Nimzo-Indian Defense: Rubinstein System, Rubinstein Variation, Main Line

1.d4 Nf6 2.c4 e6 3.Nc3 Bb4 4.e3 c5 5.Ne2 cxd4 6.exd4 O-O 7.a3

ECO E42

The Nimzo-Indian Defense: Rubinstein System, Rubinstein Variation, Main Line is a chess opening line in the Nimzo-Indian Defense complex, reached after 1.d4 Nf6 2.c4 e6 3.Nc3 Bb4 4.e3 c5 5.Ne2 cxd4 6.exd4 O-O 7.a3.

It is catalogued under code E42 in the Encyclopaedia of Chess Openings (ECO).

The defining move a3 is chosen by White on move 7.

Study this line with a grandmaster

This position is covered in the Nimzo-Indian Defense course: a GM-authored repertoire you study move by move, then practice against a human-like AI opponent.

Every chess term used here is defined in the chess terms glossary. Browse all opening courses or the full ECO code index.