Rat Defense is the name of multiple chess openings:
- Rat Defense, Balogh Defense: 1. d4 d6 2. e4 f5
- Rat Defense, Accelerated Gurgenidze: 1. e4 g6 2. d4 d6 3. Nc3 c6
- Rat Defense, Antal Defense: 1. d4 d6 2. e4 Nd7
- Rat Defense, English Rat: 1. d4 d6 2. c4 e5
- Rat Defense, Norwegian Rat: 1. e4 g6, 2. d4 Nf6
- Rat Defense, Harmonist: 1. e4 d6 2. f4
- Rat Defense, Fuller Gambit: 1. e4 d6 2. f4 d5 3. exd5 Nf6
- Rat Defense, Petruccioli Attack: 1. e4 d6 2. h4
- Rat Defense, Spike Attack: 1. e4 d6 2. g4
- Rat Defense, Small Center Defense: 1. d4 d6 2. e4 e6