Meaning whomever did you wrong or want dead you can legally kill them for the next twelve hours. I was just in "AHH"! Just imagine you can go out and kill homeless people your ex-boss or ex-wife whom ever you want and whom ever wants to kill you also. Crazy right and Ethan Hawk plays a great roll in this also, who had to defend his family till the very end from not only his daughters boyfriend who tried to kill him, but from savage killers who wanted to kill a homeless man that his family took in because of his caring son.
The wicked twist in this movie was his neighbors not only saved his family's life from the savage killers but wanted to kill them also just off of animosity and jealousy. Witch means you cant trust anybody who smiles in your face not even your dearest neighbor, when it comes to the day of The Purge. Cool story line, plot and gore if that's what you like! It left chills in the air.