The term King's Pawn Game refers to any chess opening starting with the move
- 1. Opening theory in chess/1. e4
White opens with the most popular of the twenty possible opening moves. Since nearly all of these openings have names of their own, the term "King's Pawn Game", unlike Queen's Pawn Game
, is rarely used to describe the opening of the game.
Advancing the king's pawn up two squares is highly useful because it is an early stab for center and it frees the queen and bishop so that they can be developed. Chess legend Bobby Fischer has said the King's Pawn Game is the "best by test."
King's Pawn Games are further classified by whether Black responds with Opening theory in chess/1. e4/1...e5 or not. Openings beginning with Opening theory in chess/1. e4 Opening theory in chess/1. e4/1...e5 are called Double King's Pawn Games (or Openings), Symmetrical King's Pawn Games (or Openings), or Open Games—these terms are equivalent.
Openings where Black responds to Opening theory in chess/1. e4 with a move other than Opening theory in chess/1. e4/1...e5 are called Asymmetrical King's Pawn Games or Semi-Open Games.
The Encyclopaedia of Chess Openings classifies all King's Pawn Games into volumes B or C. Volume C is used if the game starts with Opening theory in chess/1. e4/1...e6 (the French Defence) or Opening theory in chess/1. e4 Opening theory in chess/1. e4/1...e5. Volume B is used if Black answers Opening theory in chess/1. e4 with any other move.
The rare instances where the opening does not fall into a more specific category than "King's Pawn Game" are included in codes B00, C20, and C50.
The Black responses which are given one or more chapters in the Encyclopedia of Chess Openings are given below, ranked in order of popularity according to ChessBase
- 1...c5 is the most common continuation, and is called the Sicilian Defence. The Sicilian Defence allows black to fight for the center by preparing to meet a d2-d4 advance with ...c5xd4. The Sicilian is among the sharpest and most analyzed openings in chess, and it has eighty chapters, B20-B99, set aside for it in ECO.
- 1...e5 leads to the classical Open Games, which includes openings like the Ruy Lopez, King's Gambit, Italian Game, Scotch Game and Petroff Defense. Also in this opening, Black is ready to meet a d2-d4 advance with e5xd4. These openings are covered in chapters C20-C99 in ECO.
- 1...e6 is the French Defence, covered in chapters C00-C19 in ECO. Black's restrained response allows White to play 2.d4, frequently with some advantage in space, but Black is usually prepared to lock up the center to defend against White's initiative and strike back with a c7-c5 advance.
- 1...c6 is the Caro-Kann Defence, covered in chapters B10-B19 in ECO. Like the French, this is also considered to be a solid reply, but Black will often need to surrender control over the center (e.g. after 2.d4 d5 3.Nc3 Black's main line is dxe4.) On the other hand, the light squared bishop will usually not wind up trapped behind its own pawns, as is common in the French.
- 1...d6 and,
- 1...g6 usually lead to similar openings called the Pirc Defense and Modern Defense. The openings allow White to build up a pawn center with 2.d4, but Black is preparing to bring a bishop to g7 and strike back at the center. These openings are covered in chapters B06-B09 in ECO.
- 1...Nf6 is the Alekhine Defense, which invites White to chase the knight with 2.e5. Black is often forced to spend time moving the knight several times as it is chased around the board, all the while allowing White to build up a pawn center. Black is aiming to prove that White's pawns are overextended and weak. The Alekhine is covered in chapters B02-B05.
- 1...d5, the Scandinavian Defense is a direct strike at the pawn at e4, forcing the situation in the center. After 2.exd5 Qxd5 however, Black loses time since the queen is developed early. The Scandinavian is covered in chapter B01 in ECO.
Apart from these eight responses, all other replies from Black are covered together in ECO chapter B00 ("Uncommon King's Pawn Opening"). A few of these are not entirely obscure, and have received extensive analysis.
Some other, rare, replies to 1.e4 have exotic names, but these are considered inferior and with a few exceptions, have not received significant and serious attention by masters.