Carcassonne is a real-time, multiplayer board game.
You can read more about the game rules here - Carcassonne rules (pdf)
Cities - 2 points / tile and pennant when completed, otherwise 1 point / tile and pennant.
Roads - 1 points / tile when completed
Cloisters - 1 point for each neighbouring tile, 9 points when completed
Fields - 3 points for each completed city on the field - only at the end of game
Cathedral - a city with a cathedral scores 3 points / tile if completed otherwise none
Inn - a road with an inn next to it scores 2 points / tile if completed otherwise none
Seven Castles is a Carcassonne spin-off game. In this game you build castles enclosed by walls and rivers.
Castle walls - 1 points / tile when completed or at the end of game. Castle walls can end at rivers.
Fields - 1 point / tile when closed by castle walls or rivers. They score 0 if not completed until end of game. There musn't be missign tiles (wholes) in the field.
Bridges - connect two fields. If your field has a bridge you also need to close the connected field to complete it.
Rivers - 1 point / tile when completed. If not completed they still score 1 point/tile at the end. Rivers are handled as a whole - they are not segmented like roads.
Cloisters - 1 point for each neighbouring tile, 9 points when completed.
Narrow Sea is a Carcassonne spin-off game.
In this game you build cities, sea and land. You have meeples and ships. Meeples can go on cities or land, ships can go on sea.
Cities - 2 points / tile when completed, otherwise 1 point at the end of game.
Islands - 1 point / tile when completed or at the end of game.
Sea - 2 point / tile when completed, otherwise 1 point at the end of game.
A sea also ends at a strait - straits are marked with a light blue dashed line.
Also in the case of a strait there are 2 possible positions on both sides of the strait.
Lighthouses - double the score of the island - 2 points/tile if completed, 0 otherwise.
City with inner citadel - scores 3 points/tile if completed, 0 otherwise.
You receive points for every game you win:
Mini - 1p, Base - 4p, Castles - 4p, Exp - 6p, Double base - 8p, Double exp - 12p.
Points can be converted to credits at the rate of 25 point / credit if you have bought any credits in the last 30 days."
Every player has her points displayed before her name in the Lobby.
If you quit before the end and you have already placed a tile you receive penalty points - the same amount as the reward points above.
Credits can be bought from Facebook for 12 cents -i.e 10 credits cost $1.2.
Credits are deduced only for finished games so if the owner of the game leaves before that no credit is charged.