Chess Opening Theory/1. d4/1...Nf6/2. c4/2...e6/3. Nf3/3...Bb4

Bogo-Indian Defence
Black plays Bb4+ and White must block against the check. If White plays Nc3, the opening transposes into a Nimzo-Indian Defence. If instead White decides to block the check with Bd2, the resulting complications are likely to cause an exchange of pieces. Positions tend to be roughly equal, with trades (and, consequently, draws) being very common.

Theory table
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'''1. d4 Nf6 2. c4 e6 3. Nf3 Bb4+'''