Diablo 4 Season 9: Herodric Spellcraft and Jewels

Season 9 of Diablo 4 doesn't just introduce a new seasonal gimmick-it adds permanent gameplay systems that redefine endgame dungeon crawling. With the debut of Herodric Strong Rooms and Escalating Nightmare Dungeons, Blizzard has blended a compelling mix of monster-slaying chaos and thoughtful resource farming. And if you're chasing peak seasonal power, the name of the game is simple: Herodric Spellcraft and Jewels.

In this guide, we'll break down how to access and efficiently farm these new features, what you need to know about Herodric Attunement, how to handle the Astaroth boss fight, and why Escalating Nightmares might just be the most efficient grind Blizzard has ever added.

What Are Herodric Strong Rooms?

Herodric Strong Rooms are instanced, monster-filled mini-challenges that spawn within Nightmare Dungeons, including those inside Escalating Nightmares. You'll know you've found one when your map lights up and your screen begins highlighting the route toward a strange pillar.

Once you interact with the Strong Room pillar:

 Waves of monsters spawn. Clear them.

 A portal opens, leading to a new chamber with additional waves and pillar choices.

 Pick your pillar modifiers-some increase mob density, others give you a Herodric backpack item that boosts Attunement gain (as long as you don't evade or drink a potion).

 Afterward, you enter the final timed room: 100 seconds to fill your Attunement bar by slaying enemies and activating more pillars or Shrines of Sacrifice, which spawn elite packs.

Fill the bar, and you'll face a boss fight. Defeat it, and the reward chest that spawns will drop:

 Herodric Spellcraft materials

 Catalysts and Infusions

 Rare and Legendary Arcana

 Recipes for crafting Herodric Jewels (Torment I and higher only)

Pro tip: As of the latest patch, Arcana drop rates have been improved but still aren't guaranteed. Maxing out your Attunement bar increases your odds dramatically.

What Is Herodric Attunement?

Herodric Attunement is a seasonal resource bar that fills up during Strong Room encounters. Killing enemies, triggering elite waves, and interacting with special mechanics all contribute to Attunement.

Here's how to maximize your gains:

 Choose pillars that spawn ambushes or offer Attunement boosts.

 Use your Herodric backpack item if your build allows.

 Activate Shrines of Sacrifice while a pillar is active to double up efficiency.

Clear all in-room pillars to reset them and go again if you haven't capped your bar.

At full Attunement, you'll face a stronger boss and earn better loot-including the Arcana and recipes needed to craft your Herodric Jewels.

Escalating Nightmares: Dungeon Gauntlets That Matter

Introduced in Season 9 but sticking around permanently, Escalating Nightmare Dungeons are multi-part gauntlets where each dungeon in the chain adds more difficulty and affixes.

 Dungeon 1: Standard Nightmare run

 Dungeon 2: All affixes from Dungeon 1 + new ones

 Dungeon 3: Everything from 1 & 2 + more new ones

Each dungeon in the chain can contain a Herodric Strong Room, meaning a full escalation could grant up to three Strong Rooms per run. Complete all three, and you unlock a final boss fight against Astaroth.

Escalating Nightmare Efficiency Tip: These runs are the best way to farm Strong Room rewards, Herodric crafting currency, and sigils. You get loot from every dungeon and a big payday from the final boss.

The Astaroth Fight: What You Need to Know

Astaroth isn't too complex, but his multi-phase mechanics can be lethal if ignored:

 He starts mounted on a hellhound. Deplete his HP, and he dismounts.

 The dog teleports to the center and begins healing.

 As it heals, a circle of deadly liquid expands outward. Stay out, or die fast.

 Once the bar is full, the liquid disappears and the dog resurrects as a boss.

 You can kill the dog again, but the phase will repeat.

Strategy: Either focus down Astaroth to end the fight early or manage the dog phase carefully. Once Astaroth dies, the fight ends regardless of the dog's state.

Farming Spellcraft and Jewels: What Drops Where?

Catalysts and Infusions

 Drop naturally during Strong Rooms.

 Guaranteed drops after major seasonal quest milestones.

 Color-coded like item rarities: Blue (Magic), Yellow (Rare), Orange (Legendary).

Tip: Many players miss blue/yellow drops thinking they're trash gear. 

They're not!

Arcana

 Random but improved drop rates post-patch.

 Only Rare and Legendary Arcana unlock after you claim reputation rewards from the Herodric Focus in Serarr.

 Don't ignore your blue and yellow loot until you double-check.

Herodric Jewel Recipes

 Start dropping in Torment I and up.

 Guaranteed "Spark of Creation" jewel from reputation track.

 Other recipes are RNG but can drop two at once from a single chestif Attunement is maxed.

Seasonal Crafting Currency

 Main source: Strong Rooms, Escalating Nightmares, and Astaroth.

 Astaroth drops 1,000+ currency per run, even on Torment I.

Gem Fragments

 Farmed through Infernal Hordes or Herodric Gem Reserve affix in Nightmare Dungeons.

 This affix spawns chests throughout the dungeon filled with fragments.

 Just 2-3 escalations with this affix can net you enough for a full jewel craft.

Sigils: How to Farm Escalating Nightmare Access

Want more Escalating Nightmares? You'll need the sigils.

 Drop from Strong Room chests, especially with max Attunement.

 RNG based, but higher tiers = better odds.

 Escalating Nightmares can contain Strong Rooms that drop these same sigils-creating a self-sustaining loop.

Final Thoughts on Season 9's Systems

Season 9 introduces a blend of routine structure and meaningful reward. While the Herodric Spellcraft and Jewel system may not reinvent the power curve, it absolutely enhances builds in flexible and impactful ways.

 Infusions offer build-specific utility like elemental damage boosts or suppressor counterplay.

 Jewels are easier to craft than in previous seasons.

 Escalating Nightmares offer progression, efficiency, and variety-without tedious downtime.

With most of this content becoming permanent (Strong Rooms, Nightmare changes, and Escalating Dungeons), Diablo 4's endgame just got significantly more robust. Buy Diablo 4 Items and Diablo 4 Gold from MMOexp shop, quickly enhance your gaming experience.

Whether you're playing solo or grouped, if you're not farming Strong Rooms and Escalations, you're missing out on the core of seasonal progression in Diablo 4.

MMOexp Diablo 4 Team