I recently bought a copy of Modern Warfare 3 for xbox from an online retailer that sells imported games, my console is PAL but the game is NTSC and works fine on my console. Does this mean that these copies of the game (the same ones I have) are region free? Also, will having an NTSC version of the game affect downloading DLC? Thanks.

EDIT: I looked around on google and found that some sites such as play-asia ( [ Register or Signin to view external links. ] ) sold 'region free' copies of MW3 so maybe MW3 is completely region free?