Uniques are not all of the same rarity
When an item is generated rarity is determined first, it can be white, magic, rare or 1 of some number of unique rarity bands. exactly how many tiers of unique there are has not been publicly revealed.
If the item is unique, a unique is chosen from the chosen unique tier.If the item is not unique, then base type etc is determined.
In the case of chancing, base type never needs to be determined. however if a unique tier is chosen for which no unique of that base exists, then the item defaults down to a rare. So the existence of multiple uniques for a base only affects the probabilities of getting those uniques if more than 1 is on the same tier list.
So to be clear, in a world where infernal mantle did not exist, the chances of getting shavs would remain the same. All that would happen is you would get a rare on those rolls where you would have gotten infernal mantle.
Oct
This is my honest feedback - Path of Exile Designers
This game has a unique feel and it is not easy to offer a self contained and well defined experience nowadays. Path of Exile is grim, compelling and harsh, in a good way.
Nov
The new Exile Mods would have to be significantly better than the current
therefore, the current perfect gear will always be better, unless GGG decides to add gear that you can use less than 300 chaos on.
Jan
How to do Righteous Troll build in Path of Exile 2.5.x Patch
Chieftain with 9 endurances would have 13.5% regen not 15%. While chieftain would have more regen and probably a bit more damage, but he wouldn't be as tanky against physical damage.
Oct
Patches, Updates, Build of the Week & More At Path of Exile
This week's Path of Exile: The Exiled Tribune is a good meaty one with news about forthcoming v2.4x patches and changes to the difficulty levels for the game with the arrival of v3.0 in 2017.
Apr
poe4orbs:PoE 3.14 Ultimatum Server Issues Fixing Progress
PoE 3.14 Ultimatum has been released for a few hours, but a large number of players have encountered server issues that are difficult to solve. GGG gave the latest news about when the server will be repaired normally.
Jan
[3.13] Path of Exile Ritual League Starter Guide
PoE 3.13 Ritual is a league with the theme of regional fight. Kill all monsters in the area to get rich rewards. Hope this latest PoE 3.13 Ritual Gameplay Guide prepared by poe4orbs can help you leveling.