RPGaDAY 2025 day 4 has the prompt “message”.
In my response to this, I pointed out how much harder this was in the mediaeval days on which the classic D&D world is based, and suggested timings for messengers, carrier pigeons and magical means of communication.
One of my readers got in touch to remind me about visual methods of communication over a distance, referring to the clacks of Discworld, so I thought it worth adding this update on ways of communicating at a distance.
Semaphore and other visual messaging-at-a distance
Let’s start with the classic fantasy novel, The Lord of the Rings. This features the beacons of Gondor, fires which are lit to communicate an invasion. Each beacon on a hill can be seen by another, which then also lights theirs, and so the message travels as quickly as it takes for each beacon to light enough to be visible – certainly faster than a galloping horse.
But beacons are a very limited means of communication – they are either lit or not, so can only really communicate one thing.
The Discworld novels introduced the clacks – a series of towers with shutters which can be open or closed, encoding messages which can be repeated in a similar way, thus getting transmitted over long distances at speed.
These were based on the semaphore towers which Napoleon made great use of. Invented in 1792 by Claude Chappe, these used pivoted indicator arms on top of towers to encode information, which could be strung into messages. The towers were built 5-20 miles apart, and had an observer with a telescope on each one. When an observer saw the arms of the next tower shifting, they could read the message, and then pass it on.
According to Wikipedia, a symbol could be transmitted from Paris to Lille (a distance of about 225km/140 miles) in 2 minutes and Paris to Lyon (about 450km/280 miles) in 9 minutes, and operators could manage 2-3 symbols per minute. There were 196 possible symbols, and 92 of these were used, two at a time, to reference messages in a code book – a total of 8646 basic words and phrases. Other countries developed similar systems.
Of course, for such semaphore towers, you needed to build the tower (or at least have a fairly substantial travelling “tower”), and have operators watching and re-transmitting. Which gets expensive. And since they work by line of sight, they are put out of operation by night and poor weather.
A more portable form of semaphore was developed with hand-held flags, where the position of the arms corresponded to a letter – I became familiar with this through the Arthur Ransome “Swallows and Amazons” series, though I never got proficient enough to be able to meaningfully communicate with it (nor had anyone to practice with). “Wigwag” was an alternative using a single flag which was waved, the patterns encoding letters in a similar style to morse code – this had the advantage it could be used with lights on the end of poles to communicate at night.
Ships communicated via means of flags run up the mast. Each flag had a particular meaning and letter, and this way the admiral could send commands to other ships in the fleet.
However, to transmit any such message over a significant distance (i.e. one which was further than line of sight) required a chain of operators to receive and forward the message, and so, while faster than horseback, would also be significantly more expensive as well.
Conclusion
Communicating at a distance requires more thought than we have to worry about nowadays, and is very seldom instantaneous. Remember this the next time your players want to just “send a message”.
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