Mutation
Dirty
Updated:
Lowers an item's sell value below its base price — typically applied automatically to items rescued from filthy lockers.
- Value Multiplier
- 0.8x
- Visual Style
- Brown muddy gradient overlay
- Obtainable
- yes
- Source
- ✅ verified
Overview
Dirty is the 0.8x mutation in Storage Hunters: Open World — a negative entry in the 24-mutation roster. Dirty is the ONLY confirmed negative multiplier in the entire mutation set at 0.8x — it lowers an item's sell price below its base.
Brown muddy gradient overlay — the visual is a warning, not a flex. Applied to a Scrap Dominus ($565 base, the canonical mutation-stacking example from the mutation-strategy guide), a single Dirty roll lands the item at roughly $452 pre-stack.
In Depth
Dirty applies a 0.8x multiplier to an item's sell price. The mutation is identified visually by its brown muddy gradient overlay, and per the entity record it is obtainable through normal play (`obtain: yes`).
Like every confirmed mutation, Dirty contributes additively when stacked with other mutations on the same item. The mutation-strategy guide states the rule plainly: "When an item rolls multiple mutations, the multipliers ADD — they do not multiply." A Silver (2x) plus Gold (4x) item sells for 6x base, not 8x. Read Dirty's 0.8x the same way — it contributes 0.8x to whatever the total stack multiplier ends up being, not as a standalone "0.8x on top of everything else" effect.
Concretely: a Scrap Dominus ($565 base) with a single Dirty roll lands at roughly $452. The same Scrap Dominus with the same Dirty plus a Void (35x) lands at ($565 × (0.8 + 35 − 1)) = $19,662 — the additive math is what makes high-base items the right place to chase Dirty stacks, not low-base junk loot.
Mechanics
- Multiplier: 0.8x (numeric 0.8), applied at sell time.
- Tier: negative — the only mutation in this tier among the 24-mutation roster.
- Stacking rule: additive (not multiplicative). Multiple mutations on the same item combine into a single summed multiplier, per the mutation-strategy guide.
- Visual identifier: Brown muddy gradient overlay.
- Area-agnostic: the mutation system applies to every item regardless of which area's auction it came from — Junk Yard, Back Alley, Farmyard, and Shipyard all roll under the same rules.
- Source confidence: multiplier value verified against existing entity data; drop rates and per-area odds explicitly NOT documented per the mutation-strategy guide.
Pros & Cons
Pros
- 0.8x contribution to any item it rolls on — meaningful payout when applied to high-base loot.
- Additive stacking means this mutation always contributes its full value to a combined stack — no diminishing returns.
- Light multiplier — still positive, and contributes additively to stacks even if it does not pay off massively on its own.
- Area-agnostic — can roll on items from any of the four areas, so chasing it does not lock you into a specific progression stage.
Cons
- Stand-alone value is small — a single roll without other mutations on the same item produces only a modest premium.
- Drop rates and per-area odds are not publicly documented — strategic planning relies on volume play rather than targeted chasing.
- This mutation lowers sell value rather than raising it — selling a Dirty item raw destroys margin.
- Combining mutations requires repeated favourable rolls on the same item, which the public wiki does not document as a controllable process.
Quick Reference
| Multiplier | 0.8x |
|---|---|
| Numeric Value (for stacking) | 0.8 |
| Tier | negative |
| Visual Identifier | Brown muddy gradient overlay |
| Obtainable | Yes (drop conditions not exhaustively documented) |
| Stacking Rule | Additive — combines with other mutations as a sum, not a product (mutation-strategy guide) |
| Source Confidence | Multiplier verified against existing entity data + mutation-strategy guide |
How To Use
- Use the Mutation Stacker calculator (/tools/mutation-stacker) to model Dirty's 0.8x contribution against any item base price before chasing the roll on auction.
- Stack Dirty with other mutations to maximise return — remember the additive rule: a 0.8x plus another 5x mutation lands at 5.8x total, not 4x.
- Target Dirty rolls on the highest-base items you can afford to bid on — Shipyard machinery (Industrial Robot Arm, Hydraulic Press) and Exclusive accessories (Gangster Dominus class) pay back the multiplier most clearly.
- Do not sell Dirty items raw — even one additional positive mutation on the same item cancels the negative multiplier, per the mutation-strategy guide's first stacking rule.
- Track which auctions and areas tend to produce mutated items in your sessions — public sources do not document drop rates, so the only meaningful data is your own observation.
Patch History
- Patch-level history for this mutation is not publicly documented on the Storage Hunters Wiki at the time of writing. Refer to the official Roblox game page for the latest in-game update notes.