Like others have said, they fit, but if the manual is a thick one it might have a slight bend to it. Nothing harmful that would cause any permanent bending, however, but yeah, all my SNES manuals are in the UGC along with their respective games. I guess you could alleviate the bend if you file down some of the plastic holders but that's really not necessary IMO. Even a thick manual like Quest of the Avatar (NES) or Illusion of Gaia (SNES) fit just fine.