Click on the third or sixth rank to set the en passant target square.

Book: ∞ / 0

# move proof disproof
1 b4 0
2 g4 0
3 Bg7 0
4 Nf6 0
5 Rd8 0
6 a6 0
7 a5 0
8 Re8 0
9 Rb8 0
10 b6 0
11 Nh6 0
12 Rc8 0
13 Bh6 0