How to play

Each duel shows two cards and one question. Size Duel asks about one measure: Which is longer?, Which is taller?, Which rises higher above sea level? or Which is heavier? Older Than asks Which came first? Population Duel asks Which country has more people? Further North? asks Which city is further north? Each card says what its value means (for example “diameter”, “ground to tip of the torch”, “opened” or “first published”).

Answering

Tap or click a card, or press 1 or 2 (the left and right arrow keys work too). Your first answer is final. The reveal shows both values, a drawing and a short note. Press Next (or Enter) when you’re ready; nothing moves on by itself.

What makes a duel fair

Duels only compare the same measure. In Size Duel the bigger value must be at least 15% bigger, and for animals and other things that vary, the whole range of typical adults must stay on one side: a bigger-than-usual one could never flip the answer. Approximate values (a rounded figure, or an exact conversion of one) are shown with “about”. Dates must be at least two years apart, so two things from the same year never meet; approximate dates (to the decade or century) need 20 or 200 years, and years before the Common Era count without a year 0. Countries duel only when one has at least 10% more people than the other. Cities duel only when they are at least one degree of latitude apart, about 111 km.

The drawings

Size Duel’s silhouettes are original drawings made for this game, each in its real proportions. On the reveal they share one scale: a person (about 1.7 m), a bank card (85.6 mm) or a scale bar shows how big that scale is. When one thing is far too small to see, it is also shown enlarged in a circle, with the enlargement written next to it. Masses are drawn as bars on one scale. Older Than puts both dates on a time ruler. Population Duel draws both populations as rows of figures, each figure standing for a round number of people, and compares how crowded each country is per square kilometre of land. Further North? draws both cities’ lines of latitude on a globe and on a close-up latitude scale.

The daily rounds

Each deck has ten duels a day, the same for everyone, mixing easier and harder duels. The day changes at midnight UTC. Finish a deck’s round on its own day to add a day to that deck’s streak; your score doesn’t matter. If you start before midnight UTC, you have until 02:00 UTC to finish and still count it. Past days are in the archive; replays never change your streak. Every daily uses new pairings until a deck runs out; a day that includes duels from earlier days is labelled a repeat.

Endless streak and practice

The endless streak goes on until your first miss, gets harder as it grows and never repeats an item before the whole deck has appeared. Practice rounds take ten duels from the whole deck or from one category, group or region. Neither changes your daily streak.

Saving

Your round is saved in this browser after every answer. Close the tab and come back: you continue at the same duel. Nothing is sent to a server.