I have only played this game in single-player mode, but my sister loves this game when she plays it with a friend, so have that in mind...
The Baldurs Gate is a hack-n-slash type of game but with a nice touch in atmospere and sound. You walk around in a Tolkien-inspired world talking to dwarves, elves or humans. The enemies are everything you expect from a fantasy-world including trolls, dragons and dark-elves. The story is quite good and unfolds as you play, and it keeps you interested to continue slash away enemies in the dungeons.
The problem is the lack of variation in combat. Ok, you have a small upgrading system, but it all ends up with you buying a bigger sword and hacking some more bad guys.
No, the joy in this game is the feel of fantasy, the good sound and voice acting, and the ability to play together with a friend.
All which makes this game a little better than the average action-adventure. I give it a 6.