Less than 24 hours after the Early Access release began, the first hotfix for Diablo 4 was released. The update features minor nerfs to the Sorcerer and Rogue classes and increases to the health of monsters with higher World Tiers, making life more difficult for everyone.

World Tiers in Diablo 4 are essentially difficulty levels. However, this system is a bit more limited than many other games: it is basically "easy" and "normal" levels. World Tier 3 (Nightmare) and World Tier 4 (Torment) are not available until the campaign is completed.

Moving to a higher World Tier increases both the challenge and the reward: for example, at World Tier 3, the XP bonus is 100%, but non-physical resistance is reduced by 20% and enemy difficulty increases. However, Blizzard is currently boosting their health a bit, which apparently is not enough.

Rogues have been adjusted very slightly in the hotfix. There is now a short delay in marking enemies after the unlimited energy of the Inner Sight runs out, and the Sorcerer's Flame Shield is now on full cooldown when placed in the enchantment slot, so you have to wait a bit before you can use it.

It has not yet been revealed which World Tiers will have Healthier monsters, but the general feeling on Reddit is that W3 and W4 will. I have contacted Blizzard for clarification, and frankly I think Reddit is correct.

The Diablo 4 hotfix brings the game to version 1.0.2 and is a server-side patch. The full patch notes can be found below.

Sorcerer - Class Specialization

Flame Shield Enchantment

Rogue - Class Specialization

Inner Sight

ItemsShout Skill Cooldown Reduction

Miscellaneous [23]