In return for the pawn(s) Black takes over the  initiative thank to his better developed pieces.
1. e2e4  1... e7e5  2. g1f3  2... g8f6  3. b1c3  3... b8c6  4. f1b5  4... c6d4 Rubinstein's move is considered to be the most reliable weapon against the Four Knights. 5. b5c4  5... f8c5  6. f3e5  6... d8e7  7. e5f3 