Trapped piece — what it means in chess
A piece with no safe square, won by attacking it.
A piece with no safe square, won by attacking it.
A trapped piece has nowhere safe to go — every square it can reach is covered, occupied, or leads back into the cage. Trapped pieces fall without ever being attacked twice: the opponent closes the exits at leisure, then collects. The classic cause is greed on the edge of the board, where a piece's mobility is at its minimum and a single pawn move can seal the tomb.
The a2 and a7 pawns have buried enough bishops to have earned a nickname for the pattern: the entombed bishop.
[[board startfen="6k1/8/4b3/8/8/8/PPP5/3K4 b - - 0 1" pgn="1... Bxa2 2. b3 Bb1 3. Kc1 Ba2 4. Kb2 Kf8 5. Kxa2" caption="The poisoned pawn: the bishop grabs on a2, one pawn move seals the tomb, and the king collects." notes="Black to move, and the a2 pawn looks free. Bxa2 — taken. The bishop is now in the corner of the board, where its eight possible squares have become two. b3 — the tomb closes. The bishop's diagonal home is cut: b1 is the only retreat, since a desperate capture on b3 loses the bishop to the c-pawn at once. Bb1 — into the last corner. Kc1 — the king strolls over. No urgency: the bishop is going nowhere. Ba2 — the only shuffle left, back and forth between two squares. Kb2 — the king arrives next door, covering b1. Kf8 — Black's king can only watch from across the board. Kxa2 — collected. The bishop cost a pawn to trap and nothing to win: the exits were the whole battle."]]
Before any piece grabs a distant pawn, count its exits after the capture — the pawn on a2, like the pawn on b2, is priced below market for a reason. A piece en prise loses material once; a trapped piece loses it slowly, in front of an audience.
The Endgame Society glossary defines more than 240 chess terms — rules, notation, tactics, strategy, pawn structures, endgames, and openings — in language a beginner can act on rather than dictionary shorthand.