[Update #2]: Diablo 4 devs have detailed their plans for player skills, items and unique legendaries.
[Update]: The classic Diablo 2 is now celebrating its 20th anniversary!
While Diablo 4 is still a mere speck on the horizon, Blizzard has slowly but surely been revealing more details about it, as well as what the team is trying to achieve in regards to both gameplay and story. Last time around they talked about the UI, monster design and control schemes, while the latest update is all about the storytelling, problems and benefits of open world gameplay, as well as multiplayer.
"One of the main new features we are bringing to the Diablo series is the open world of Sanctuary," reads the lengthy update. "So, while you can concentrate on the story campaign and work through that, we have a variety of open world systems and pieces of content that you are also discovering along the way. If you want to take a break from the main campaign and go exploring, crafting, or PvPing, you are free to do so."
"During the playtest, we saw this variability in action quite a bit. On an average playthrough, team members took several hours to complete the campaign content for the region, but those who focused only on the story finished the arc in less than half the average time (and were, of course, able to do side content after that). We think the ability to approach the game with a different mix of story and side content tailored to your own appetite will make playing (and re-playing) the campaign more enjoyable than it has been in previous ARPGs."
Heat map showing how players explored one of the open world zones
Naturally, when you have a large open world to explore, transportation quickly becomes a problem. In order to sort this out, as well as give players an additional degree of customization, Diablo 4 is looking to add mounts with their very own itemization.
"We really liked how the open world interacts with mounts—you could get to your objectives more quickly without trivializing travel or combat," continues the blog post. "Itemization for mounts also opened up a new axis of progression."
"One of my favorite things about mounts was customizing it by attaching a trophy to the saddle to signal to other players that I had completed an obscure challenge in the zone. Of course, there is more work to be done on mounts. For example, on navigation and tuning, it is currently too easy to get stuck on stray pieces of collision or to get dismounted by a random enemy projectile. These are all things that are just going to get better the more we play and tune the feature."
All of this is just a small tidbit of what the Diablo 4 devs have revealed so far, so if you're interested in learning more, I'd highly recommend you read through the newest developer update. Enjoy!