Paper io strips territory games to bare logic: go out, draw, come back, claim. There is no fog, economy or meta, only clean collision rules under constant concurrency. The board is simultaneously opportunity and exposure: the spaces you need to grow are exactly where you can be killed. Rivals skim borders, wait for you to step out, and cut the tail. Because a single closure can annex a huge wedge, comebacks are always live. The paper io game is zero-noise design with brutal clarity: you are never confused about why you won or why you died.