Queen's Gambit Accepted

Black takes the pawn on c4, planning to give it back for free development and play against White’s centre.

It is reached after 4 moves: 1. d4 d5 2. c4 dxc4.

White is to move and has 29 legal moves. Over the next four moves — two for each side — the game can branch into 799,087 different games. Those games reach 267,822 different positions: most positions can be reached in more than one way, 3 on average.

The Lichess opening list names 60 further lines after this position, such as Normal Variation (3. Nf3) and Saduleto Variation (3. e4).

The same moves can be played in 2 different legal orders that all reach this position. For example 1. c4 d5 2. d4 dxc4, which starts as the English Opening.