Chess on a really big board is a large chess variant invented by Ralph Betza in 1996. The rules are the same as in regular chess except for these changes:
Instead of a basic chessboard used the board 16 by 16. Therefore, starting position is changed.
Added 8 fairy pieces and 8 extra pawns.
Extended pawn movement: an unmoved pawn can move one step, up to the middle of the board (in the case of the 16×16 board, the eighth rank), or anything in between. Once it has moved for the first time, it can only make one step at a time. En passant can be done on any of the squares pawn has passed through.
In castling, the rook moves the same distance as it does in chess. Thus, the king moves further (to the space right behind the rook)
The 50-move rule becomes a 100-move rule.