The Witcher game is based on some novels written by Andrzej Sapkowski, the most popular fantasy author in Poland. Three of these books are already translated into english yet: The last Wish, Sword of Destiny and Blood of Elves. Much more short stories exists of the famous Witcher Geralt of Rivia, but they are only available in polish at this time.
Note:
The following description and all of my pages for "The Witcher" are related only to the PC-version of the game.
The game begins in Kaer Morhen, an old ruined fortress where the witchers live. Geralt of Rivia was nearly dead when the witchers found him and he has to learn all things again. During the following assault on the fortress the player learns through a tutorial how to fight and use his skills step by step. The player learns to know the other witchers here and it is a bit pity that in the rest of the game they never are shown again. I hope for the sequel they are included more somehow...
As in the books Geralt has to make decisions, decisions that are not just evil or good but are hanging somewhere between, because the world is not just depending on evil or good. It is a dark world Sapkowski settled his witcher-stories in and so is the game.
Elves and dwarves are only a secondary class, racism and violence is also included in the game like the fact that witchers are mutants and for this not very likely be seen. They are paid for slaying monsters and nobody wants to have other things to do with them.
The game also includes Geralts encounters with women, there is no sex shown but within the game he can collect "sexcards" with ...erh... nice pictures of those women. And now lets travel a bit further into the depths of the gamestory.
As mentioned before, you start with your main character Geralt in Kaer Morhen. After defeating the intruders and learning how the skills work you leave Kaer Morhen to find the stolen secrets of the witchers. Your way leads to Vizima, a dark city with all kinds of violence, racism and sex. And not to forget the enemies...
At some points Geralt has to make decisions, you as the player can decide whatever you think is best. The story goes on with Geralt searching for contracts to fulfill, slaying monsters to make money (as witchers do) and find out about the stolen secrets. You have to decide to fight along with the Scoia'Tael, a non-human rebelling group fighting for their rights, or you can fight with the "Order of the Flaming Rose" and cut off the revolts.
However, you have to go to many places to reach your own goal, you have to fight a sorcerer and his summoned monsters, you have to find out about a child which is telling about old prophecies, you encounter an old fishfolk named Vodyanoi and you have to fight against your destiny (or maybe not?).
However, the game has three different endings, you can try to stay neutral, or fight for one of the sides. Which is good and which is evil? Well, there is not a good and not an evil, it depends on your point of view if something is better than the other, that's all. That's true witchery...
Here you can find all news and reports about the Witcher, you can find screenshots, trailers, the Djinni Adventure Editor and a marketplace with fan-made modules for the Witcher. You can also have a look at The Witcher: Versus - Browsergame or visit the community forum:
CD Projekt Red - The Witcher