory/subcategory (e.g. "dog" vs. "poodle") is **not** a match.
*   Two different names for the same thing **are** a match, as long as at least one party to the match knew about the synonymy beforehand. (And you can't give answers whose meaning is unknown at the time the prompt is given, e.g. "Whatever Alice's answer is.")
*   The answer should at least attempt to match the prompt; i.e. it has to be plausible that someone might believe that the answer matches the prompt. For example, if the prompt is "What is the 123,456,789th digit of π?" then any decimal digit may be accepted. Generally, however, you should avoid giving prompts with a single correct answer. If the prompt specifically excludes one or more answers, then those answers (or any synonyms thereof) should not be accepted.

Questions to consider
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1.  Is it possible to get good at this game?
2.  Does this game teach any useful skills?