
Rationality Cardinality is a party game for sneakily exposing yourself and your friends to useful concepts, in the most amusing possible way. The rules are similar to those of Apples to Apples or Cards Against Humanity: In each round, one player reads a Question card, and each other player selects an Answer card to match it. Unlike those games, however, the cards are designed to simultaneously make you laugh, and teach you something.
If you really want to learn about heuristics and biases, logical fallacies, and how to reason well, and you want to learn as quickly as possible, then you should go read books. Or blog posts. Definitely don't spend that time hanging out with your friends enjoying life. But if you're going to be enjoying life anyways, you can simultaneously learn things, and enjoy harder, if you have a deck of Rationality Cardinality around.
What do we mean by "rationality"? Rationality Cardinality builds on the Less Wrong definition, which defines rationality as having two branches: epistemic rationality means strategies for figuring out what's true, and instrumental rationality means strategies for achieving our goals.
A statement which doesn't answer a question, but does make some people stop thinking about it.You may have heard of a game with similar rules, called Cards Against Humanity, which is made by different people and bears no relation to Rationality Cardinality. While it is theoretically possible to treat Cards Against Humanity as an expansion to Rationality Cardinality and mix its cards into your game, this is not recommended because Cards Against Humanity's cards have different backs, and are for horrible people. Rationality Cardinality is much classier:
One danger with a game like this was making it inaccessible. Many of the cards build jokes on concepts from fairly advanced and obscure fields. That's why the cards have clear and accurate explanations.
We all wish our friends would be more rational, especially when they disagree with us. But actually helping them can be difficult, especially when already in an argument. Rationality Cardinality will help you teach your friends how to think more clearly, by introducing them to concepts in a fun and memorable way.
| Typical Strategy | Suggested Strategy |
![]() | The slippery slope fallacy water park If you go down the water slide, it's a short walk to the roller coaster, and before you know it, blood sports! Where will it end? |
The cardinality of the set of Rationality Cardinality cards is finite, but Rationality Cardinality is massive, with 100 question cards and 400 answer cards. While dense in jokes, this is a thorough treatment of important fields, concepts, and jargon, and a few passes through the deck and the enclosed bibliography will have you well prepared to participate in top-tier intellectual discussion.
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