Tradeskill Success Rates
Every tradeskill combine in EverQuest has a calculated success rate based on two things: your current skill and the recipe's trivial level. Understanding the math lets you predict your odds and plan your leveling path efficiently.
The Formula
The game converts a recipe's trivial level into an internal difficulty value, then compares that against your skill. The simplified version that players have reverse-engineered:
When trivial is 68 or higher:
Success% = Skill - (0.75 × Trivial) + 51.5
When trivial is below 68:
Success% = Skill - Trivial + 66
The result is then clamped between a floor of 5% and a ceiling of 95%. You always have at least a 5% chance to fail, and you never have better than 95% odds to succeed.
How Difficulty Works Internally
Under the hood, the game uses a difficulty value rather than the trivial directly:
Success% = Skill + 50 - Difficulty
The trivial-to-difficulty conversion:
| Trivial Range | Conversion |
|---|---|
| Difficulty ≤ 50 | Trivial = Difficulty + 16 |
| Difficulty > 50 | Trivial = (4/3 × Difficulty) + 2 |
You don't need to memorize this — the simplified formulas above account for the conversion already. But it explains why the formula changes at trivial 68: that's the breakpoint where the difficulty mapping shifts.
Quick Reference
Here's what the formula looks like in practice at a few common skill/trivial combinations:
| Skill | Trivial | Success Rate |
|---|---|---|
| 100 | 100 | ~77% |
| 100 | 150 | ~39% |
| 200 | 200 | ~77% |
| 200 | 250 | ~64% |
| 300 | 300 | ~77% |
| 300 | 350 | ~64% |
| 300 | 400 | ~52% |
Key Takeaways
The floor matters. Even with a skill of 1 attempting a trivial 400 recipe, you still have a 5% chance to succeed. This is how players occasionally pull off combines way above their skill — it's just slow and expensive.
The ceiling matters too. At 95% max success, you will still fail roughly 1 in 20 combines no matter how far your skill exceeds the trivial. For expensive recipes, budget for failures.
Skill modifiers affect success but not trivial checks. Items that grant +% to a tradeskill (Geerlok tools, trophies) increase your effective skill for the success calculation, which directly improves your odds. See the Geerlok and Modifiers guide for details.
Success vs. Skill-Ups
Success rate and skill-up chance are separate rolls. You can gain a skill point on either a successful or failed combine, as long as the recipe is not yet trivial for you. The success rate formula only determines whether you get the finished product or lose your components.