There are no 0 or 1 ply gambits.
2-ply gambits:
Englund Gambit 1.d4 e5
Old Benoni: 1.d4 c5
Jaenisch Gambit: 1.c4 b5
From Gambit: 1.f4 e5
Ross Gambit: 1.Nf3 e5
Duras Gambit: 1.e4 f5
3-ply Gambits:
King's Gambit: 1.e4 e5 2.f4
Queen's Gambit: 1.d4 d5 2.c4
Blackmar-Diemer Gambit: 1.d4 d5 2.e4
Réti Gambit: 1.Nf3 d5 2.c4
Réti: Wing Gambit: 1.Nf3 c5 2.b4
English: Wing Gambit: 1.c4 c5 2.b4
Sicilian:Wing Gambit: 1.e4 c5 2.b4
Gibbins-Weidenhagen Gambit: 1.d4 Nf6 2.g4
Zilbermints-Benoni Gambit: 1.d4 c5 2.b4
Omega Gambit: 1.d4 Nf6 2.e4
Staunton Gambit: 1.d4 f5 2.e4
Krejcik Gambit: 1.d4 f5 2.g4
Alekhine: Krejcik: 1.e4 Nf6 2.Bc4
John Tracy Gambit: 1.e4 Nf6 2.Nf3
Wagner-Zwitersch Gambit: 1.f4 f5 2.e4
Wade Gambit: 1.c4 f5 2.g4
Hickmann Gambit: 1.c4 f5 2.e4
Wheeler Gambit: 1.e4 Nc6 2.b4
Grob Gambit: 1.g4 d5 2.Bg2
More-ply gambits will be added later.
If I missed something, please post and I'll add.
2-ply gambits:
Englund Gambit 1.d4 e5
Old Benoni: 1.d4 c5
Jaenisch Gambit: 1.c4 b5
From Gambit: 1.f4 e5
Ross Gambit: 1.Nf3 e5
Duras Gambit: 1.e4 f5
3-ply Gambits:
King's Gambit: 1.e4 e5 2.f4
Queen's Gambit: 1.d4 d5 2.c4
Blackmar-Diemer Gambit: 1.d4 d5 2.e4
Réti Gambit: 1.Nf3 d5 2.c4
Réti: Wing Gambit: 1.Nf3 c5 2.b4
English: Wing Gambit: 1.c4 c5 2.b4
Sicilian:Wing Gambit: 1.e4 c5 2.b4
Gibbins-Weidenhagen Gambit: 1.d4 Nf6 2.g4
Zilbermints-Benoni Gambit: 1.d4 c5 2.b4
Omega Gambit: 1.d4 Nf6 2.e4
Staunton Gambit: 1.d4 f5 2.e4
Krejcik Gambit: 1.d4 f5 2.g4
Alekhine: Krejcik: 1.e4 Nf6 2.Bc4
John Tracy Gambit: 1.e4 Nf6 2.Nf3
Wagner-Zwitersch Gambit: 1.f4 f5 2.e4
Wade Gambit: 1.c4 f5 2.g4
Hickmann Gambit: 1.c4 f5 2.e4
Wheeler Gambit: 1.e4 Nc6 2.b4
Grob Gambit: 1.g4 d5 2.Bg2
More-ply gambits will be added later.
If I missed something, please post and I'll add.