A world of poor decisions: Could a card game help?

Recently, I put together a simple idea, a card game that would attempt to improve decision making abilities by having people simulate, and actively hunt for biases within a bounded conversation. It was initially designed to reduce susceptibility to logical fallacies, cognitive errors and biases when people were trying to make decisions about what products to build. Product management, at its core, is a game of decisions. And to make quality choices—in a sea of uncertainty and complexity—one needs to ensure the discussions that influence those choices are as free from error as possible. Which is how Homo Rationalis came about.

Homo Rationalis: The Most Rational Being in the Universe

The game is quite simple to play, but I wouldn’t say it is easy. In broad strokes, there are a range of players—most of them ‘rational actors’—and one hidden player who deliberately acts out a bias, drawn at random. Everyone discusses a central scenario, and try to make their case, either for or against, as rationally as they can. All the while the irrational player, the one who is biased, tries to make their case infused with their cognitive bias they have drawn, and go undetected. Everyone’s job is to find the biased actor, and identify what bias is at play. Those who do this well, win the game, and develop a transferable skill that translates into the real world of critical thinking and decision making.

The rules can be found here, but in more detail, it works like so;

1. Priming the Brain: People are exposed to a series of possible biases. This primes their brains to be on the lookout for flawed forms of reasoning and problematic argumentation before the real conversation begins. The reason I implemented this step is two fold; (i) it makes the game a little easier to play for beginners and (ii) it assumes you need no prior knowledge of a wide range of cognitive fallacies in order to play—it levels the playing field, so to speak, and simplifies the game for beginners. Not everyone knows a lot about biases and so this creates a uniformity of abilities between the players. You can, with time, play without this step. In reality, this “no safety net” alteration is how the real world works anyway, so there is nothing to fear here. Biases are always at play in every conversation you have, whether you know what they are called and can identify them or not.
2. Scenarios: Then, a scenario is chosen. A scenario is a kind of container for conversational content. Usually, the scenario is designed to be divisive. People will commonly fall on one side of the argument or the other; Childhood Behaviour is nature not nurture, for instance. Some scenarios are more abstract in nature, requiring one to think more philosophically. And some scenarios are open ended, where you are encouraged to discuss an actual topic which is perhaps contentious within the team, such as whether microservices are a superior strategy.

Each player then (blindly) picks a side. You become either for the argument, or against it. In this way, it sort of resembles a debate.

Players then pick actor cards. They will end up either as one of the rational Homo Rationalis cards, or one of the 185 cognitive biases.

There are also two other unique actor cards, a liar, who does what you might expect, and a moderator, which can be used as a kind of facilitator when games get big and need someone to guide and nudge the conversation.

Why is there a liar?

I introduced the liar to add a different dimension to the game, which mimics life a bit more authentically and adds a little complexity. In many real world conversations, people often speak in half truths, deliberately mislead or often represent facts which are grounded in illusion—for a range of reasons. The liar brings this element to the table and adds a degree of deception and sharpens the focus of others playing. It also means people have to cognitively multi-task. Not only are you looking for someone who is biased, but you must also be on the lookout for other problems within the conversation—namely, someone making things up. As I state in the rules, I consider the liar (as well as the moderator) an optional card which can be used or not.

In simple terms…

In reality, what is really going on is people are just having a discussion around a certain topic, but one individual is really trying to have that conversation and make their case in a nefarious way.

This does a few things…

• Homo Rationalis gets people, very deliberately, paying attention to the content of the conversation, not the actors in it. Most people, when they are discussing things, are usually just waiting for their turn to talk, or latching onto features of the person and using that as a heuristic for the quality of the argument, this is suboptimal. In an ideal world, you want individuals learning to focus on the core of the argument, not the individual (Ad Hominem). This game encourages the act of really listening for the material features of an argument and trains individuals to actively find the problems with that argument as it unfolds. It’s a form of auditory training.
• Secondly, Homo Rationalis trains people to recognize cognitive biases more effectively than passive methods like reading or rote memorisation. It leverages a cognitive strategy known as elaboration, which many suggest enhances memory by linking new information to deeper, more meaningful contexts. When I designed the game, I wanted a way to make the training stick, so leaned on something known as the Levels of Processing model (Craik and Lockhart, 1972). Their theory suggests that information processed more deeply — through analysis, association, and engagement — is more likely to be retained. By actively simulating (acting out) a bias during gameplay, players encode it at a deeper level than they would through surface-level exposure, making future recognition and recall far more likely. That’s the theory at least.
• Thirdly, Homo Rationalis lets players simulate lesser-known biases in the context of real-world problems, making those biases more salient and personally relevant. While some scenarios are light-hearted — like “Ramen is Better than Pho” — others are open-ended, giving teams the chance to bring in real debates from their own workplace. When players overlay cognitive biases onto these live issues, they’re not just learning abstract concepts — they’re surfacing the hidden assumptions shaping their actual decisions. This interlacing of game and reality enhances both insight and impact, turning abstract theory into something tangible and actionable.

How this game funds superior minds of young people

If you’re interested in trying to improve the overall quality of your decisions this may be a very cost effective, albeit challenging, way to do it. But there is also something else to consider when you purchase this game; you are not just improving your decision making abilities, you’re helping young people do the same.

This game (along with other work I do as part of this Decision Intelligence company) has a social upside.

Given how challenging critical thinking and decision making is becoming in a world full of deep fakes and misinformation, I wanted to try and use the work I was doing to improve the decision making faculties of young people, bolstering their cognitive functions and making young minds resistant to cognitive errors.

So, 100% of the profits from Decision Intelligence (which includes both Homo Rationalis and the broader decision making workshops and talks I do to earn a living), goes into funding critical thinking and decision-making training for high school and university students.

The way I figure it, if I can make some money by working on decision making programs within the corporate sector, and funnel that into improving the decision making abilities of young people around the world, perhaps the future will be full of people who can think critically, instead of believing cellphone towers are controlling their wisdom teeth.

You can purchase the game here. for $59.00 AUD.