Gem Corruption and Leveling Profits
This calculator shows which gems are actually worth corrupting. For every gem on poe.ninja, it runs the expected value math across all four Vaal outcomes and tells you the average profit per attempt.
Launch Gem Profit →How It Works
- Prices for every gem — uncorrupted base and all corruption results — come from poe.ninja.
- For each gem, expected value is calculated across the four Vaal outcomes (25% each). Profit = expected value minus the base gem cost. Exceptional gems (Enlighten, Empower, Enhance) are tracked separately since their value is all about levels.
- The corruption matrix breaks down each outcome's value so you can see whether you're banking on the 21 hit, the Vaal version, or something else.
Example: Corrupting a 20/20 Awakened Spell Cascade
Suppose an uncorrupted 20/20 Awakened Spell Cascade costs 5 divine orbs, and the four Vaal outcomes price out at: Level 21 → 18 div, +23% quality → 7 div, Vaal version → not applicable (no Vaal Awakened gems), brick (-1 level or -1 to -10% quality) → 0.8 div on average.
Expected value = (0.25 × 18) + (0.25 × 7) + (0.25 × 5) + (0.25 × 0.8) = 4.5 + 1.75 + 1.25 + 0.2 = 7.7 div. Subtract the 5 div base cost and the profit per attempt is +2.7 div. Over 20 corruptions you would spend 100 div and expect 154 div back.
The variance is brutal on a sample of one. One unlucky run of four -1 level bricks in a row costs you 20 div against expectation. Only corrupt in bulk, or only corrupt gems you can afford to lose.
Tips
- High expected value does not mean guaranteed profit. You need to corrupt many gems for the statistics to work in your favor — a single -1 level or -quality roll can wipe out the gains from several successful corruptions.
- Gems where the Vaal version is extremely valuable (like Vaal Grace or Vaal Haste) tend to have the best expected returns, since one outcome alone justifies the corruption cost.
- Sort by profit to find gems where corruption is most profitable on average, then check if you can actually buy the uncorrupted version at the listed price.
- Quality matters — a 20/20 gem (level 20, 20% quality) is the standard starting point. Outcome probabilities stay at 25% each regardless of base quality, but the ending values shift (a 20/20 that gets +10% quality caps at 23%).
Common Mistakes
- Corrupting a single gem and treating the result as the expected outcome. Expected value is a long-run average — a single attempt has a 50% chance of a net loss on most gems.
- Ignoring the bid-ask spread. The profit number uses listed prices, but you usually buy the base at the ask and sell the result at the bid. On thin markets the spread can eat most of the edge.
- Corrupting gems that are rarely traded. A gem with only two listings at the "top outcome" price means your corrupted copy may sit unsold for days.
- Forgetting that exceptional gems (Enlighten/Empower/Enhance) max at level 3 uncorrupted, and +1 corruption takes them to level 4 — the big payday. Starting from level 2 is almost never profitable.
Frequently Asked Questions
- What is a gem brick?
- A brick is when corruption rolls -1 level or drops your quality — the gem loses value and, since it's now corrupted, you can't fix it with GCPs or leveling.
- How are exceptional gems different?
- Enlighten, Empower, and Enhance gain most of their value from levels rather than the skill itself. A level 4 Enlighten is worth vastly more than level 3. The corruption math still applies but the level +1 outcome is usually where all the profit sits.
- Why does a gem show high profit but I cannot find it for sale?
- Some gems are rarely listed at the base price poe.ninja reports. The price might be based on a single listing or stale data. Check the actual trade site before committing to a corruption strategy.
- Does this account for the cost of Vaal Orbs?
- The profit column reflects gem price differences only. Vaal Orbs cost roughly 1 chaos, which is negligible for most gem corruptions but worth noting for cheaper gems.
- Can I corrupt a level 21 gem further?
- No. Vaal Orbs only work on uncorrupted gems. Once a gem is corrupted — whether from a successful +1 or a brick outcome — it cannot be corrupted again, levelled past its current level via experience, or have its quality changed with Gemcutter's Prisms.
- Does quality above 20% help before corruption?
- Slightly. Higher starting quality means the quality outcome lands closer to the 23% cap. Worth a small premium on expensive gems, but not a game-changer.
- Are Awakened gems handled the same way?
- Mostly. They cap at level 5, so +1 corruption hits level 6 (the money outcome). No Vaal version exists for Awakened gems, so that slot rolls no-change instead — fewer bricks, but one less upside.
- What do the numbers mean when profit is negative?
- Negative profit means the expected value of the corrupted gem is lower than the cost of the uncorrupted base. This is typical for most gems — only a minority of gems have Vaal versions or level +1 outcomes valuable enough to justify the risk. Filter for positive profit and sort descending to see the few that are worth corrupting.