The book is a translation of the original US-American version. It also contains articles from additional American sourcebooks and some new content, namely the adventure "Northern Latitude".
Additional User Summary:
The book does not contain the Mythos part of the original text and did not get the approval of Chaosium.
Background on Unauthorized Version
The rights for the German version of Call of Cthulhu were held by Laurin Verlag. In 1993 Laurin declared bankruptcy and the rights for the game went back to Queen Games. Queen did not want to produce the Call of Cthulhu Series and gave the rights to Ars Ludi. Ars Ludi published this version with a new layout and cover. Chaosium was did not approve the unauthorized transfer of rights to Ars Ludi and the game was taken off the shelves in 1996. The rights were given to Welt der Spiele.
Die Erschaffung eines Charakters (Building a Character)
Fertigkeiten und Spielmechanismen (Skills and Gameplay)