Be careful when buying a used game

When installing the game you will be (almost) forced to activate the registry key online.
Unchecked is the key, to get any updates / patches for the game. These are automatically installed on the so-called. Launcher once you start the game with an active online connection.
As already mentioned in several reviews, the patches are almost essential in order to give rise to full gaming fun (at least technically).

If the game is used, then it may be that the key is enabled even under the e-mail address of the previous owner. In this case, no second activation be carried out!

The following response I received on the subject also from Kalypso Support:
The key can be activated only once and when reselling the owner (seller) has to take care that dier Key is unlocked again. An activation can be only the owner of the Keys, the one on the e-mail address that is registered to make. If the previous owner can not be determined to replace the game with your dealer, since it is virtually unusable.