In the Grand Duchy of Quares ruled by a Totalitarian, a character must undergo a Trial by combat.
He has been framed by A monster or group of monsters - mind flayers, a beholder, giants, a dragon - and if found guilty of Murder, his punishment will be Symbol of Death. Cast Permanency, place the symbol so its 60 foot radius crosses the only entrance. Cast Curse on the prisoner to lower their saving throw. This still gives the prisoner a chance at a saving throw, so you will want to target those with naturally poor Fortitude, and this is better as a deterrent than a cell because the desperate will take their unknown-but-poor chances of surviving, sometimes. Substitute other Symbols to create other defenses in the prison.

Grand Duchy - The dominion of the grand duke, who is higher ranking than the duke, but beneath the archduke. Usually a member of the royal family in line of succession.
Totalitarian - Totalitarianism (or totalitarian rule) is a concept used to describe political systems where a state regulates nearly every aspect of public and private life. Totalitarian regimes or movements maintain themselves in political power by means of an official all-embracing ideology and propaganda disseminated through the state-controlled mass media, a single party that controls the state, personality cults, central state-controlled economy, regulation and restriction of free discussion and criticism, the use of mass surveillance, and widespread use of terror tactics.
Trial by combat - Fight to the death, winner is innocent