Passed pawn
A passed pawn has a clear road to promotion as far as enemy pawns are concerned: none stands ahead of it on its own file or the two neighboring files, so the opponent must spend a piece or the king to stop it.
A quick test works on any board. Trace the corridor formed by the pawn's file and the files on either side, from the pawn up to the promotion rank. If no enemy pawn stands anywhere in that corridor, the pawn is passed. Enemy pawns behind it do not count, because pawns never move backward.
The status matters because it creates a permanent chore for the other side. Someone has to watch the pawn on every move, and a piece stuck on guard duty is missing from the rest of the game. In endgames that burden often decides the result by itself, and two passed pawns far apart can overload even a well-placed king. Pawn trades and pawn majorities are the usual ways to create one.
The owner usually wants support before speed: a rook behind the pawn or the king walking beside it lets each step land on a protected square. The defender wants a blockader on the square directly in front, ideally a knight, which keeps working from there.
Watch for pawns that only look passed. If an enemy pawn on a neighboring file can still capture it after one more step, it is not passed yet, as the b5 pawn in the diagram shows.
Compare it with King and pawn endgame. A king and pawn endgame is an ending in which only kings and pawns remain, so the result depends on promotion races, king placement, opposition, and exact counting of moves.
Also worth reading is Outside passed pawn. An outside passed pawn is a passer on a distant wing that works as a decoy: the defending king has to go and stop it, and the moves this takes let the other king win pawns elsewhere.
A neighboring idea is Pawn promotion race. A pawn promotion race is a position where both sides push passed pawns toward promotion, and the result depends on who queens first and what the new queen can do.
Endgame ideas like "Passed pawn" are won or lost on small details, which a coach can check in your own games. The first lesson with George Li is where that review starts.
Related terms
An outside passed pawn is a passer on a distant wing that works as a decoy: the defending king has to go and stop it, and the moves this takes let the other king win pawns elsewhere.
Connected passed pawns are two passed pawns on adjacent files that support each other and can advance together, so the enemy cannot stop them one at a time and they often decide an endgame.
The rule of the square is a shortcut for a lone pawn racing an enemy king: draw a square from the pawn's square up to its promotion square, and the king catches the pawn only if it stands inside or can step in.
A pawn promotion race is a position where both sides push passed pawns toward promotion, and the result depends on who queens first and what the new queen can do.
A king and pawn endgame is an ending in which only kings and pawns remain, so the result depends on promotion races, king placement, opposition, and exact counting of moves.
Guides that go further
What to decide first, the questions to ask, what a first lesson should show and the red flags to avoid.
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A game review, a read on your level and a written study plan from George Li.
Want to spot this in your own games?
A first lesson starts with your games: George reviews them and builds a study plan around what he finds.