Fictional currency

Its printed notes were verifiable by scanning with a device called a "fake meter", the function of which comprised a critical theme of the second book in the series, The Killing Machine.

The long-term value of currency is an issue in works featuring journeys through time or the lapse of very long periods (for instance due to the deep sleep or cryopreservation of the protagonists).

In some cases, compound interest may swell small amounts into a fortune, as happens in the Hitchhiker's Guide to the Galaxy by Douglas Adams, When the Sleeper Wakes by H. G. Wells, and the Futurama episode "A Fishful of Dollars".

[1] In utopian fiction, a money-free economy may still need a unit of exchange: in The Great Explosion by Eric Frank Russell, the Gands use favor-exchange based on "obs" (obligations).

[10] The use of "credits" is particularly common in futuristic settings, so much so that Sam Humphries has pointed it out as a cliché: "In any science-fiction movie, anywhere in the galaxy, currency is referred to as 'credits.