Right now I've got an REP loop that alternates turns, and validates moves for rook, bishop, queen, and knight. It, however, doesn't yet: 1. Validate the other pieces (king, pawn, castling, en-passant, promotion). 2. Recognize check, mate, or stalemate. If I don't finish by the 17th... uh... extension? :) Otherwise, I'll just send my partial solution. Thanks, Devin