The base game by Nils Hintze is set in Sweden, while the "Mythic Britain and Ireland" expansion by Graeme Davis is set in England, Wales, Scotland, and Ireland.

[4][1] The "Mythic Britain and Ireland" expansion was funded on Kickstarter in December 2021.

[5][1] The "Lost Mountain Saga" expansion by Ellinor DiLorenzo, which returns to the core game's Swedish setting, was announced in June 2023.

[6] The title Vaesen is a transliteration of the Swedish term väsen (pronunciation ett väsenⓘ), meaning a supernatural being or creature in both singular and plural, where ae is the common international transliteration of the letter ä.

It is cognate with the Danish and Norwegian terms væsen and vesen, which have the same meaning.