Opening family
Rat Defense Lines and Variations
The Rat Defense family contains 11 named lines in this opening book, spanning ECO A41 to C00. Use this page as the map, then open individual lines for exact move orders and diagrams.
How to study this family
White
White should use the move order as a checkpoint: finish development, identify the central break, and compare the continuations below before memorizing moves.
Black
Black should ask what White is threatening in the center, then choose development moves that prepare a clean pawn break or a useful exchange.
Start with the shortest line, then branch to the variations that change the pawn structure or tactical target. Memorizing every branch before understanding the family plan is usually wasted work.
Main named lines
- B00 · Rat Defense: Harmonist
- B00 · Rat Defense: Petruccioli Attack
- B00 · Rat Defense: Spike Attack
- A41 · Rat Defense: English Rat
- A82 · Rat Defense: Balogh Defense
- B00 · Rat Defense: Antal Defense
- C00 · Rat Defense: Small Center Defense
- A41 · Rat Defense: English Rat, Lisbon Gambit
- A41 · Rat Defense: English Rat, Pounds Gambit
- B00 · Rat Defense: Fuller Gambit
- B06 · Rat Defense: Accelerated Gurgenidze
Deep theory branches
- 1. d4 d6 2. c4 e5 3. dxe5 Nc6 — Rat Defense: English Rat, Lisbon Gambit
- 1. d4 d6 2. c4 e5 3. dxe5 Be6 — Rat Defense: English Rat, Pounds Gambit
- 1. e4 d6 2. f4 d5 3. exd5 Nf6 — Rat Defense: Fuller Gambit
- 1. e4 g6 2. d4 d6 3. Nc3 c6 — Rat Defense: Accelerated Gurgenidze
- 1. d4 d6 2. c4 e5 — Rat Defense: English Rat
- 1. e4 d6 2. d4 f5 — Rat Defense: Balogh Defense
- 1. e4 d6 2. d4 Nd7 — Rat Defense: Antal Defense
- 1. d4 e6 2. e4 d6 — Rat Defense: Small Center Defense
- 1. e4 d6 2. f4 — Rat Defense: Harmonist
- 1. e4 d6 2. h4 — Rat Defense: Petruccioli Attack
- 1. e4 d6 2. g4 — Rat Defense: Spike Attack