ECO C40
ECO C00–C99 — Open Games and the French Defense: 1.e4 e6 and 1.e4 e5, from the Italian and Ruy Lopez to the King's Gambit.
40 named opening lines are classified under ECO code C40.
- Elephant Gambit — 1.e4 e5 2.Nf3 d5
- Elephant Gambit: Maróczy Gambit — 1.e4 e5 2.Nf3 d5 3.exd5 Bd6
- Elephant Gambit: Paulsen Countergambit — 1.e4 e5 2.Nf3 d5 3.exd5 e4
- Elephant Gambit: Wasp Variation — 1.e4 e5 2.Nf3 d5 3.Nxe5 dxe4 4.Bc4 Qg5
- Gunderam Defense — 1.e4 e5 2.Nf3 Qe7
- King's Knight Opening — 1.e4 e5 2.Nf3
- King's Pawn Game: Busch-Gass Gambit — 1.e4 e5 2.Nf3 Bc5
- King's Pawn Game: Busch-Gass Gambit, Chiodini Gambit — 1.e4 e5 2.Nf3 Bc5 3.Nxe5 Nc6
- King's Pawn Game: Damiano Defense — 1.e4 e5 2.Nf3 f6
- King's Pawn Game: Damiano Defense, Damiano Gambit — 1.e4 e5 2.Nf3 f6 3.Nxe5 fxe5 4.Qh5+ g6 5.Qxe5+ Qe7 6.Qxh8
- King's Pawn Game: Damiano Defense, Damiano Gambit, Chigorin Gambit — 1.e4 e5 2.Nf3 f6 3.Nxe5 Qe7 4.Nf3 d5
- King's Pawn Game: Gunderam Defense, Gunderam Gambit — 1.e4 e5 2.Nf3 Qe7 3.Bc4 f5
- King's Pawn Game: Gunderam Gambit — 1.e4 e5 2.Nf3 c6
- King's Pawn Game: La Bourdonnais Gambit — 1.e4 e5 2.Nf3 Qf6 3.Bc4 Qg6 4.O-O
- King's Pawn Game: McConnell Defense — 1.e4 e5 2.Nf3 Qf6
- Latvian Gambit — 1.e4 e5 2.Nf3 f5
- Latvian Gambit Accepted — 1.e4 e5 2.Nf3 f5 3.exf5
- Latvian Gambit Accepted: Bilguer Variation — 1.e4 e5 2.Nf3 f5 3.Nxe5 Qf6 4.d4 d6 5.Nc4
- Latvian Gambit Accepted: Bronstein Attack — 1.e4 e5 2.Nf3 f5 3.Nxe5 Qf6 4.d4 d6 5.Nc4 fxe4 6.Be2
- Latvian Gambit Accepted: Bronstein Gambit — 1.e4 e5 2.Nf3 f5 3.Nxe5 Qf6 4.d4 d6 5.Nc4 fxe4 6.Qh5+ g6 7.Qe2
- Latvian Gambit Accepted: Foltys Variation — 1.e4 e5 2.Nf3 f5 3.Nxe5 Qf6 4.Nc4 fxe4 5.d3
- Latvian Gambit Accepted: Foltys-Leonhardt Variation — 1.e4 e5 2.Nf3 f5 3.Nxe5 Qf6 4.Nc4
- Latvian Gambit Accepted: Leonhardt Variation — 1.e4 e5 2.Nf3 f5 3.Nxe5 Qf6 4.Nc4 fxe4 5.Nc3
- Latvian Gambit Accepted: Main Line — 1.e4 e5 2.Nf3 f5 3.Nxe5 Qf6 4.d4
- Latvian Gambit Accepted: Nimzowitsch Attack — 1.e4 e5 2.Nf3 f5 3.Nxe5 Qf6 4.d4 d6 5.Nc4 fxe4 6.Ne3
- Latvian Gambit: Behting Variation — 1.e4 e5 2.Nf3 f5 3.Bc4 fxe4 4.Nxe5 Qg5 5.Nf7 Qxg2 6.Rf1 d5 7.Nxh8 Nf6
- Latvian Gambit: Corkscrew Countergambit — 1.e4 e5 2.Nf3 f5 3.Bc4 fxe4 4.Nxe5 Nf6
- Latvian Gambit: Corkscrew Gambit — 1.e4 e5 2.Nf3 f5 3.Nxe5 Nf6 4.Bc4 fxe4 5.Nf7 Qe7 6.Nxh8 d5
- Latvian Gambit: Diepstraten Countergambit — 1.e4 e5 2.Nf3 f5 3.c4
- Latvian Gambit: Fraser Defense — 1.e4 e5 2.Nf3 f5 3.Nxe5 Nc6
- Latvian Gambit: Greco Variation — 1.e4 e5 2.Nf3 f5 3.Nxe5 Qe7
- Latvian Gambit: Lobster Gambit — 1.e4 e5 2.Nf3 f5 3.g4
- Latvian Gambit: Mason Countergambit — 1.e4 e5 2.Nf3 f5 3.d4
- Latvian Gambit: Mayet Attack — 1.e4 e5 2.Nf3 f5 3.Bc4
- Latvian Gambit: Mayet Attack, Morgado Defense — 1.e4 e5 2.Nf3 f5 3.Bc4 Nf6
- Latvian Gambit: Mayet Attack, Poisoned Pawn Variation — 1.e4 e5 2.Nf3 f5 3.Bc4 fxe4 4.Nxe5 Qg5 5.d4 Qxg2
- Latvian Gambit: Mayet Attack, Polerio-Svedenborg Variation — 1.e4 e5 2.Nf3 f5 3.Bc4 fxe4 4.Nxe5 d5
- Latvian Gambit: Mayet Attack, Strautins Gambit — 1.e4 e5 2.Nf3 f5 3.Bc4 b5
- Latvian Gambit: Mlotkowski Variation — 1.e4 e5 2.Nf3 f5 3.Nc3
- Latvian Gambit: Senechaud Gambit — 1.e4 e5 2.Nf3 f5 3.b4