Editing Bughouse chess (section)

=== Captured pieces ===
A player capturing a [[chess piece|piece]] immediately passes that piece to their partner. The partner keeps these pieces in their reserve and may, on their turn, instead of playing a regular move, place one of these pieces on the board (as in [[shogi]] and [[crazyhouse]]), called ''dropping'' the piece. Pieces in reserve may be dropped on any vacant square, including squares where the piece delivers check or checkmate; however, [[pawn (chess)|pawns]] may not be dropped on the first or last {{chessgloss|rank}}. (A variant does not allow dropped pieces to deliver check.<ref>[https://www.schaakbond.nl/sites/default/files/userfiles/schaakbond/handboek/schaakregels/Reglement%20doorgeefschaak.pdf Reglement Doorgeefschaak ("Passing chess rules")] {{Webarchive|url=https://web.archive.org/web/20171023063950/https://www.schaakbond.nl/sites/default/files/userfiles/schaakbond/handboek/schaakregels/Reglement%20doorgeefschaak.pdf |date=2017-10-23 }}, retrieved February 7, 2022.</ref>) Dropped pawns may [[promotion (chess)|promote]], but all promoted pawns convert back to pawns when captured. In play over the board, a promoted pawn can be put on its side to indicate promotion.<ref>von Zimmerman (2006), p. 15</ref> A pawn placed on the second rank may move two squares on its first move, and, if it lands directly next to an enemy pawn, be captured [[en passant]]. A rook placed on the rook's typical starting square (a1, h1, a8, h8) may take part in [[castling]]. Each player must keep the reserve or stock pieces on the table in front of the board, always visible to all players of the game.