While many fans have been disappointed that they'll never see the end of Guillermo del Toro's Hellboy trilogy, they've been bolstered by the idea that the planned reboot is going to be a much darker story than the previous iteration. The new Hellboy is being written from the start to be an R-rated movie. According to Hellboy's creator Mike Mignola, the idea behind making an R-rated Hellboy isn't specifically to be able to do anything particularly violent, but simply to give the creators the freedom to do what they want and not have to worry about hitting limits. They are making a horror movie, after all. According to Mignola...
It'll lean in the horror direction, more so than the fantasy direction del Toro was doing. When Neil came on, we decided to go for an R rating, so he doesn't have his hands tied, and so he can go as dark and as tough as he wants to go. I was a fan of his, and when he came onboard, I thought it was terrific: now it's really going to be an action-horror film. It's not that we want to wallow in blood, but when you do a PG-13 rating, you bang your head into rules about how intense certain things can be. I think it helps that Deadpool and Logan were R-rated, and what I've been telling people is that the tone of it will be much more the Logan approach: lean, dark, tough, and not something that stops to show limbs flying through the air.
As Mike Mignola tells The Verge, neither Deadpool nor Logan, particularly wallowed in their violence. Instead, they simply didn't shy away from showing blood and using whatever language they wanted to use. The issue, according to Mike Mignola, is one of intensity and while that can be hard to define, most would agree that Logan was a significantly more intense movie than its predecessors. Mignola thinks the filmmakers will be doing something similar with the new Hellboy.
The R-rating certainly does give filmmakers some amount of freedom as they don't really have to think about the rating when putting the story together. Nobody has to consider whether or not a scene will be too intense or violent for a PG-13 rating, an idea which can be difficult to judge as it is. Considering that the new Hellboy is looking to be more of an action-horror movie, as opposed to the action-fantasy of the previous series, we'd expect that the movie is going to have its share of scary and violent moments, and doing that within the confines of a PG-13 story can be quite difficult to pull off well. Film is a visual medium, and if you want your horror movie to be scary, often times you need to actually show things that are truly terrifying. We'll see what we get when the new Hellboy makes its way to screens.