The Queen's Indian is both open and asymetrical, making it feel similar to the Sicilian, although the actual moves are very different.

The Queen's Indian is fairly conservative for black (with the exception of the early knight attack), but white's play is unusual in three ways; first, the 'd4' opening, second, the kingside bishop on the long diagonal, and thirdly, the early queen activity.

An investigation of variations should also include a look at the "Nimzo-Indian".