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

Book: ∞ / 0

# move proof disproof
1 f5 0
2 e5 0
3 Ke6 0
4 Kc6 0
5 Ke8 0
6 a5 0
7 Kd6 0
8 Bg7 0
9 f6 0
10 Bb7 0
11 e6 0
12 h5 0
13 Nf6 0
14 c5 0
15 Ra7 0
16 Nc6 0
17 Qe8 0
18 c6 0