To push the crime rate below one percent for the rest of the year, the New Founding Fathers of America test a sociological theory that vents aggression for one night in one isolated community. But when the violence of oppressors meets the rage of the others, the contagion will explode from the trial-city borders and spread across the nation.
This movie contains 45 potentially triggering events.
I'm not sure, as I didn't pay too close attention, but someone has very bad teeth (possibly from meth/crack, as the guy is completely off his rockers and lives in a tough urban environment).
The comment mentioning a bathtub scene is referring to another movie or a series; this is the movie "The First Purge" (2018). There's no shower scene either.
There is a lot of blood throughout the film as people are stabbed, shot, and otherwise attacked. but it doesn't feel excessive and the camera doesn't linger on it.