noun, noun which may take the genitive case particle 'no'
off the board; outside the game board
Used in go, shogi, and similar board games to refer to matters or actions that occur outside the actual game board, such as psychological tactics, external distractions, or off-board analysis.
盤外戦も勝負のうちだ。
Off-the-board tactics are also part of the match.
彼は盤外の雑音に動じなかった。
He was not disturbed by the noise outside the board.