Clacks

The clacks, often written as The Clacks, is a fictional long-distance communications network from Terry Pratchett’s Discworld series. It consists of a chain of semaphore towers connected across the realm, allowing textual messages to be transmitted quickly between distant locations. The term derives from the characteristic clacking sound of the signaling arms and mechanical components as messages are passed along the line.

Operation centers on trained operators at each tower who convey letters or short phrases by arm positions or flag signals. A message is encoded at the origin, relayed from tower to tower, and reconstructed at the destination. The system is designed for speed relative to handwritten letters and courier routes, but it relies on the integrity of the entire chain; a single damaged link can disrupt or delay transmission. In practice, messages may be printed or otherwise delivered to recipients once the signal reaches the endpoint.

Historically, the Clacks emerges as a merchant- and state-supported infrastructure to accelerate communication and commerce on the Discworld. It gives substantial power to those who control or manipulate the network, especially the Clacksmen guilds and their patrons, and it interacts with other media, such as the printing and newspaper trades, shaping information flow and political influence.

In the novels, the Clacks is depicted as both a technological achievement and a focal point for debates about speed, reliability, censorship, and information control. Its portrayal emphasizes the social consequences of rapid communications: the benefits of immediacy alongside the risks of miscommunication, monopoly power, and manipulation.