Old Lucerish is a language used for cryptic instructions and runes, particularly significant in Warrick’s journal, which contains instructions on how to use the wardstone.

Old Lucerish is described as a logosyllabic language, similar to Morrainian, and is considered a dead language, only readable by a few characters in the story, including Violet Sorrengail and Dain Aetos.

The ability to read and translate Old Lucerish is portrayed as a rare and valuable skill, used for deciphering important texts and runes, and is even utilized as a secret code between Violet and Dain during their childhood​​​​.