The Colle System
Build the same neat pyramid every game: Bd3, c3, Nbd2, O-O: then detonate it with e4. The Colle is the club player's dream: one plan, learned once, dangerous forever.
Step through the main line
The lines
The Colle-Koltanowski (e4 break)
1. d4 d5 2. Nf3 Nf6 3. e3 e6 4. Bd3 c5 5. c3 Nc6 6. Nbd2 Bd6 7. O-O O-O 8. dxc5 Bxc5 9. e4
The Colle-Zukertort (b3 & Ne5)
1. d4 d5 2. Nf3 Nf6 3. e3 e6 4. Bd3 c5 5. b3 Nc6 6. Bb2 Be7 7. O-O O-O 8. Ne5
vs an Early ...Bf5
1. d4 d5 2. Nf3 Nf6 3. e3 Bf5 4. Be2 e6 5. O-O Bd6 6. c4 c6 7. Nc3 Nbd7
vs the ...g6 Fianchetto
1. d4 Nf6 2. Nf3 g6 3. e3 Bg7 4. Bd3 O-O 5. O-O d6 6. c3 Nbd7 7. Nbd2 e5
How this guide is made: the lines and explanations come from the authored Strong Squares repertoire curriculum. Automated checks verify legal move sequences and required teaching fields. Independent chess-editor approval remains a private-preview release gate. Read the teaching method.