YORIMICHI PLAYLISTHOW TO PLAY
Controls and goals
- Controls
- Click or tap "CHEAT" or "COOPERATE."
- Objective
- Examine the conditions that foster trust by simulating choices between cooperation and betrayal.
ABOUT THE GAME
Through binary choices and a scoring table...
...discover the conditions for cooperation.
"The Evolution of Trust" is an interactive guide to the game theory of cooperation. Players choose to either "cooperate" or "cheat," with their scores determined by the choices made by both parties. The experience progresses into repeated matches between various strategies, followed by a simulation where the parameters can be adjusted.
COOPERATE OR CHEAT
The party that cooperates receives -1 point,
while the party that cheats receives +3 points.
The screen shown here illustrates an outcome where the cooperating party received -1 point and the cheating party received 3 points. The layout places the scoring table at the center alongside the next set of choices, allowing players to connect the previous outcome with their subsequent decision.
Gameplay footage: Yorimichi Playlist Editorial Department (audio off) / Created by Nicky Case
Four possible outcomes
The scoring table displays four possible combinations: both parties cooperate, you alone cheat, the other party alone cheats, or both parties cheat.
Repeated matches between various strategies
Strategies with different rules—such as always cooperating, always cheating, or mimicking the opponent's previous move—are pitted against one another under identical conditions.
Adjusting parameters in the Sandbox
In the latter "Sandbox" section, users can modify the initial distribution of strategies, the number of rounds, the point values for each outcome, and the rate of "misunderstandings," then observe how the proportions of these strategies shift over time.
PLAY NOTES
Play notes
- Languages
- You can switch from the English version to a fan-translated version (including Japanese).
- Cost and Licensing
- Available for free on the official website. Content created by the author is licensed under CC0-1.0; external assets are subject to their respective licenses.
- Playtime
- The official walkthrough/guide takes approximately 30 minutes.
Cooperate, or betray?
Start by inserting a coin.
The official play page, repository, and annotations were verified on July 19, 2026. The two images provided are in-game screenshots captured by our editorial team from the official browser-based version. Sources: Nicky Case’s "The Evolution of Trust" — Official Play Page, Official Repository and Licensing, Nicky Case’s "The Evolution of Trust" — Official Annotations, Nicky Case — FAQ
STREAMING INFO
Streaming and video uploads
While the author’s original content is under CC0, the official version includes sound effects licensed under CC BY and CC BY-NC. For non-monetized streams that include audio, please ensure you adhere to the attribution requirements for each asset. If you intend to monetize your content, please remove or replace the game’s audio, and obtain permission from the rights holders if necessary.
READER COMMENTS
Comments on The Evolution of Trust
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