The Queen's Indian developed within the hypermodern exploration of the early twentieth century and gained a strong place in master practice during the following decades. Its central idea is restraint through pieces: Black prepares a queenside fianchetto and contests e4 without immediately establishing a pawn on d5. The name distinguishes that bishop development from the kingside fianchetto of the King's Indian.
A typical starting point is 1.d4 Nf6 2.c4 e6 3.Nf3 b6. The knight on f6 and a future bishop on b7 can both influence e4. White's choice of Nf3 also explains the opening's traditional relationship with the Nimzo-Indian: without a knight on c3, Black does not have the same pinning opportunity with ...Bb4.
White can fianchetto the king's bishop, prepare a central expansion or use a3 to influence Black's bishop choices. Black may develop the bishop to b7 or use ...Ba6 in suitable lines. These variations are not interchangeable. The position of White's queen, knight and central pawns affects whether a bishop move creates useful pressure or simply spends time.
Start with the Classical Fianchetto and compare the influence of both long-diagonal bishops. Ask when either side can change the central pawn structure without losing control of key squares. The opening became a dependable repertoire option because its development has a clear strategic foundation, but converting that foundation into good moves still requires attention to the opponent's exact setup.
Try this at the board
Locate every Black piece or future piece influencing e4, and explain why White's third move matters.