At its release, Assassin's Creed II required a constant internet connection to play. Early community "cracks," such as the Server Emulator 21 or Server 11, functioned by tricking the game into connecting to a local server on your PC rather than Ubisoft's servers.
The need for these specific third-party cracks has diminished due to official updates and modern platform features: assassins creed 2 offline server 21 single file cracked
That being said, here's a detailed feature list of what this cracked version might entail: At its release, Assassin's Creed II required a
The "Assassins Creed 2 Offline Server 21 Single File Cracked" Version At its release