Are Guild Wars: Factions and Guild Wars: Nightfall expansions of the original game? Or are they able to work alone.
Stand-alone. No GW chapter requires any other chapter to be installed in order to work.
The way the system works, is that if you buy a second chapter, an option will be presented after logging in to the game to add the extra chapter's CD key to your account.
I don't know how, and I don't know why, but this is totally Sheep's fault.
Oh okay thanks :).