Vienna Game

Named after Vienna, where it was popular in the 19th century. White develops the queen’s knight first and often follows with f4.

It is reached after 3 moves: 1. e4 e5 2. Nc3.

Black is to move and has 29 legal moves. Over the next four moves — two for each side — the game can branch into 820,797 different games. Those games reach 272,438 different positions: most positions can be reached in more than one way, 3 on average.

The Lichess opening list names 58 further lines after this position, such as Max Lange Defense (2... Nc6) and Falkbeer Variation (2... Nf6).

The same moves can be played in 2 different legal orders that all reach this position. For example 1. Nc3 e5 2. e4, which starts as the Van Geet Opening.