My heir is unfit for the throne. How can I make him aware of this fact?
There are no direct covert actions that will let you kill your heir. However, do not lose hope, for there is still a chance at murder.
- There are a few random events that can either: a) let you choose an option that kills your heir or, b) simply kills your heir (the hunting accident event, for example)
A much more direct approach:
- You can assign your heir to become a general in the Military tab. Then, put him in command of a thousand brave troops and send him to war against an overwhelming enemy. Repeat until he is dead.
With the Rights of Man DLC enabled:
- A country may disinherit an heir if so is wished, at a cost of 50 prestige. After this action is done the country won't have any legal heir and will be at risk of falling under a Personal Union, just like any other country without a legal heir (It is not possible to "return" to the disinherited heir).
If you don't mind using cheats, there's a console command: kill_heir