The game
Every day World Binder prints a new edition of five world maps. Each map shows the world’s borders as they stood at some point between 1000 BCE and today. Your job is to say when.
You answer with a range of years, from one year to the next. The real answer is also a range: the stretch of years during which that exact map was true. A map of the world in 1914 might only hold for that one year, while a map of the ancient world can hold for decades.
How to play
- Look at the map. Tap or click a territory to read its name, and pinch or scroll to zoom for smaller labels.
- Set the two ends of your range with the year boxes, the plus and minus buttons, or by dragging the handles on the ruler. Drag lower on the ruler for finer steps.
- Press Date it. The game shows the real span, how close you were, and which changes start and end that map.
- Five maps make an edition. Everyone gets the same five maps on the same day. A new edition comes out at midnight, your local time.
Scoring
A range that misses the real span scores 0. A range that overlaps it scores up to 100. The score depends on how much your range and the real span overlap compared with how much ground they cover together, so a wide guess that happens to include the answer earns very little, and an exact match earns 100.
Accounts and rewards
You can play without an account. With one, every point you score becomes XP. Finishing an edition, keeping a daily streak, sharing your result and bringing in new players with your invite link earn extra XP. Levels and milestones unlock themes, titles and other looks for the game. Rewards change how the game looks. They never change scores.
Where the maps come from
The borders come from Cliopatria, a dataset of more than 1,600 polities from 3400 BCE to 2024 made by the Seshat Global History Databank and released under CC BY 4.0. World Binder simplifies and reprojects those borders and splits history into snapshots. A snapshot ends when a polity larger than 50,000 km² appears or disappears, or when one gains or loses more than 150,000 km² or a fifth of its land. That gives 467 maps, and the daily editions draw from them.
Cliopatria records borders at set years and reflects one reading of the historical record. Some dates are rounder than history, some names are the dataset’s own, and its data stops in 2024. Coastlines come from Natural Earth.
Questions and corrections
Spotted a wrong border or name, or have an idea? Use the contact page.