Prisoners

Prisoners are the stones that are taken off the board after their liberties are reduced to zero.

Depending on the rule set, prisoners either

• are tossed back to their original supply, or
• are kept separate and visible (e.g. in the lid).

See Samsung 2004 Dispute for what happens if there is any confusion about that.

(In Chinese, capturing a stone on the board is called "吃子" and taking it off the board is called "提子".)