Earlier this year, DREDD producer Adi Shankar said there has been talks of a sequel, however he also said there's no script yet. While speaking at the Chicago Comic-Con, Karl Urban revealed there's a good chance DREDD 2 will happen, but it might be a prequel (of sorts) instead of a sequel.
Why yes, there is a definite possibility. But, it is more likely that we will do the origins story with Dredd trekking through the cursed earth to find the first Chief Judge Fargo.
Notice how Karl Urban says "the," and not "an" origins story? That's because he's probably talking about the Origins storyline from the comics, which uses flashbacks to explore Chief Judge Fargo's early life, including how he helped create the Judges. Last year Urban said he would be interested in doing an origins story to see "how that world got the way it got" in DREDD. Sounds to me he just might get his wish, if another movie does get made, of course.
I know people who aren't DREDD fans are a little sick of others talking about a possible sequel, however there are many who think Karl Urban definitely deserves another chance to play the character. But will it happen? I guess we're going to have to wait and see.