What is a mental model?

A compact idea about how things tend to work, like 'past costs shouldn't steer future choices' or 'a small number of causes often produce most of an effect'. You can carry one from problem to problem. The game is practice at spotting which one a situation calls for.

Is there only one right answer in each room?

Each room has one best fit, and many have one or two near fits that get partial credit. After you choose, the room explains why your tool fitted, partly fitted or missed, and what the best fit would have shown you.

Why do the tools have limited uses?

So the choice matters beyond the room you are in. If you spend a tool on a room where it was only a near fit, you may not have it when a later room needs it. Every dungeon is dealt so that a perfect run is possible with the uses you carry.

Why does backing out cost more each time?

Backing out keeps your tools for later, which is sometimes worth it, but it clears nothing and scores nothing. The cost rises with each retreat (two, then three, then four torch), so backing out of every room always puts the torch out before the exit.

Is today's dungeon the same tomorrow?

No. Today's nine rooms and your kit's uses come from today's date, so the dungeon stays the same all day and changes at midnight on your device. You can also deal a random dungeon at any time.

Can I play with a keyboard?

Yes. Every tool is a button you can reach with Tab, and the number keys 1 to 8 pick the tools in order. B backs out of a room, and after each choice the focus moves to the Next button.

Where are my runs saved?

Only in this browser's local storage: the run in progress and your last thirty results. Nothing is sent to HourLife. Clearing your browser's site data removes them.

Keep this game for later

Games
Mental Model Dungeon

Mental Model Dungeon

Nine rooms dealt from a pool of twenty-four, each a real problem: a project running late, a fee you can't get back, a plan with no room for error. Your kit holds eight thinking tools, each with limited uses. Pick the one that fits, and keep your torch alight to the exit.

Play full screen How it plays

About 8 minutes for nine rooms
A new dungeon each day or deal a random one
No account your runs stay in this browser

How it plays

Read the room
Each room is a short, ordinary problem: a bonus scheme, a cheap car, a kitchen estimate. No room names the tool it needs, so you have to see what kind of problem it is.
Pick a tool from your kit
Eight mental models, each with one or two uses. The best fit clears the room for free and scores three points. A near fit gets you through for one torch and one point. A wrong tool costs three torch, and backing out costs two, then three, then four.
Reach the exit
Every room tells you why the tool fitted or didn't, and which one fitted best. Get through all nine with your torch alight and the end shows what you scored, the tools you read well and the rooms worth a second look.

Why these eight models

A mental model is a short description of how something tends to work, which you can carry from one problem to the next. The eight here come up again and again in ordinary decisions: inversion, second-order thinking, opportunity cost, sunk cost, base rates, margin of safety, antifragility and the Pareto principle.

The hard part is rarely knowing what a model says. It is noticing which kind of problem you are in, when the problem arrives dressed as something else. So every room describes a situation and leaves the label off. Several rooms have more than one reasonable answer, and the game gives partial credit where a tool gets you most of the way.

The uses are limited for the same reason a real week is: reaching for a favourite tool on every problem leaves you without it when it matters. Every dungeon is dealt so that a perfect run is possible with the uses you carry, and backing out of every room always ends with the torch out.

Sources: Daniel Kahneman, Thinking, Fast and Slow (2011), on base rates and the planning fallacy; Benjamin Graham, The Intelligent Investor (1949), chapter 20, on the margin of safety; Nassim Nicholas Taleb, Antifragile (2012); Annie Duke, Thinking in Bets (2018), on sunk costs and premortems.

The books behind the models

Each tool in the kit is drawn from one of these. The end of a run points you at the ones behind the rooms you missed.

Questions

What is a mental model?

A compact idea about how things tend to work, like 'past costs shouldn't steer future choices' or 'a small number of causes often produce most of an effect'. You can carry one from problem to problem. The game is practice at spotting which one a situation calls for.
Is there only one right answer in each room?

Each room has one best fit, and many have one or two near fits that get partial credit. After you choose, the room explains why your tool fitted, partly fitted or missed, and what the best fit would have shown you.
Why do the tools have limited uses?

So the choice matters beyond the room you are in. If you spend a tool on a room where it was only a near fit, you may not have it when a later room needs it. Every dungeon is dealt so that a perfect run is possible with the uses you carry.
Why does backing out cost more each time?

Backing out keeps your tools for later, which is sometimes worth it, but it clears nothing and scores nothing. The cost rises with each retreat (two, then three, then four torch), so backing out of every room always puts the torch out before the exit.
Is today's dungeon the same tomorrow?

No. Today's nine rooms and your kit's uses come from today's date, so the dungeon stays the same all day and changes at midnight on your device. You can also deal a random dungeon at any time.
Can I play with a keyboard?

Yes. Every tool is a button you can reach with Tab, and the number keys 1 to 8 pick the tools in order. B backs out of a room, and after each choice the focus moves to the Next button.
Where are my runs saved?

Only in this browser's local storage: the run in progress and your last thirty results. Nothing is sent to HourLife. Clearing your browser's site data removes them.