Glossary of Chess

Dark squares: The 32 dark-coloured squares on the chessboard, such as a1 and h8. A dark square is always located at a player's left hand corner.
Dark-square bishop: One of the two bishops that moves on the dark squares, situated in c1 and f8 in the initial position.
Dead draw: A drawn position in which neither player has any realistic chance to win. A dead draw may refer to a position in which it is impossible for either player to win (such as insufficient material), or it may refer to a simple, lifeless position which would require a major blunder before either side would have a chance to win.
Decoy: This is a chess tactic used to lure a piece to an unfavourable square.
Defence: 1. A move or plan which tries to meet the opponent's attack.; 2. An opening played by Black, for example the Scandinavian Defence, King's Indian Defense, English Defense, etc.
Deflect: The inverse of a decoy (see above). Whereas a decoy involves luring an enemy piece to a bad square, a deflection involves luring an enemy piece away from a good square; typically, away from a square on which it defends another piece or threat. Deflection is thus closely related to overloading (see below).
Demonstration board: A large standing chess board used to analyse a game or show a game in progress. Johann Löwenthal invented the demonstration board in 1857.
Descriptive notation: An old system of recording chess moves, used primarily in the English and Spanish speaking countries through the 1970s or 1980s. Now replaced by the standard algebraic notation.
Desperado: 1. A piece that seems determined to give itself up, typically either to bring about stalemate or perpetual check.; 2. A piece to sell itself as dearly as possible in a situation where both sides have hanging pieces.
Develop: In the opening, moving a piece from its original square to make it more active. To redevelop a piece means to move it to a better square after it has already been developed.
Diagonal: A line of squares of the same colour touching corner to corner, along which a queen or bishop can move.
Discovered attack: An attack made by a queen, rook or bishop when another piece or pawn moves out of its way.
Discovered check: A discovered attack to the king. This occurs when a player moves a piece, resulting in another piece putting their opponents king in check.
Domination: A situation whereby capture of a piece is unavoidable despite it having wide freedom of movement. Usually occurs in chess problems.
Double attack: Two attacks made with one move: these attacks may be made by the same piece (in which case it is a fork); or by different pieces (a situation which may arise via a discovered attack in which the moved piece also makes a threat). The attacks may directly threaten opposing pieces, or may be threats of another kind: for instance, to capture the queen and deliver checkmate.
Double check: A check delivered by two pieces at the same time. A double check necessarily involves a discovered check.
Doubled pawns: A pair of pawns of the same color on the same file; generally considered a weakness due to their inability to defend each other.
Doubled rooks: A powerful position in which two of a player's rooks are placed on the same file or rank with no other chessmen between them. In this position, they defend each other while attacking both laterally and along the shared row. The position especially can be decisive when achieved during the endgame phase of play.
Draw: A game that ends without victory for either player. Most drawn games are draws by agreement. The other ways that a game can end in a draw are stalemate, threefold repetition, the fifty-move rule, and insufficient material. A position is said to be a draw (or a "drawn position" or "theoretical draw") if either player can, through correct play, eventually force the game into a position where the game must end in a draw, regardless of the moves made by the other player. A draw is usually scored as ½ point, although in some matches only wins are counted and draws are ignored.
Drawing line: An opening variation that commonly ends in a draw, for example 1.e4 e5 2.Nf3 Nc6 3.Nc3 Nf6 4.Bb5 Nd4 5.Nxd4 exd4 6.e5 dxc3 7.exf6 Qxf6 8.dxc3 Qe5+ 9.Qe2 Qxe2+, a line in the Rubinstein Variation of the Four Knights Game. See Collection of drawing lines at chessgames.com. Often such a variation is played because one or both players are eager to draw the game.
Drawish: An adjective describing a position or game that is likely to end in a draw.
Draw odds: A type of chess handicap where one player (Black in an Armageddon game) only has to draw in order to win the match.
Drawing weapon: An opening line that a player plays with the intent of drawing the game. This may or may not be a line commonly thought of as a drawing line. In high-level chess and correspondence chess, a player well-versed in opening theory may even use as a drawing weapon a sharp opening that has been analyzed to a drawn position in a number of lines, such as the Marshall Attack in the Ruy Lopez, and the Sveshnikov and Poisoned Pawn variations of the Sicilian Defense. One example of the successful employment of a drawing weapon was the 2000 World Chess Championship match between Garry Kasparov and Vladimir Kramnik. In that match, Kramnik used the Berlin Defense to the Ruy Lopez as a drawing weapon with great effect. Kramnik drew all four games with that opening, drew all the rest of his games as Black, and won two games as White, with no losses.
Duffer: A weak chess player, also referred to as a "fish", "patzer" or "woodpusher".
Dynamism: A style of play in which the activity of the pieces is favoured over more positional considerations, even to the point of accepting permanent structural or spatial weaknesses. Dynamism stemmed from the teachings of the 'Hypermodern movement' and challenged the dogma found in more classical teachings, such as those put forward by Wilhelm Steinitz and Siegbert Tarrasch.