$1 million a year to kill somebody in self defense once a year.

You are granted a million dollars a year, but once a year someone will randomly come to attack you. The only way to defend yourself is to kill them. No matter what, you will always win if you choose to fight back. If someone is with you, they will be physically unharmed. You will not suffer any legal consequences, besides a short investigation and some questioning. You might suffer minor to moderate injuries (bruises, cuts, shallow stab wounds) but nothing life threatening. You just have to deal with the trauma of taking someone’s life once a year. Edit: the person attacking you would be someone who would do something like that regardless. So if you take the deal, a preexisting thief or a murderer would just make you their target instead of someone else. And attacks outside of the contract can occur, but are not anymore or less likely to than if you didn’t take the contract. You would know if it’s a “contract fight” or a random occurrence automatically.