You will only have two locks and one perma-lock to use to lock your windows. Make it until six in the morning when the police arrive and you finally survive.
Opening windows helps you hear the killer better, but, you run the risk of letting him find you. The more you look at him, the faster and angrier he gets.
The same thing will never happen twice in each game you play. Be careful of the stranger and survive into the morning.
How to Find the Permalock in Stranger
The perma-lock is not something you have to level up to achieve, but instead, you have to find things first.
In each game, before the perma-lock is available for you to use, you must find the two regular locks. The stranger will travel around your house, when you see or hear him, place a lock on that window.
Be careful with your perma-lock, because once you place it on a window, you cannot pick it back up. Utilize your other two locks on each of the windows.
So far it seems the perma-lock can spawn randomly on each map. So make sure to look around. It can appear on the ground, and a popular location on the first map is next to the television on the ground.