Nimzo-Indian Defense

The Nimzo-Indian (1.d4 Nf6 2.c4 e6 3.Nc3 Bb4) is one of the most respected Black openings in chess. Named after Aron Nimzowitsch, who pioneered it in the 1920s, it ignores classical principles - Black doesn't contest the centre with pawns, but instead pins the c3 knight to disrupt White's structure. The Nimzo is the favourite of every world champion since Capablanca who has played 1...Nf6.

Main line: Rubinstein (4.e3)

After 4.e3, White unpins the bishop indirectly and develops calmly. Black usually plays 4...O-O or 4...c5, and the game becomes a structural battle: if Black ever trades on c3 (...Bxc3 bxc3), White gets doubled pawns but the bishop pair and a strong centre. The whole opening is about whether Black can punish those doubled pawns before White's bishops dominate.

Variations

Classical (4.Qc2)

White moves the queen to c2 to prevent doubled pawns - if Black plays ...Bxc3 now, White recaptures with the queen. The cost: White's queen is exposed early and Black gets time to develop. The most testing line: 4...O-O 5.a3 Bxc3+ 6.Qxc3 b6 with ...Bb7 and ...d6 to come, a slow positional setup that's perfectly fine for Black.

Sämisch (4.a3)

White voluntarily accepts the doubled pawns. After 4.a3 Bxc3+ 5.bxc3, White has c-pawns on c3, c4, but also the bishop pair and a free hand to play f3-e4 building a huge centre. The sharpest test of the Nimzo - if you don't know the resulting middlegame structures, White's pawns roll over you.

Leningrad (4.Bg5)

A modern try. White pins the f6 knight, asking Black to either accept the pin or trade with ...h6 / ...Bxc3+. Less popular than Rubinstein or Classical but practical - many Nimzo specialists don't know it as well as the main lines.

Common traps

Don't move ...Bxc3 too early in the Classical: in 4.Qc2 lines, capturing on c3 lets White recapture with the queen and develop with a3, Bg5, e3, Bd3 - a clean position. Hold the bishop on b4 and only trade when concrete - usually when forced by a3, or in exchange for something specific.

Beware of e4 breaks: in the Rubinstein, if Black doesn't play ...d5 at the right moment, White can build a huge centre with e4. Once e4 lands, the bishop on b4 becomes purposeless because the pin is no longer useful - the knight on c3 has fulfilled its mission.

Typical plans for Black

Black has three main structural plans depending on which White system appears. Against the Rubinstein, play ...d5 and ...c5 to challenge the centre, often heading into an isolated-queen-pawn position. Against the Classical, play ...b6, ...Bb7, ...d6, ...c5 - a slow setup that targets c4 and waits for White's queen to commit. Against the Sämisch, play ...d6, ...e5, and aim for piece play to exploit the doubled pawns.

The Nimzo is the most flexible Black opening against 1.d4 - one tool that handles many White tries. The drills below cover the three main systems.