This is a spell which if not used with care, can cause serious damage to the economy. Casting False Coin on a pile of coins, regardless of which currency, creates five more stacks of said currency of the same worth. While it is said these coins are only temporary, they indeed are permanent, exact duplicates.
It is unknown what made the mages of Moonshade to create this spell, and also why it hasn't been used to cause serious inflation, as it is very easy to cast and cheap, compared to the possible gain.
|“|| When cast upon any coin, this spell creates five such coins in its place. However, the spell will fail when cast upon another such magically created duplicate.|
- In hindsight, that the guards at the Bull Tower explicitely want a Gold Bar from the Avatar actually does make sense. They probably know of this spell and are satisfied with a gold bar, as gold bars can't be replicated with it and thus retain their value.