ECO C20
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.
28 named opening lines are classified under ECO code C20.
- Barnes Opening: Walkerling — 1.f3 e5 2.e4 Nf6 3.Bc4
- Bongcloud Attack — 1.e4 e5 2.Ke2
- Center Game — 1.e4 e5 2.d4
- English Opening: The Whale — 1.e4 e5 2.c4
- King's Pawn Game: Alapin Opening — 1.e4 e5 2.Ne2
- King's Pawn Game: Bavarian Gambit — 1.e4 e5 2.c4 d5
- King's Pawn Game: Beyer Gambit — 1.e4 e5 2.d4 d5
- King's Pawn Game: Clam Variation, King's Gambit Reversed — 1.e4 e5 2.d3 f5
- King's Pawn Game: Clam Variation, Radisch Gambit — 1.e4 e5 2.d3 Nf6 3.f4 Bc5
- King's Pawn Game: King's Head Opening — 1.e4 e5 2.f3
- King's Pawn Game: Leonardis Variation — 1.e4 e5 2.d3
- King's Pawn Game: MacLeod Attack — 1.e4 e5 2.c3
- King's Pawn Game: MacLeod Attack, Lasa Gambit — 1.e4 e5 2.c3 f5
- King's Pawn Game: MacLeod Attack, Norwalde Gambit — 1.e4 e5 2.c3 d5 3.Qh5 Bd6
- King's Pawn Game: Mengarini's Opening — 1.e4 e5 2.a3
- King's Pawn Game: Napoleon Attack — 1.e4 e5 2.Qf3
- King's Pawn Game: Philidor Gambit — 1.e4 e5 2.d4 d6 3.dxe5 Bd7
- King's Pawn Game: Tortoise Opening — 1.e4 e5 2.Bd3
- King's Pawn Game: Wayward Queen Attack — 1.e4 e5 2.Qh5
- King's Pawn Game: Wayward Queen Attack, Kiddie Countergambit — 1.e4 e5 2.Qh5 Nf6
- King's Pawn Game: Wayward Queen Attack, Mellon Gambit — 1.e4 e5 2.Qh5 Nc6 3.Bc4 Nh6 4.d3 g6 5.Qf3 f6 6.Ne2 d5
- King's Pawn Game: Weber Gambit — 1.e4 e5 2.d3 d5 3.exd5 c6 4.dxc6 Nxc6
- King's Pawn Opening — 1.e4 e5 2.b3
- King's Pawn Opening: Speers — 1.e4 e5 2.Qg4 Nf6 3.Qf5
- King's Pawn Opening: Van Hooydoon Gambit — 1.e4 e5 2.Qe2 Nc6 3.c3 Nf6 4.Nf3 Bc5 5.d4 exd4 6.cxd4 Nxd4
- Portuguese Opening — 1.e4 e5 2.Bb5
- Portuguese Opening: Miguel Gambit — 1.e4 e5 2.Bb5 Bc5 3.b4
- Portuguese Opening: Portuguese Gambit — 1.e4 e5 2.Bb5 Nf6 3.d4