Okay that makes sense but doesn t it go against the original way Fischer wanted to modify Chess960 In original Chess I have the option to either castle king side or queen side when there are only Rooks and King on the back rank But now if I have this start position of 946 or 947 I have to move a rook Are there official rules out there by FIDE or USCF that explain what to do here If we are to be faithful to the original Chess setup then castling must be allowed either way I would think Instead we now have to move a rook away in order to castle queen side and it s only for roughly 2 maybe more initial setups I think what you said should be explained in a new subsection of the castling rules Like in original chess I have people argue about En Passant and I have an official place I can point to and tell them that En Passant is a real move Now if 946 or 947 arise they may either try to do a null move or they may force me to move a rook if a null move is allowed This seems like either a flaw or something that should be outlined in the rules specifically If it is the case where the rook must move first then I think a new subsection should be added to explain this