In today's Developer Livestream, Blizzard explained how the Armor stat currently works in Season 3, as well as the changes developers are making for Season 4. The thinking behind this change is to balance out how players are experiencing defensives in top-end play and reduce the mystery involved in one-shot deaths players experience.
Diablo 4 Season 4 Developer Livestream Summary
Oftentimes, the key to end-game defense meant stacking Damage Reduction across various slots. To that end, physical resistance was capped at 85%, and as noted below, players were unclear on what was required to cap out their defensives and prevent one-shot deaths.
In Season 4, Armor will cap out when fighting Level 100 monsters, so in other words, once players reach 9,230 Armor (which will likely happen in World Tier 4) they are finished with this part of gearing. Leveling progression, on the other hand, will require players needing escalating amounts of Armor as monster level increases.
What do you think of the armor rework in Season 4? Let us know in the comments below!