It was actually quite surprising to find out how simple and straightforward this movie was being. It pretty much jumps right into the action and doesn't ever really take the time to setup its world and characters. It's really a movie without any distractions and moves right toward its goal, without making things ever deep or complicated. It might sound as a complain but it really isn't. After all, as the movie progresses we do learn about its characters and get to understand the futuristic world it is taking place in. So it really doesn't ever feel like the movie is wasting time with anything and every time you think the movie is starting to get deeper, more serious or complicated, it goes right back to its action.
And since this movie is taking place in a futuristic world, it has plenty of original elements in it. This also really goes for its action. It allows itself to become really creative with its weaponry and action, which means that the movie often manages to surprise you with stuff and the movie never starts to repeat itself, even though its mostly taking place at one location, with also just an handful of different characters involved.
It's foremost the action that makes this movie a worthwhile experience and its handled and shot very well by both its cast and crew. The movie has a good look to it and doesn't ever try to blow you away with one particular special effect shot or action sequences but rather tries to impress you with its whole end product.
It of course is also being its main character that lets the movie work out. He's a tough and mysterious person, who walks the fine line of what's considered to be good and bad. Sure, Karl Urban does a good job playing the character but in all honestly, it really didn't mattered who would had played him. After all, you most certainly won't be able to recognize Urban in this movie, mostly due to the reason that he never takes of his helmet, which is actually being a good and effective thing for the movie and its main character in general.
Of course when you start nitpicking you could find plenty of flaws to this movie and story but some movies are just made to simply enjoy, without letting you think too much or too long about anything that's happening in it. It might be try that this at the same time makes "Dredd 3D" a somewhat forgettable movie but when you watch you'll simply have a great time, regardless of that!