The setting is mediaeval Europe at the time of the Black Death. Players try to bring as much of their population through the plague as possible, while at the same time making sure that their opponents get their unfair share of rats. You can call on the help of characters from all classes - the king will let you into his castle (the only permanently safe place) if you come from a plague free region, the monk can shoo the rats into a neighbouring region, the witch can control which regions are hit the hardest (you had better make sure she is on your side), the knight can spread the plague into more distant regions, the farmer increases the population (and the risk of catching the Black Death) and the merchant can run away (but he can't hide).
Everybody starts off with 4 population cubes on the board. There is also a plague region from where the plague can spread, this is where the figure of the Black Death is standing (at the start of the game he can be put anywhere). A player has 3 actions he can take on his turn:
Action 1 is to take a class card. This is optional and the card can be taken from the table or from another player.
Action 2 is to place a population cube. You can place as many cubes in any region of your choice as there are rat tokens in that region (at the start of the game there is one rat token in each region). So if you have a region with 3 rat tokens on it you can place 3 cubes on it. This may be very tempting but the more people you have in that region when the rat token is turned over the greater the risk of plague breaking out. The rat tokens have a number on them and if the number of cubes is equal to or exceeds that number then the token takes effect. They also have a combination of other symbols indicating who is affected. It might mean that the player with the largest population loses one cube, all players with population on that region lose a cube, players with certain class cards lose a cube or any combination of these. So your population that was once strong and healthy could suddenly be wiped out of that region entirely!
Action 3 is to move the Black Death figure. He can only be moved into a neighbouring region unless you have the knight card, in which case he can move up to two regions away.
Once the 3 actions have been carried out, the plague breaks out. The active player places one rat token (if there is only 1 rat token in the plague region) or two rat tokens (if there are 2 or 3 rat tokens in the plague region) onto a neighbouring region (preferably one with lots of your opponent's population cubes!). Then the token on the plague region is turned over and its effects carried out. Once all the rat tokens have been used up or one player has all of his population cubes on the board, the players can use their class cards one last time and then all of the rat tokens are turned over and carried out. The winner is the player with the most cubes left on the game board after this final outbreak of the plague.
What I thought worked very well was the use of the class cards. Each class card has its own special benefit and the more class cards you have the more benefits you gain. However, it can have serious disadvantages too when the rat tokens are turned over, as the more cards you have, the more likely you are to lose population. As you can't voluntarily give up a card but only lose it when another player takes one away from you, you could find you're left with a whole bunch of cards at the end of the game when all the rat tokens are turned over - ouch!
This game has received mixed reviews so far which is understandable. The main concept of the game is based on the negative interaction between the players. For this reason I would not class this as a family game, I don't think that many children that can cope with being wiped off the board (in fact I know a few adults who would have problems with this)!
So all in all, I think this is a very entertaining game of strategy when played with the right group of people, probably the more the better (I have only played in a group of three people so far) and I will definitely be buying the Pied Piper expansion.
Just for information: there is no in-game text but the rules are written in German. However, trawling the web I found that you can get downloads of the English rules.