D4 Forgotten Souls Drop Rates & Farming Routes (Season 9)

Forgotten Soul is essential for endgame optimization in Season 9: Sins of the Horadrim, particularly if you're aiming to fine-tune cooldowns, resource costs, or stats on gear. Read this D4 Forgotten Souls farm guide, we'll break down the drop rates, best methods, and routes to farm it.

What is Forgotten Soul in Diablo 4?

Forgotten Souls are a rare and essential crafting material in Diablo 4, primarily used for Masterworking gear—especially at higher tiers—and for upgrading legendary and unique D4 items. In Season 9: Sins of the Horadrim, they’re crucial for triple Masterworking, a powerful endgame enhancement system that requires massive quantities of these souls to fine-tune item affixes like cooldown reduction, resource cost, or damage rolls. Without Forgotten Souls, pushing your build to its peak potential becomes nearly impossible.

Best Ways to Farm Forgotten Souls in Diablo 4 Season 9 

1. Legion Events (Best Overall – Fast & Reliable)

Legion Events are currently the fastest and most consistent way to farm Forgotten Souls in Diablo 4 Season 9. These global events spawn every 25 minutes and can be completed in just 2–4 minutes, rewarding 200–250 Forgotten Souls on Torment IV difficulty. In addition to Souls, they also drop Veiled Crystals, Ancestral gear, and boss summon materials. By doing two Legion Events per hour, you can reliably farm up to 500 Forgotten Souls/hour. To maximize efficiency, track event timers using helltides and plan your rotations accordingly.

2. Material Reserves in Nightmare Dungeons

Forgotten Souls can also be obtained from Horadric Material Reserve chests hidden within Nightmare Dungeons. Each chest can drop 15 Forgotten Souls, but their locations are inconsistent and often tucked away in obscure corners of the dungeon. Because these chests are RNG-dependent and not guaranteed per run, this method is best used if you're already inside the dungeon for Glyph XP, Escalation farming, or other objectives. It’s not a primary method but a decent bonus while progressing other content.

3. Lair Boss Bug Farming (Fast Opticide + Bonus Souls)

One of the most efficient hybrid methods involves exploiting a known lair boss bug. Open a Nightmare Dungeon with a Strongroom affix, then teleport to different boss lairs (e.g., Grigoire, Lord Zur, Hangman’s Hall) to check if the Strongroom has spawned inside. If it has, you can instantly complete the Strongroom without running the dungeon, earning large amounts of Opticide and occasional Forgotten Souls. Lairs reset automatically, so you can keep rotating through bosses between Legion Events, making it a powerful way to stack both materials.

4. Undercity Tribute of Refinement

The Tribute of Refinement in the Undercity is a quick farming method primarily used to gather Opticide, though some Forgotten Souls may drop from elite mobs or chests during the run. It takes only 2–3 minutes to complete and yields around 2,000 Opticide per tribute. However, it requires Refinement Tribute currency, which can run out quickly. This method is most effective when done in coordination with friends to share Tribute runs, and is ideal for fast-moving builds.

5. Infernal Compass (Backup Method)

The Infernal Compass lets players enter Horde-style scenarios with 6, 8, or 10 waves, offering 3,500–4,000 Opticide and some Forgotten Souls per 10-wave run. However, each run has a fixed time duration (13 minutes for 10 waves) and the Forgotten Soul yield is lower compared to Legion Events. This method is best reserved for those also farming Ether, doing Challenge completions, or trying to spice up their grind with a wave-based encounter structure.

6. Nightmare Dungeon Escalation (with Strongroom Affix)

By stacking Nightmare Dungeon Escalation with the Strongroom affix, you can potentially activate modifiers like Opticide Mine, which significantly increases Opticide drops from monsters. These runs may also include Strongrooms inside the dungeon that yield additional Forgotten Souls. While not as time-efficient as Legion Events, this method is ideal for players looking to farm both Forgotten Souls and Opticide simultaneously—especially if they can quickly clear pre-rolled dungeons with favorable layouts.

D4 Season 9 Forgotten Soul Drop Rates

• Legion Events (Torment IV): Expect around 200–250 Forgotten Souls per event. Since they spawn every 25 minutes, this makes them the most consistent and rewarding source—roughly 500 Forgotten Souls per hour if you chain two events.

• Material Reserves (Nightmare Dungeons): Each Horadric chest may drop around 15 Forgotten Souls, but these are rare and randomly placed, making farming inefficient and inconsistent. Average drop rates are closer to 10–20 Souls per dungeon at best.

• Lair Boss Strongroom Farming: If a Strongroom spawns inside a lair boss dungeon, it can drop 20–40 Forgotten Souls, but it’s inconsistent and RNG-reliant. Still, it's a solid method when done between Legion timers.

• Nightmare Escalation with Strongroom + Mine Affix: Potentially yields 20–60 Forgotten Souls per dungeon if all modifiers align and monsters drop high quantities. This method is high-effort and requires pre-rolled setups for efficiency.

• Infernal Compass (10-wave): A full 10-wave run may drop 20–40 Forgotten Souls total from elites and chests, but the main reward is Opticide rather than Souls.

• Undercity Tribute of Refinement: Has a small chance to drop a handful of Forgotten Souls (~5–10), but this is unreliable and should not be used for direct Soul farming.

D4 Best Forgotten Soul Farming Routes (Season 9)

1. Start with Legion Event

Use helltides to track countdown

Complete Legion Event in 3 minutes → Get 250 Forgotten Souls

2. While Waiting (20–25 min)

Cycle through Lair Bosses for Strongroom Bug:

TP to:

Grigoire

Lord Zur

Urovar

Hangman’s Hall

Harbinger of Hatred

→ Look for purple flame aura (Strongroom present)

If you find one:

Instantly complete Strongroom

Collect Opticide + occasional Forgotten Souls

Restart cycle from first boss

3. Repeat:

Do Legion again

Resume Strongroom boss lair hopping

Optionally mix in:

Tribute of Refinement (if available)

Escalation dungeons (with affix synergy)

Whisper bounties for Grim Favors (Tree of Whispers bonuses)