Task Bar Hero DB

Synthesis Odds & Fusion Calculator

Fuse 9 same-grade items into one of a higher grade. Below Immortal every fuse is a guaranteed grade-up — Immortal is the first grade where a fuse can fail and stay put. Here are the exact odds, plus how many materials each climb really costs. Synthesis runs in the Cube — see The Cube guide for the leveling roadmap.
Fusion success rate — every grade
Fuse 9 ×Upgrade chanceResult distribution
Common100.0% (guaranteed)
Uncommon 95.2%Rare 4.76%
Uncommon100.0% (guaranteed)
Rare 96.2%Legendary 3.85%
Rare100.0% (guaranteed)
Legendary 97.6%Immortal 2.44%
Legendary100.0% (guaranteed)
Immortal 99.0%Arcana 0.990%
Immortal50.1%
Immortal 49.9% (no change)Arcana 49.9%Beyond 0.249%
Arcana33.4%
Arcana 66.6% (no change)Beyond 33.3%Celestial 0.166%
Beyond23.1%
Beyond 76.9% (no change)Celestial 23.1%Divine 0.077%
Celestial16.7%
Celestial 83.3% (no change)Divine 16.7%Cosmic 0.017%
Divine9.09%
Divine 90.9% (no change)Cosmic 9.09%
Cosmicmax gradeCosmic is the highest grade — it can't be fused further.
Material planner — how many to reach a grade
Starting grade (what you're fusing)
Target grade
Expected Common items to craft one Immortal
6,561

On average, fusing 9 at a time. Each fuse below Immortal is a guaranteed grade-up; from Immortal on, some fuses stay the same grade and have to be repeated.

Step by step
CommonUncommon100.0% up9.0×
UncommonRare100.0% up9.0×
RareLegendary100.0% up9.0×
LegendaryImmortal100.0% up9.0×
How synthesis works

Synthesis fuses 9 items of the same grade into a single item. The result's grade is decided by weighted odds: a big chance to advance one grade, a small chance to leap two, and — only from Immortal upward — a chance to land back on the same grade.

That same-grade chance is why early synthesis feels free but high-grade synthesis is brutal. Reaching Immortal from Common is four guaranteed steps — 6,561 Commons. The single jump from Immortal to Arcana succeeds under half the time, so it takes roughly 17 Immortals on its own.

The odds above are exact in-game values and are identical for gear, accessories and materials — only the result's item level depends on the recipe and the materials you feed in.