Indian Defence

2.c4

2.c4 strengthens White's control of the center, particularly the important d5 square. It also allows White's queenside knight to develop to the active c3 square without blocking the c-pawn.

Black has a number of possibilities at this point:

• 2...e6 – This move is solid and flexible. Depending on how white plays, black will end up in a Queen's Indian, Nimzo-Indian, Bogo-Indian, Queen's Gambit Declined, Benoni, or a Catalan.
• 2...g6 – This tends to be more aggressive (and riskier), though still solid if one knows the important strategic points. Black has the choice to move into a King's Indian Defence (KID) (regardless of white's play) or possibly a Grünfeld if white plays 3. Nc3 and black wishes.
• 2...c5 – This will likely end up being a Benoni (often aggressive, risky), Benko-gambit (positional pawn sacrifice by black on queenside), a symmetrical English (a bit quieter, but active pieces), or even a Tarrasch QGD (active for both sides).
• 2...d6 – This is the so-called "Old Indian," and it can either transpose into a KID or follow less popular lines with a strategy similar to the KID.
• 2...e5 – The Budapest Gambit. It has a unique character and often allows black active play. White usually gives the pawn back eventually, and usually gets a slightly better position, but black can do well against the ignorant white player.
• 2...d5 – The Marshall Defence. This is not the best idea, though not an absolute trap. Several opening encyclopedias give this a clear advantage to white if played right.