Assassin's Creed and RPG games

My nephew and I have been checking out the Assassin's Creed series. I really like the series, although I have to admit that I prefer the first one the best in that it was set before gunpowder and guns were introduced. I want to find a good high fantasy game set in a Tolkenian style world, but with the game play of the first Assassin's Creed game where I don't *HAVE* to fight majorly tough bad guys to play the game, and I can sneak about and enjoy exploring if I prefer to.

If someone wants to make a blend of Assassin's Creed with the 2nd Advanced Dungeons and Dragons game play rules, but without gunpowder --- I would not only buy the game, I would buy the game system needed to play it on!