The new film is out soon so if you want a modicum of preparation, read this.
Everything You Need To Know About Judge Dredd
Born (well, cloned actually) in the year 2066, Joe Dredd grew up to become a street judge of Mega-City One, a massive urban metroplex encompassing the eastern coast of North America. By the time Dredd is an adult, most of the continent is a radioactive hellhole called The Cursed Earth. (Here are some wonderfully depressing maps of Dredd's world.) Because of the Mega-City One's sprawl, population, and science gone wild, the street judges — who must eschew all relationships (including sexual ones) in the name of the law — are granted the all-in-one legal powers of judge, jury, and executioner. (For example, one of the prisons in Mega-City One is just a giant ladder-less pillar surrounded by elevated highways.)
And nobody epitomizes the Judges' lifestyle quite like Dredd. For example, he (almost) never takes off his helmet, will arrest you for the slightest infraction, and barely sleeps. (Explains Wagner, "He usually only gets ten minutes in the sleep machine, hardly time to disrobe.") It's also worthy mentioning that Judge Dredd ages in real time — since debuting in the 1970s, he's now a spry seventy-something.
. . .
Dredd's harshness is leavened by crimes that are often over-the-top ludicrous, supernatural, or a satirical commentary on contemporary society. Dredd (the movie) looks rather grim and grimy, but this tone isn't indicative of the character's historical tenor (i.e. Dredd's rogues gallery includes the morbidly obese).
Joe Dredd is a monomaniacal guy, but he's not a loner. He's frequently joined by fellow Judges like Hershey and Anderson to do battle with such foes as the cybernetic Angel Gang and the demonic Dark Judges.
. . .