So I get that they created the 'Caligari Sector' for the game. But why would there be a complete separate type of currency from standard imperial credits?
Guard units from all over the Imperium often kill time on long journeys gambling/betting on things between other regiments, as it's mentioned in several books.
Yes the do use commodities as well, but mostly they use... 'Imperial Credits'
Sounds small minded I know, but when the majority of the game is so awesome it kicks off my OCD seeing such a minor deviation from the lore.....