I had always thought that if someone triggers an Aoo from your having a greater reach (say your 10 ft. reach vs his 5 ft.) then stepping back 5 ft. will allow you to have a new Aoo should he close in again. Then I thought: "Wait a minute, doesn't your opponent taking a 5 ft. step to close into melee again not triggering Aoo because he only moved 5 ft.?"
What is the verdict?!
What is the verdict?!