We’re asked to accept that, nine years in the future, America is taken over by a gratuitous theocratic system that has successfully eliminated the crime rate by encouraging the Purge, a 12-hour window that opens one day out of the year for the “haves” to go out and slaughter the have-nots with impunity. (Politicians, of course, are off-limits.) Apparently, the system is working out: The unemployment rate is down to 1 percent, and crime is virtually non-existent. So here we end up with a masked posse of bored rich kids terrorizing a bunkered estate in a gated community during the Purge. The movie exists only to let the intruders crash the gates so people can go about plodding through dark hallways, stalking and killing other people until the end credits. Cinemark 14 and Feather River Cinemas. Rated R.