Paper io is about territory control. You begin with a small patch of land and a block that carries your color. As you move, you leave a trail behind. Once you circle back to your land, the enclosed space becomes yours. But there’s a catch: while you’re outside your territory, your trail is exposed. Anyone who cuts through it will eliminate you instantly. This rule makes the paper io game both tense and thrilling, because every decision is a balance between ambition and safety.