Well... Pen and Paper is very similar as the infinity engine game, as they use the same basic rules. Except that the possibilities in a P&P game are only limited by you and your friend's imagination.
The Forgotten Realm (the world in wich The Baldur's Gate and Icewind Dale series take part, is a Pen and paper world. All that back story in those games (like the time of trouble, Elminster, Drizzt, Bhaal,...) is coming from the pen and paper game.
It's hard to describe a gaming session. But here is the best I can do. One player is the dungeon master. He play the role of the computer in a video game, he animate every Monsters and NPCs, and keep track of the rules and create the story and quests. The other player all create a character, just like in Baldur's Gate II. And then they interact with each others and the Dm's NPC, to solve the DM's quests and such. The only difference is that instead of the computer randomly generating your rolls, you actually roll some dices. And that playing with let's say, 4 friends, is a lot more fun than playing a computer games, they have a lot better Ai, and in most case, a better sense of humor too.
