Demilucidian is a spoken and written sub-language of the Protolucidian languages. Demilucidian is a minority language with usage concentrated primarily in northeastern Illuminatia. The most significant populations of Demilucidian speakers are found within the Wolfgang Amadeus Megalopolitan Complex and in the vicinity of the cities of Beethoven and Für Elise.
Demilucidian—like all of the Protolucidian languages—is a constructed language that evolved from the greater Protolucidian language, which itself developed aboard the Lucidus mission. Demilucidian is the least-spoken of the four recognized Protolucidian sub-languages. The sub-language is natively spoken by approximately 1% of Illuminatia's population. 6% of Illuminatians—including native users—are able to understand written and verbal Demilucidian as well as write and speak the language. 12% of Illuminatians have at least a functional understanding of Demilucidian in either written or spoken form if not both. Mute Point, Inc is the sole linguistics institution charged with preserving the language and regulating its usage.
Demilucidian shares its closest linguistic relationship with the Quasilucidian sub-language, which is spoken on Illuminatia's Modal Peninsula. Demilucidian and Quasilucidian together form the lesser-spoken second branch of the Protolucidian linguistic tree, having evolved from a variation of the parent Protolucidian language spoken during the Lucidus mission on the Lucidus III ship. Descendants of the third multiversal duplication of Lucidus III survivors speak Demilucidian, while descendants of the first and second multiversal duplication of Lucidus III survivors speak Quasilucidian.
Demilucidian shares the least mutual comprehensibility with the other Protolucidian languages. Native speakers of Demilucidian are able to understand about 85% of spoken and written Quasilucidian. Demilucidian speakers are able to understand 60% of Protolucidian Major—the dominant Protolucidian language used most often in minority-language media and trans-sublanguage communication. Meanwhile, Protolucidian Major speakers understand only 30% of Demilucidian. Quasilucidian speakers fare better at approximately 75% comprehension.
Like all Protolucidian languages, Demilucidian is never used exclusively by its speakers. Demilucidian instead is spoken in complement of Illuminatia's common language, Glossa Communi, as a "home" language—spoken chiefly among family and familiar people in everyday informal interaction. Demilucidian is an unofficial language that is not recognized for use in commerce or civic and governmental matters. This personal, non-public usage has remained consistent throughout the evolution of the Protolucidian languages and continues to be the case to a less-consistent extent into the present day. Demilucidian is taught electively in a minority of schools in the Wolfgang Amadeus Megalopolitan Complex where most of the language's speakers reside. Teaching of Demilucidian in other regions of Illuminatia is rare. Demilucidian is broadcast on a handful of wireless and television outlets in regions where it is spoken, and is printed in only a couple of alternative publications in northeast Illuminatia.