Citadels: Price of the poorhouse from Dark City
In the US version, the Poor House costs 5 gold. In European versions, it costs 0 gold. The general consensus is that you should play the Poor House with its face value. If your version says 0 cost, that's what you should play it as. If you don't want to do that, make sure you inform everyone about this before the game starts.

It's not clear which publisher is in error, as the creator of the game, Bruno Faidutti, never spoke on the subject.

There are a lot of inconsistencies between European and US versions of Citadels. Someone on BGG once claimed that the 0 cost version is a misprint, but as far as I could tell they had no official source for that information, and it caused a bit of debate.