From what I can glean, Anssi is right. The 1.13 patch is just for gameplay and fixes, the Mongol Expansion contains the new units, modes, etc, and the Warlord Edition is the original Shogun, the 1.13 update, AND the Mongol Expansion in one box. People who already have the game can download the patch for free, and the Mongol info from EX, and do not have to buy the Warlord Edition.

-- B)