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

Book: ∞ / 0

# move proof disproof
1 f5 0
2 c5 0
3 Nc6 0
4 Na6 0
5 c6 0
6 a5 0
7 Ba6 0
8 Ke7 0
9 Kd6 0
10 Kd8 0
11 Ke8 0
12 Bb7 0
13 Kc6 0
14 a6 0
15 Ke6 0