It is named after the medieval fortified town of Carcassonne in southern France, famed for its city walls.

The game has spawned many expansions and spin-offs, and several PC, console, and mobile versions.

When stationing a follower, the marker is placed upright on the feature to claim that feature, except for a field, where the follower is laid down instead to emphasize that fields are not scored until the end of the game; the follower's role depends on the feature claimed, changing from thief/highwayman (road) to knight (city), monk (cloister or monastery), or farmer (field).

At that time, all incomplete features (including fields) score points for the players with the most followers on them.

A player may complete a feature by drawing and placing a tile, claim it by stationing a follower on the newly placed tile, and receive the score for completing it all in the same turn, but the sequence of that turn means the player cannot redeploy the follower after it is returned to their stock.

[7]: 11–13 At the end of the game, when there are no tiles remaining, fields and all other claimed but incomplete features are scored.

In this example, followers are stationed on the board according to the capital first letter of the color name: "R"ed, "Y"ellow, "G"reen, "B"lue, and "P"urple, where purple is substituted for "B"lack to avoid confusion with blue.

The Green farmer in [C5] is at risk of being enclosed in a loop and cut off from any completed cities.

A tile played at [F6] would complete the surroundings for the blue monks at [E5] and [F5], scoring eighteen points for those followers.

However, that monk will score eight points (one for the cloister and seven for the surrounding tiles) at the end of the game.

Worse, the green knight follower in [H6] will not score any points and is stranded because the city will never be completed.

The version of the game currently in print includes the River and Abbot mini-expansions.

There is a substantial luck component to the game; however, good tactics greatly improve one's chances of winning.

Examples of tactical considerations include: The game has been used in education to teach geographical concepts.

[15] Several official expansions for Carcassonne have been published, which add numerous additional rules, tiles and new kinds of figures.

There is also a travel-sized version of the original game, Travel Carcassonne (Reise-Carcassonne), released in 2007.

[47] The first official Carcassonne World Championship was held at SPIEL in Essen, Germany, in 2006.

[50] Pantelis Litsardopoulos is the only other player to have won the World Championship on more than one occasion, having reached the final in five consecutive years.

Since 2020 the Mind Sports Olympiad have run open international tournaments in a similar format to the World Championships.

From the start of the second edition, in 2021, the WTCOC has been officially sanctioned by the publisher Hans Im Glück and World Championship organisers Spielezentrum.

[53][54] Beginning in 2023 the top 4 teams in the WTCOC have been able to send an extra participant to the World Championships in Germany.