The story and setting of Divine Divinity are typical of what you'd expect from a fantasy role-playing game. The land of Rivellon combines magic, monsters, and medieval sensibility under one roof and is populated not just by humans but also by dwarves, elves, orcs, the living dead, and other fantasy archetypes. That the game takes place in an immediately recognizable fantasy world is evidence that Larian Studios didn't take risks with every aspect of Divine Divinity. The designers were wise in this--if you've played other role-playing games before, then chances are it won't take you long to get accustomed to Divine Divinity, and you'll appreciate that.
You'll appreciate even more the massive amount of detail that lies underneath the game's superficially generic style. This is one of those uncommon role-playing games where the world actually seems rather alive. Political tensions, social disorder, secret factions, and various guilds, cults, and pockets of resistance can be found all throughout Rivellon, and in large part it's up to you to decide whether or not to involve yourself in any of it. Alternately, you could just as well roam the countryside slaying villains and other wicked creatures, earning riches and using them to buy better and better equipment. The game does have a cohesive central story to it, but like many classic computer RPGs, Divine Divinity is just as much about creating your own adventures as it is about following a linear plot.