As with all league releases, in Path of Exile: Delirium we introduced a number of unique items. For this news post we asked our design team to share their thoughts and processes behind creating these unique items.

Our core goal for modern unique design is to create an item that you'd want to pick up and use, either by creating a new way of playing or enhancing a certain playstyle. For League uniques, many items are intended to be widely usable at a lower level of progression, while being greatly desirable for very specific builds late in progression. There are always exceptions to the rule though!

Keystone Jewels

The Keystone jewels were created from a long list of over 30 suggestions by designers, many of which weren't possible. More build-specific than normal keystones, these ones aimed to create or enhance niche interactions that could potentially promote new builds.

One with Nothing and its keystone Hollow Palm Technique were the special case; originally suggested by an effects artist, it underwent a variety of design iterations. We had to make sure we could allow it to co-exist with Facebreaker, so the original design disabled item slots and had specific restrictions on each of its stats. This was far too wordy, so to clean up the description and prevent potential problems with restricting item slots, the "Unencumbered" state was created. Unencumbered means that you currently have no weapon, gloves, quiver or shield equipped, a condition we could use again in future.

The goal was to create a monk or frenzied melee theme, and the Unencumbered state facilitated us doing this in a way that created an interesting restriction which let us give the Keystone a huge amount of power. Testing showed that it was very powerful for leveling, and we worked to lessen this somewhat during its development by lowering the attack speed multiplier and increasing the added damage to compensate, but we couldn't reduce it further without compromising the design.


Voices was one of the first Cluster Jewel designs we created, before even a single notable was formulated.

It was originally revealed with one blank passive and three jewel sockets. During the iteration of cluster jewels it became clear that it was a very powerful unique, especially with only one small passive. Because of this, we created versions of the unique that had more blank passives to have some versions of the item require more investment than others.

We avoid balancing entirely through rarity, but the nature of this jewel was so interesting that we didn't want to minimise what it could achieve. It became the rarest unique available from the Simulacrum rather than having its power changed. This was a special case for a unique that was only really acceptable because it could only reach its true power when using many other Cluster Jewels.

Split Personality

Originally designed as a Small Cluster Jewel, we quickly decided that the jewel was more interesting if it could go anywhere in the tree and would be best not to have the limitation of being socketed on the outermost part of the tree like Cluster Jewels. We started by adding every common flat benefit (attributes, defences, life, mana and accuracy) to the jewels to see if there was enough variety, and that was able to produce a number of interesting items for builds that focussed on stacking those bonuses while leaving space for similar unique designs in the future.


For a long time, this Medium Cluster Jewel was designed as a jewel that gave no direct bonuses, but buffed the strength of Small and Large Cluster Jewels attached to it. This turned into a nightmare to both describe and make work, so we brainstormed and immediately came up with the current design of having three random notables. At first, it had four random notables, but that was far too powerful for the point investment.

Algor Mortis

These gloves were designed with the goal of creating a new playstyle involving weaving a cold area skill between your lightning damage skills, with a powerful damage increase as a bonus reward. They're also special in that they're the first item to let you inflict the Sap Ailment without preventing Shock (A lightning based ailment that lowers enemy damage). The alternate ailments are special mechanics we usually only grant at the cost of a core elemental ailment, but the unique playstyle this item promotes made Algor Mortis a good place to grant Sap as a special reward for building around the item.


The "Snipe" skill from the Assailum unique was designed in a way that could potentially allow it to become its own support gem, if it was popular enough. It was originally designed as a Support that turned any bow skill into a Channelled skill, but was changed to work as a Channelled Skill that could trigger Supported bow skills to prevent having to rebuild many bow skills to be able to be directly channelled.

During development the helmet had a damage multiplier to skills triggered by Snipe in addition to granting the Vicious Projectiles Support, but as the skill multiplier on Snipe would never be directly visible (since there was no gem!), we combined the two multipliers into one, giving the helmet the damage of a 6 link item in a more concise way.


This item was created to fill the role of a melee-focussed item, as it was designed after Algor Mortis (designed for a spellcaster build) and Assailum (designed for a ranged build). Perfidy was designed with the Champion in mind thanks to their affinity with Banners and their passive that removes their reservation cost. The Master of Command Cluster Jewel notable was designed to lower the cost of using two Banners with other ascendancies, giving it the potential to be more accessible to more builds.

Beacon of Madness

This item was designed early during Delirium's development, but was built around a mechanic that was later removed from the league as it added unnecessary complexity. It was then redesigned later in development to be three uniques based on the debuffs applied by Delirium monsters, providing potent bonuses that we usually wouldn't give away on a single item. However, these bonuses came at the cost of having to skillfully manage debuff uptime.

The three variations of Beacon of Madness received a supplemental effect after being revealed, as further discussion made it clear that the item should be a little more well-rounded. We gave each variation an extra stat that worked when Glorious Madness wasn't active.

Uniques will always be a core part of what makes Path of Exile so interesting. They give you something to strive for, something to inspire new builds, and something to add a little bit of flair and flavour to the game. As the game grows, new designs become possible and new ideas are formed. We hope you've enjoyed this glimpse into our development process, and perhaps this has given you a spark of an idea for what build you're going to try out next.
Posted by 
Grinding Gear Games

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