The Open Game is the family of openings beginning 1.e4 e5, the classical double king pawn openings such as the Italian Game, Ruy Lopez, and Scotch.
When both players push their king pawns two squares, the game enters the oldest and most classical territory in chess. The Open Games include the Italian Game, the Ruy Lopez, the Scotch, the Four Knights, and the romantic gambits like the King's Gambit and Evans Gambit that dominated the nineteenth century.
The name describes the character: with the central tension around e4 and e5, lines and diagonals tend to open early, development races matter, and tactical contact starts fast. The f7 and f2 squares come under quick fire, and a single slow move can hand the opponent the initiative outright.
This is why teachers have prescribed 1.e4 e5 to improving players for over a century. Open Games punish slow development instantly, so they train the fundamentals: rapid piece play, king safety, and tactical alertness. Strictly speaking the classification is about the opening moves; a particular Open Game can still turn into a blocked maneuvering battle, as many closed Ruy Lopez lines do.
Everything starting 1.e4 e5: the Ruy Lopez, Italian Game, Scotch, Four Knights, Petroff, King's Gambit, Vienna and more. Openings where Black meets 1.e4 with another move are Semi-Open Games instead.
Because the resulting positions reward exactly the habits improving players need: develop fast, castle early, watch f7 and f2, and calculate concrete threats. The lessons transfer to every other opening you learn later.
BetterChess is a practice tool — we make no guarantee you'll reach 1800 or any rating. Definitions are standard chess terminology; every diagram position is checked legal with the same engine the board runs.