Unique Class Mechanics in Diablo IV - Necromancer, Rogue, Sorcerer

wowhead.com:

While every class and build in Diablo IV has something that makes them unique — be it flashy spells, shapeshifting abilities, or the ability to specialize in weapons the more you use them — there's something that further separates each class from the others. Diablo IV introduces Class Mechanics to the franchise, allowing players to enhance their characters even more than by just putting points into a skill tree. These thematic abilities lie at the core of what makes a class unique. The element wielding Sorcerers, for example, can take a spell and fine-tune it into something even more powerful with their Enchantment mechanic, fitting right in with the thought of a scholarly, wise mage. Necromancer Class OverviewRogue Class OverviewSorcerer Class Overview While some Class Mechanics aren't available during the Open Beta Weekend, we haven't forgotten about them. Barbarians and Druids sadly cannot take full advantage of their Class Mechanics, since the quests they need to unlock the experience begin in different zones. That being said, we've gathered information on the three that are — Necromancer, Rogue, and Sorcerer — and what little we know about Druid and Barbarian below!

With the Necromancer's focus on summoning, it makes sense that the Book of the Dead Class Mechanic is all about customization. What type of magic should your Skeletal Mages use? How should your rank — and — file Skeletons approach combat? What are your golems made of? All important questions — but the most important of all is yet to come. Should you sacrifice your summons entirely for powerful passive bonuses? The Book of the Dead lets you choose all of the above! Necromancer Book of the Dead