Sacred 2:Ali Baba
In the Desert region, the Temple Guardian's class quest takes him to a remote cave in the southwest corner of the area. Inside the cave, there waits one Ali Baba and his gang of Forty Thieves. They are guarding a special key you need to complete the class quest.
There's only one tiny problem with this portrayal. In the original story which dates back to the middle ages, Ali Baba is not a criminal mastermind. He isn't even the leader of the gang. He's a wood cutter who overhears a gang of theives visiting their stash cave. The cave entrance is enchanted and you need the proper password to get in or out - "Open Simsim" - which was bastardized into English as the familiar "Open Sesame". The gang catch wind that Ali Baba has found their stash and has gotten into the cave, so they set out to assassinate him and his family.
An abbreviated, but thorough version of the tale can be found on Wikipedia.com