The look at how monsters and dungeons work is both familiar and different in what was shown of Diablo IV’s gameplay and design. Monsters still come in three major types: common, Elite, and Boss (it’s unclear whether there are still the two tiers of blue and yellow elites, however).
Common enemies are your bog-standard cannon fodder as usual, but it’s interesting to note that each of the various types seems to have a distinct role in their “family” this time around. Skeleton enemies act and have abilities completely separate from the other showcased family: the Fallen. Where skeletons are distinguished mainly based on their weapons (shield skeletons eat hits and stun players, two-handed weapon skeletons deal relatively huge damage, and archers shoot) Fallen are varied based on their powers, with Grunts mobbing the player and constricting their movements, Lunatics self-destructing, and Shamans providing magical support with fireballs and resurrection magic.
I look forward to seeing what new families bring to the table.
This focus on unique abilities for even basic enemy types opens up a new avenue for affixes in Elites. While more standard affixes are returning for certain (Mortar and Frozen have already been confirmed. This leads me to believe we can all continue to cower in fear of Arcane enemies as well), there is an entirely new type of affix now: Enhancing affixes.
Enhancing affixes enhance the Elite’s basic abilities by adding some special quality to it. The one showcased is Multishot, which has wildly variable effects based on what kind of monster is affected by it. The Skeleton Ballista (a huge mass of bone who fires at you offscreen with a ballista) is affected by Multishot by firing three ballista bolts at once. This is completely different from a Multishot Shaman, who instead resurrects multiple enemies with each cast of its rez ability.
These new enemy types and affixes should add a lot to the game, and remind me of fighting enemies like the Morlu Incinerator in Diablo 3, which effectively already has the Mortar affix but gets a bunch of other free one son top.
The details about bosses were scarce, save that they are returning, some are world bosses (like Ashava, an enormous scaly demon who uses huge sweeping attacks with the bone blades on its elbow), and it appears there is a focus on their abilities being more varied this time around. The example given was of the Tomb Lord, a massive skeletal necromancer who uses bone in many ways, including raising (and resurrecting) minions, creating walls of bone to constrict your progress, and trapping and blinding the player.
So far, it all looks very promising.