How it plays
Nine boundary stones separate you and your opponent. On each turn, place one card beside a stone, then draw its replacement. Each side of a stone holds up to three cards: matching colours, consecutive numbers and equal ranks produce stronger formations than an assorted high total.
Win five stones anywhere along the border, or three next to each other. You can sometimes claim a stone before the opposing formation is finished, but must prove that no possible completion can beat yours using only cards already played.
Decisions you’ll make
A strong formation can still be a poor use of your hand if it wins an isolated stone while your opponent completes a neighbouring trio. Watch the whole border before committing your best card.
Keeping a useful card in hand leaves several formations possible. Playing it narrows those options, but also gives both players new evidence for early claims.
Learning the game
Light: play one card and draw one, with a formation ranking and proof requirement to learn.