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

Book: ∞ / 0

# move proof disproof
1 Rg8 0
2 Rb8 0
3 f5 0
4 Rf8 0
5 a5 0
6 Rd8 0
7 f6 0
8 Re8 0
9 Rh8 0
10 Rc8 0
11 a6 0