My idea is to have a 14 by 14 board with an 8 by 8 in the middle, so there are an additional 3 files/rows on each side. The king must stay within the 8 by 8 in the middle, but any other piece can go to the outside squares.
Pieces are set up normally on the middle 8 by 8 but can go to the other squares on the 14 by 14.
Pawns promote on the 8th rank of the inside 8 by 8
My idea is to have a 14 by 14 board with an 8 by 8 in the middle, so there are an additional 3 files/rows on each side. The king must stay within the 8 by 8 in the middle, but any other piece can go to the outside squares.
Pieces are set up normally on the middle 8 by 8 but can go to the other squares on the 14 by 14.
Pawns promote on the 8th rank of the inside 8 by 8