PoE2 Desecration: Which Side Does a Bone Land On?
In PoE2 desecration, a bone lands on either side 50/50 when both sides are open. When both sides are full, one non-Fractured mod is removed at random and the new mod goes on that side. To choose the side yourself, use Omen of Sinistral Necromancy or Omen of Dextral Necromancy. ExileDesk switched to this behavior in v0.1.525.
Zundamon
I've never cared which side a bone lands on.
Metan
Some slots, like gloves, only have the Desecrated mod you want as a suffix. If the side misses, your target can't even show up as an option.
Zundamon
That's bad! So how is the side decided?
Metan
Until recently, ExileDesk decided it its own way. We only noticed when we compared it with Craft of Exile.
Which Side Does a Bone Land On?
If both prefixes and suffixes have room, it's 50/50.
Zundamon
50/50? Where is that decided?
Metan
Craft of Exile (CoE) builds its desecration with a random 0 or 1 for the side.
Zundamon
Doesn't the game text say anything?
Metan
Neither the bones nor the Necromancy omens say how the side is picked without an omen.
Metan
Anything unwritten is equally random. That's how ExileDesk reads it now.
What Gets Removed When Both Sides Are Full?
Use a bone on a Rare with both sides full, and one mod is removed at random from all non-Fractured mods. The new Unrevealed mod goes on the side that just opened up.
Zundamon
So it picks a side first, then removes one from that side?
Metan
The other way around. It picks what to remove first, then fills the gap.
| Situation | Side it lands on | What happens |
|---|---|---|
| Both sides open | 50/50 | A random 0 or 1 in CoE's code |
| Both sides full | Wherever the removed mod was | One non-Fractured mod is removed at random, and the bone fills that gap |
Just remember: it isn't "pick a side, then remove." It's "pick what to remove, and that sets the side."
What Did ExileDesk Get Wrong?
The old ExileDesk differed from CoE in both cases.
| Situation | Old ExileDesk | Now (v0.1.525, same as CoE) | Why we changed it |
|---|---|---|---|
| Both sides open | Side picked by the total weight of each side's mods | 50/50 | Nothing in the game says to pick by weight |
| Both sides full | Side picked by weight, then one mod on that side removed | One removed equally from all non-Fractured mods; the bone goes there | It contradicted our 10-10 note, "remove one equally from non-Fractured mods" |
Zundamon
Picking by weight sounds reasonable, though.
Metan
It leans toward the side with more options, so it looks plausible. But nothing in the game says so.
Metan
The full-sides case even contradicted our own note from 10-10. The note was right, and the code had drifted.
Zundamon
When did you notice?
Metan
On 2026-10-16. We took every rule that public information doesn't settle and compared each one with CoE's code.
Metan
We didn't call any API. We only read the code files CoE's page loads by itself, and these two were in there.
Why 50/50?
The deciding factor was the owner's principle: "if it isn't written, it's random."
Zundamon
What did the owner say exactly?
Metan
Roughly: "if nothing is written, the effect just happens as stated, so anything unwritten is random."
Metan
We don't add our own logic where the text says nothing. Picking a side by weight was exactly that kind of added logic.
Zundamon
So when was it fixed?
Metan
In v0.1.525 (10-16), we switched to CoE's behavior. That night the owner confirmed keeping 50/50, and signed off on 10-17.
Zundamon
So you matched CoE on everything?
Metan
Not everything. We matched things like the Omen of Catalysing Exaltation multiplier, but some rules went the other way.
| Rule | ExileDesk now | Compared with CoE | Since |
|---|---|---|---|
| Bone side (50/50, remove one equally) | Same as CoE | Matches | v0.1.525 |
| Omen of Light with Omen of Sinistral / Dextral Annulment | Can't be active together | Differs (the owner decided on 10-17: "Light is already in use") | v0.1.544 (v0.1.525 allowed both) |
| Bones with a Mark of the Abyssal Lord | The bone replaces the Mark; Necromancy omens aren't used or consumed | Matches | v0.1.545 |
We decide whether to follow CoE one rule at a time.
Choosing the Side with a Necromancy Omen
To pick the side yourself, activate a Necromancy omen before using the bone.
Zundamon
How does the omen change the side?
Metan
Just as written. Omen of Sinistral Necromancy makes your next Desecration prefix only, and Omen of Dextral Necromancy makes it suffix only.
Zundamon
What if that side is already full?
Metan
It replaces one mod on that side. ExileDesk has shown "replaces 1" since v0.1.511.
Zundamon
How much does the omen cost?
Metan
Omen of Dextral Necromancy was 7.29 Exalted Orbs (ExileDesk server market, 2026-10-20).
Metan
On gloves, Desecrated-only mods are suffixes only. We counted them in Arcane Surge Desecrated gloves. Here are the glove bones (Ribs) too.
| Bone | Condition | Market (Exalted Orbs) | Note |
|---|---|---|---|
| Gnawed Rib | Item Level 64 max | 6.39 | Cheap, with a limit |
| Preserved Rib | ― | 6.75 | No limit shown |
| Ancient Rib | Minimum Modifier Level 40 | 4,702 | In a different league |
Zundamon
Only the Ancient Rib has a totally different price!
Not yet verified (3)
- Both the 50/50 split and the equal removal follow CoE's code and the owner's "unwritten means random" principle. Nobody counted hundreds of bones in-game.
- The game text doesn't give the side odds either.
- Our sources don't cover the case where only one side is open, or whether Unrevealed and Desecrated mods can be removed when both sides are full.
Metan
Any crafting cost that includes Desecration sits on top of this side rule. Working costs backward is covered in crafting expected cost vs. intuition.
A bone lands 50/50 when both sides are open, and on the side of the equally removed non-Fractured mod when both are full. If your target only exists on one side, settle the side with a Necromancy omen first.
Where the Numbers Come From
Show sources (6)
- 50/50 and "remove one non-Fractured mod equally, land on that side": CoE's code (poe2_desecrate, our 2026-10-16 comparison) and changelog v0.1.525 (poe2db / CoE, engine).
- The old behavior (total weight; pick side by weight, then remove): our Craft of Exile comparison notes (2026-10-16) (engine).
- The owner's principle and follow-up (10-16 night, 10-17 sign-off): the same notes and our crafting rule checklist (2026-10-17).
- Omen of Light with side Annulment (v0.1.525 to v0.1.544), Necromancy with a Mark (v0.1.545), "replaces 1" (v0.1.511): changelog (engine).
- What the Necromancy omens do: in-game descriptions.
- Prices (Omen of Dextral Necromancy 7.29 Exalted Orbs; Ribs 6.39 / 6.75 / 4,702 Exalted Orbs): ExileDesk server market (2026-10-20). Rib conditions (Item Level 64 max, Minimum Modifier Level 40) come from the analyst's handover note (the original screen is not recorded).
Try It Yourself
Use a bone on gloves on the crafting bench to see how the side changes with and without a Necromancy omen.
Related posts
- PoE2 Arcane Surge Desecrated gloves
- PoE2 Desecration weights
- PoE2 crafting expected cost vs. intuition
VOICEVOX: Zundamon / Shikoku Metan
Character art: Shikoku Metan / Zundamon standing art by Sakamoto Ahiru