Chess opening
The initial phase of a chess game, when players develop pieces, secure their kings, and contest control of the center.
Development (chess): The process of bringing pieces from their starting squares to active positions. Rapid development mobilizes pieces before the opening phase gives way to middlegame plans.
Chess move: A turn in chess in which a player moves one piece or pawn, or castles. An opening is built from successive moves by both players.
Sicilian Defence: An opening beginning 1.e4 c5, in which Black contests the center asymmetrically. It is a major response to 1.e4 and often leads to sharp, unbalanced positions.
Middlegame: The phase of a chess game after the opening and before the endgame, often involving direct plans and attacks. It follows the opening, as development gives way to more concrete maneuvering and tactics.
Center (chess): The four central squares of a chessboard: d4, e4, d5, and e5. Influence over these squares supports piece mobility and often determines opening plans.
Chess notation: A system for recording chess moves and positions, commonly using algebraic notation. Opening variations are published and studied as sequences of recorded moves.
Queen's Gambit: A chess opening beginning 1.d4 d5 2.c4, offering a pawn to challenge Black's center. It illustrates how an opening can contest central control through a pawn offer.
Endgame: The phase of a chess game in which few pieces remain and king activity becomes more important. Its priorities differ from the opening's focus on development and central influence.
King safety: The degree to which a king is protected from attack. Castling and careful pawn moves reduce the danger of an exposed king.
Pawn structure: The arrangement of pawns on a chessboard and the relationships among them. Opening pawn moves establish structures that shape later plans and weaknesses.