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Endgames

Pawn Endgames: opposition, key squares and the rule of the square

Updated Jul 27, 2026 · 5 min read

The rule of the square, the opposition, key squares and the rook pawn draw: the four ideas that decide every king and pawn endgame, explained with diagrams.

Pawn endgames have no gray area: the position is either won or drawn, and what usually decides which one is whose turn it is. This is the most exact part of chess, and almost everything in it comes down to three tools: the rule of the square, the opposition and key squares.

The rule of the square

A passed pawn runs for the promotion square, and the question is always the same: can the king catch it? No move-by-move calculation is needed. Picture a square with the pawn in one corner and the promotion square in the corner above. A defending king inside that square, or stepping in on its own move, catches the pawn; a king outside it, with the pawn running first, does not.

The square of the h4 pawn runs from d4 to h8. The black king on c6 is one file outside it, and the white king on a1 is too far away to help.♚♟♚abcdefgh87654321
The square of the h4 pawn runs from d4 to h8. The black king on c6 is one file outside it, and the white king on a1 is too far away to help.
  1. Count the moves the pawn still needs. The h4 pawn needs four: h5, h6, h7 and h8.
  2. Draw the square with the pawn in one corner. Here the corners are h4, h8, d8 and d4.
  3. A king inside the square catches the pawn; a king outside it, with the pawn moving first, does not.

With White to move: 1.h5 Kd6 2.h6 Ke7 3.h7 Kf7 4.h8=Q and the new queen is safe. With Black to move the result flips: 1...Kd6 steps into the square, and after 2.h5 Ke7 3.h6 Kf8 4.h7 Kg7 the pawn falls: the king attacks h7 and guards the promotion square. Same position, two results.

The opposition: the player not to move is in charge

Two kings can never stand on adjacent squares. When they face each other on the same file with one empty square between, the king that has to move must step aside. That is the opposition, and here is the part that trips people up: the side that has the opposition is the side that is not to move.

Kings on e4 and e6 with the empty square e5 between them. White is to move and has to give way, so Black holds the opposition.♚♚abcdefgh87654321
Kings on e4 and e6 with the empty square e5 between them. White is to move and has to give way, so Black holds the opposition.

It works at long range too: kings on the same file, rank or diagonal with an odd number of empty squares between them (one, three or five) are in opposition, and the player not to move is in charge. With an even number in between, whoever is to move takes it by stepping forward.

Key squares: what your king is aiming at

The opposition is not the goal, it is the tool for taking the key squares: squares that guarantee promotion once the stronger side's king reaches them, whoever is to move. For an e-pawn they are always the same three: d6, e6 and f6.

The three key squares of the e4 pawn: d6, e6 and f6. With accurate defense, the white king reaches none of them here, and the game is drawn with either side to move.♚♟♚abcdefgh87654321
The three key squares of the e4 pawn: d6, e6 and f6. With accurate defense, the white king reaches none of them here, and the game is drawn with either side to move.
  • Pawn on e4 (fourth rank): keys two ranks in front, on d6, e6 and f6.
  • Pawn on e5 (fifth rank): keys one rank in front, the same d6, e6 and f6.
  • King on the sixth rank with its pawn right behind on the fifth: a win with either side to move.
  • The fifth rank is not enough: king on e5 with the pawn on e4 wins only if Black is to move.

Take the white king on e5, the pawn on e4 and the black king on e7. If Black has to move, Black gives ground: 1...Kd7 2.Kf6 and the white king has taken f6, a key square, so the pawn promotes. If White has to move, White steps aside and the game is drawn. Hence the rule that governs the whole endgame: the king leads, the pawn follows. Pushing the pawn too early is the number one mistake.

The defending king belongs in front of the pawn

For the defender there is one recipe: king in front of the pawn, on its file. Beside or behind the pawn, the king holds nothing. With a white pawn on e4 and the white king on e2, a black king on e7 draws without effort; the same king on a5 loses even with the move: it cannot get back in time.

Once the king is in front, the defender gains one more resource: stalemate. White king on d6, pawn on e6, black king on d8, White to move: the natural advance throws the point away, 1.e7+ Ke8 2.Ke6, and Black has no legal move. Draw. With Black to move, that same position is lost: 1...Ke8 2.e7 Kf7 3.Kd7 and the pawn promotes.

The rook pawn exception

A pawn on the a-file or the h-file is the great exception. If the defending king reaches the corner, the game is drawn however well the attacking king is placed. No maneuver or opposition trick changes it.

A rook pawn on h6, the white king on g6, the black king in the corner. With the black king on h8, or on g7, this is a draw whoever is to move.♚♚♟abcdefgh87654321
A rook pawn on h6, the white king on g6, the black king in the corner. With the black king on h8, or on g7, this is a draw whoever is to move.

In the diagram, 1...Kg8 2.h7+ Kh8 3.Kh6 leaves Black stalemated: h7 is occupied and defended, g7 and g8 covered. Every other try drops the pawn.

The reason is geometric: on a central file the attacking king walks around the defender on either side, and the defense collapses for lack of space. On the h-file there is no "either side": the board has run out. Move that pawn from h to g and many of these positions become wins. Worth knowing before you trade down to a single rook pawn.