Chain

A chain is a group of same-color stones connected directly, or through other same-color stones, by horizontal or vertical adjacency. Every stone in the chain shares the liberties of the connected unit, so the chain is treated as one unit for purposes of liberties and capture.

Chains provide mutual support and let connected stones function together in fighting, life-and-death situations, and capturing races. A chain is defined by actual stone connectivity; a strategic group may contain several separate chains and may also include broader surrounding considerations. Diagonal contact alone does not connect stones, and stones linked only by a potential connection are not part of the same chain.