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How to implement 'en passant' when pawns can move three steps in its
first move? In Cazaux's implementation of Wildebeest Chess the pawn can
only be taken 'en passant' if it stops beside the enemy pawn. Although
it can be captured in passing if it stops both on fourth or fifth rank, it
cannot be captured if it stops on fifth rank and the enemy pawn is on the
fourth rank.

The description of Wildebeest Chess says only: 'On all passed squares,
the pawn can be taken en-passant.' So I suppose that it should be
possible to capture the pawn if it stops on the fifth rank and the enemy
pawn is on the fourth rank, then? Or is the 'en passant' rule contingent
on the fact that the pawn stops on the same rank as the enemy pawn?
/Mats