Dungeon Siege Character Races

• In DS2 multiplayer you play the single-player campaign, the only difference being you are playing with other people.
• You aren't limited to only controlling 1 character per player - 2 players can have 3 characters each for example (not sure if those are the correct numbers though).
• You can save the state of the multiplayer campaign and resume it later.
• Every player gets his own quest rewards.

One thing didn't change, though: you can use a single-player-campaign raised character in multiplayer, but not the other way around.

Run the DSVideoConfig.exe in the installation directory, and explicitly select your video card (rather than the default "Primary Display Driver - Hardware" or "TnL").

Also, it looks like an additional step is needed for Legend of Aranna to work. Copy the first line from the DungeonSiege.ini file in the Dungeon Siege folder to the DungeonSiege.ini file in the LoA folder.

(Source)