User blog comment:SupremeAssassin/Assassin's Creed 3: Combat System/@comment-117.193.246.8-20120530174153/@comment-5088097-20120531172742

Actually there is a regenerative health system now, they have taken away the health systems from AC2, ACB and ACR. On Mentor difficulty, the enemies would be harder to defeat, faster to attack you, it would be more difficult to sneak by guards which would prompt you to blend into the crowds. Master Assassin difficulty should a basic version of Mentor difficulty. Technically, I don't think Ubisoft will have this though.