In chess, the endgame (or end game or ending) refers to the stage of the game when there are few pieces left on the board. It is the stage of the game that beginners are taught first.
The line between middlegame and endgame is often not clear, and may occur gradually or with the quick exchange of a few pairs of pieces. The endgame, however, tends to have quite different characteristics to the middlegame, and the players have quite different strategical concerns. In particular, pawns become more important; endgames often revolve around attempting to promote a pawn by advancing it to the eighth rank. The king, which has to be protected in the middlegame owing to the threat of checkmate, becomes a strong piece in the endgame. It can be brought to the centre of the board and be a useful attacking piece.
Many people have composed endgame studies, endgame positions which are solved by finding a win for white when there is no obvious way of winning, or a draw when it seems white must lose.
Endgames can be classified according to the type of pieces that remain. Some common types of endgames are discussed below.
King and pawn endgames involve only kings and pawns of both sides. Getting a passed pawn is crucial (a passed pawn is one which does not have an opposing pawn on its file or on adjacent files on its way to promotion). An outside passed pawn, a passed pawn on one of the rook files, is particularly deadly. Opposition is an interesting technique that is used to gain an advantage. When two kings are in opposition, they are on the same file with an empty square separating them. The player having the move loses the opposition. They must move their king and allow the opponent's king to advance.
Rook and pawn endgames are often drawn in spite of one side having an extra pawn. The great master Tarrasch once jocularly said "All rook and pawn endings are drawn". Rook endings are probably the deepest and most well studied endgames. Two thumb rules regarding rooks are worth noting:
A rook on the seventh rank can wreak mayhem among the opponent's pawns. The power of a rook on the seventh rank is not confined to the endgame.
Rooks must be placed behind passed pawns, whether one's own or the opponent's.
An important position in rook endgames is the so-called Lucena position.
In Bishop and pawn endgames, the mobility of the bishop is a crucial factor. A bad bishop is one that is hemmed in by pawns of its own color, and has the burden of defending them. Endings with bishops of opposite color are notorious for their drawish character. They are often drawn even when one side has a two pawn advantage.
Knight and pawn endgames feature clever maneuvering by the knights to capture opponent pawns. While a knight is poor at chasing a passed pawn, it is the ideal piece to block a passed pawn.
In Queen and pawn endings, the dominant theme is for the player with more pawns to avoid perpetual check and advance one of his pawns to get a second queen.
Endings with asymmetric piece possession are less common. A bishop is usually worth more than a knight. A bishop and knight are worth roughly a rook and two pawns, and a queen is worth a rook, a minor piece (bishop or knight) and two pawns. Three pawns are often enough to win against a minor piece, but two pawns rarely are.
Endings with no pawns. A queen or a rook (plus king) can easily checkmate a lone king, and a king and queen can win against king and rook (although it is not always easy to convert). Two bishops can also mate a lone king (providing the bishops move on opposite colour squares) as can a bishop and knight (though this mate is difficult for a player who does not know the correct technique). Two knights cannot force checkmate against a lone king, but if the weaker side also has a pawn, checkmate is sometimes possible, because positions which would be stalemate without the pawn are not (specifically, the pawn must be blocked by a knight behind the Troitzky line).
In general, the player with a material advantage tries to exchange pieces and reach the endgame. In the endgame, it is better for the player with more pawns to exchange pieces but not pawns because king and pawn endings are the most easily won. Also, endings with pawns on both sides of the board are much easier to win.
With the recent growth of computer chess, an interesting development has been the creation of endgame databases which are tables of stored positions calculated by retrograde analysis. A program which incorporates knowledge from such a database is able to play perfect chess on reaching any position in the database.
See chess terminology for definitions of commonly used chess terms.