Glossary of Chess

Gambit: A sacrifice (usually of a pawn) used to gain an early advantage of space and /or time in the opening.
Game score: The record of a game in some form of notation. In over-the-board tournaments, the game score is recorded on a score sheet.
GM: abbreviation for Grandmaster.
Good bishop: A bishop which has high mobility, typically because the player's pawns are on squares of color opposite to that of the bishop. (See #Bad bishop.)
Grandmaster: The highest title a chess player can attain (besides World Champion). When used precisely, it is the title awarded by FIDE starting in 1950, but it can be used to describe someone of comparable ability. The term International Grandmaster or IGM would refer only to the FIDE title.
Grandmaster draw: A game in which the players quickly agree to a draw after making little or no effort to win. This may be a very boring game, e.g. 1.d4 d5 2.c4 c6 3.cxd5 cxd5 4.Nc3 Nf6 5.Nf3 Nc6 6.Bf4 Bf5 7.e3 e6 Draw Agreed, or a superficially exciting game played with a variation the players know leads to a draw, e.g. 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Bxc6 dxc6 5.0-0 Bg4 6.h3 h5 7.c3 Qd3 8.hxg4 hxg4 9.Nxe5 Bd6 (a pseudo-sacrifice of Black's queen) 10.Nxd3 Bh2+ 11.Kh1 Bd6+ and Black draws by perpetual check. Although originally used to refer to such games between grandmasters, the term is now used colloquially to refer to any such game.
Greek gift sacrifice: Also known as the classical bishop sacrifice, it is a typical sacrifice of a bishop by White playing Bxh7+ or Black playing Bxh2+ against a castled king to initiate a mating attack.