In the Duchy of Scridite Eumfelem ruled by a Plutocracy, a character must undergo a Trial by combat.
He has been framed by A cult or brotherhood - bound by a mission and code - and if found guilty of Terrorism, his punishment will be Baleful Polymorph. The prisoner permanently changes into a small animal. One of my favourite D&D modules is Castle Amber. Wouldn’t it be a neat twist for the central garden to be the prison of several banished beings changed into the form of small animals? If the subjects fail their second saving throw, they even gain animal intelligence, in effect becoming just another creature in the garden.

Duchy - The dominion of a duke, who is the highest ranking noble not in the royal not in line of succession.
Plutocracy - Plutocracy is rule by the wealthy, or power provided by wealth. In a plutocracy, the degree of economic inequality is high while the level of social mobility is low. This can apply to a multitude of government systems, as the key elements of plutocracy transcend and often occur concurrently with the features of those systems.
Trial by combat - Fight to the death, winner is innocent