All attacking units must retreat to original territories from where they attacked, while defenders simply move to a adjacent freindly territory. Automatic retreats do not occur to Paratroopers, Amphibious Landings, or Commando raids. Defending units in a territory with a factory are exempt from retreating. Artillery and planes in air combat ignore auto retreats. After first attack you roll a D12 die after each round of combat for both sides and if you roll the numbers I posted in last post, you must retreat wether your attacking or defending. Sorry for not mentioning the defenders have to retreat in last post.