The number on the store page
The official description says: Conquer 80% of the world to win. That is the target to plan around.
The numbers on recorded end screens
A world win showed VICTORY and the line: You conquered the world with 80.2% of the land outside fallout.
A team win showed: Your team won with 80.1% of the land.
So the threshold sits at about 80%, and the screen reports the share you actually hold. The world screen subtracts fallout. The team screen that was recorded did not use the words outside fallout. Do not treat 80.2 as a different ruleset from 80. It is one match crossing the line.
What counts as land
Only the fallout exception is documented, and only on that world victory sentence. There is no published rule here for water, unclaimed tribes, or allied land. Assume you need your own color on enough non-fallout land, and check the percentage the match itself shows.
How matches end early
If your borders are overrun, the game shows YOUR NATION HAS FALLEN and ELIMINATED. That can happen in the middle of a small regional map when one rival breaks through. You do not have to reach 80% for the match to end for you.
A finish that matches the rules
- Keep one main attack and enough troops on the other borders to avoid the elimination screen.
- Connect new land so the percentage you gain is land you can still defend.
- If nukes are flying, remember fallout land was excluded on the recorded world win.
- Stop picking optional fights once the match percentage is approaching 80 and your borders are stable.
No ranked ladder, season, or placement reward is described on the official page.