====== Chess - Programming - Polyglot Book Format - Enpassant ======

**Enpassant** is part of the [[Chess:Programming:Polyglot Book Format:Key|Key]]

It is the exclusive or of entries from the **RANDOM_ENPASSANT** sub-array.

  * The offset is the file of the double-pushed pawn resulting in enpassant (counted from 0(=a) to 7(=h)).

<WRAP info>
**NOTE:**  If this does not apply then enpassant=0.

This is different from the FEN standard.

  * In the FEN standard the presence of an "enpassant target square" after a double pawn push is unconditional.
  * It is irrelevant if the potential enpassant capturing move is legal or not.
    * Examples where it would not be legal are when the capturing pawn is pinned or when the double pawn push was a discovered check.

</WRAP>