Queen's Indian Defense

The Queen's Indian Defense (QID) is an "Indian Defense" chess opening defined by the moves:

1. d4 Nf6

2. c4 e6

3. Nf3 b6

The opening is a solid defense to the Queen's Pawn Game. 3...b6 increases Black's control over the central light squares e4 and d5 by preparing to fianchetto the queen's bishop, with the opening deriving its name from this maneuver. As in the other Indian defenses, Black attempts to control the center with pieces, instead of occupying it with pawns in classical style.

By playing 3.Nf3, White sidesteps the Nimzo-Indian Defense that arises after 3.Nc3 Bb4. The Queen's Indian is regarded as the sister opening of the Nimzo-Indian, since both openings aim to impede White's efforts to gain full control of the center by playing e2–e4. Together, they form one of Black's most well-respected responses to 1.d4.

If Black does not wish to play the Queen's Indian in response to 3.Nf3, alternatives include: 3...d5, transposing to the Queen's Gambit Declined; 3...Bb4+, the Bogo-Indian Defense; and 3...c5, which typically leads to a Modern Benoni or a Symmetrical English.