Eventually, Diablo 4 will reach a stage where instead of grinding levels, you will be grinding gear. Unique items give your class unique bonuses and are essential to ascending toward the RPG's level 100 cap.

Instead of blindly roaming dungeons and gambling with Murmuring Obols for gear, Diablo 4's monster family system (a truly unfortunate name) allows you to actually target specific item types. For example, a necromancer in desperate need of a scythe can search for drowned enemies, or if he needs a unique helmet to complete his build, he can focus on fighting cultists.

Once you finish the campaign and start walking the long road beyond level 50, you will see why Unique items can be a big help in the difficult World Tier. Normal enemies and bosses are highly aggressive, and you need to have some synergy between your equipment and skill tree in order to survive. My Necromancer Bone Spear build didn't feel quite right until I got a Deathless Visage helmet to increase my AoE damage.

The details of the monster family are still vague, and it is unclear if the increased drop rate will apply to unique items. But even if not, this system could be useful for those who have not yet reached level 100. Rare and Legendary items have powerful stats that can be upgraded or converted to certain Legendaries with passive bonuses from the "Aspects of Power". This is because any mechanism that helps take advantage of the unforgivable nature of RNG drops is worth trying.

Here are the items that each monster family drops:

If you are not sure what specific items you need, just look for which gear slot in the character panel has the lowest item level and target the monster family that drops it. Elite enemies are more likely to drop items, so farm monsters in dungeons or at open-world events like Helltide or Stronghold.

I'm sure someone will do the math and clarify whether the drop rate of monster families is important enough to choose farming monster families over farming regular enemies; since most of Diablo 4's systems seem to be built around the endgame, this is more than it seems. I would not be surprised if it is useful. Also, Blizzard has a major balance patch coming, which may include changes that emphasize targeted item farming. Otherwise, everyone will be refreshing YouTube and Reddit to find the latest broken dungeon farm location.