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Path of Exile's Delirium Expansion Is Looking Incredible

Player depth, customization, combat, passives, and more

Poorna Shankar Posted:
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Last week, I had the opportunity to speak with Path of Exile Managing Director, Chris Wilson, for nearly an hour about their upcoming expansion, Delirium. Our conversation ranged from the ethos behind the expansion, to new mechanics, the passive tree, and much more.

The Ethos

First things first. Delirium is set to release in March. Chris explained the ethos behind Delirium and the approach Grinding Gear Games is taking to the expansion, specifically by playing into two key elements players love about Path of Exile.

The first is action combat which rewards you for taking risks with your character. This resulted in the team understanding that players like pushing characters in “actual RPGs” further and further,

“And so one of the things we have strongly as a theme in Delirium is the concept of you really wanting to go deeper and deeper in terms of making it as a hard experience for your player. And so there's a lot of temptation there.”

That word, “temptation,” is really the heart of Delirium. The team wants you to feel tempted by better gear, better passives, cool abilities, etc. In fact, Chris explained that this idea of temptation is also there for players to make the wrong decisions,

“Yeah, tempting is a good way to describe it. We both need to tempt people for marketing reasons so they play the game, but also tempt them to make the wrong choices while they're playing. So that they have hard questions, you know? Should I be playing this way? Should they play that way, maybe play multiple times?”

The second key element the team is approaching for Delirium is character customization, and specifically, expanding the passive tree,

Path of Exile is already famous for the different build options around the crazy passive tree and all that kind of stuff. But the system that we're adding in Delirium for this, this passive skill gem, passive skill cluster draw system that we're doing, really takes that to a new level, and it's probably the most impactful change we've made to character building and Path of Exile for maybe three or four years now.”

Combat, Risk, and Mirror of Delirium

To address that first element, deeper combat to push players, the team developed a mechanic called the Mirror of Delirium. This Mirror exists in each area of the world. Once you encounter one of these, you’ll see a ghostly visage your character reflected back. Interacting with the Mirror will thrust you in a state of Delirium (get it?) for a minute.

Upon entering this state of Delirium, the immediate area around you becomes completely shrouded in this unholy fog. Having seen this fog in action, it genuinely looks awesome. In fact, the team has a member on staff with a graphics PhD who came up with this fog tech,

“That’s from the graphics PhD guy,” explained Chris when I expressed my excitement for the mist, “We basically said to him, do some math make some fog, and he's come up with that. I mean, it's aimed for misty greyed out areas in the sequel [Path of Exile 2], but being able to use it as a visual indicator of the difficulty during this league is of course a really good bonus.”

So what exactly happens in this mist? Any existing monsters in this mist of Delirium now gain new abilities, and new monsters are spawned. In fact, the deeper you go into the mist, the density of the monsters increase. These monsters also have mods on them, further complicating matters.

“Basically it just ramps up the difficulty massively, and gives you a lot of opportunities, you get your character killed. Now, this gets harder and harder as you get further away from the starting point basically get deeper into the Delirium and madness and more things start to manifest.”

In fact the difficulty of these monsters is even tied into how these monsters react with the mist. For example, some of the monsters could explode upon death, or just manifest all manner of unholy things out of the darkness,

“There are different bosses that spawn that hunt you down. And basically the further away you get from the origin [of the Mirror], the more spooky horror stuff happens as your character becomes more and more mad and confused, and it gives you a lot of opportunity to get in over your head. Like, it's possible to encounter some very difficult bosses here or to have existing encounters really amped themselves up to the point where you can't deal with them anymore.”

Because there is one Mirror per world area, you don’t necessarily have to interact with it upon immediately running into one. You could in theory come back to it later and play through it should you wish,

“There's a slight logistics issues within playing online, too, due to the fact that the areas you've been through will close up for a period of time of being empty. But yeah, if you juggle that correctly, then you absolutely could go and play a bunch of areas back to back.”

This Delirium mechanic affects every encounter in the game, including Act Bosses. So yes, you can absolutely fight a boss in the Delirium realm and this has a substantial effect on the boss, its difficulty, and the rewards you can receive.

Chris also explained that the team made it a point to combine the Delirium league with all past league content which has already been integrated into Path of Exile. For example, this Delirium mechanic can be combined with the Ambush Strongboxes, Betrayal Encounters, Incursion and Beach mechanics of past leagues. Again, the goal here is to push players.

“Basically, it's a lot of stuff that players are already familiar with and the game amped up to hard mode because they're doing it after tagging the Mirror. And so, we're trying very hard to make sure that it's just an additional layer on top of the entire game rather than a standalone thing that you do. That's kind of samey.”


The second major gameplay element coming to Path of Exile in Delirium revolves around rewards and the passives tree. Each are you’ll enter contains a specific type of random Delirium reward. These can include currency, map items, rare armor pieces, and more.

If you happen to kill enough monsters when you’re in the Delirium mist, you’ll receive one of those items. From here, your progress is reset at which point you can earn another item, but with diminishing returns.

“So this means as you're playing through the Delirium encounter, you'll get at a slow progression, the type of item that's themed into this encounter,” explained Chris, “And so by itself that motivates players to you know, kill a bunch of monsters and do as well as they can, I mean, obviously, the Delirium monsters drop pile of items and they very rewarding, especially the further away from the Mirror you get. So, at its base value, that means that players will see themed stuff and get to receive it, but occasionally, you'll get something that's quite a lot more valuable than the other times. Like you'll find a Delirium encounter that rewards you with say, unique items.”

This ties directly back to that first design goal of Delirium: push players.

“And in that case, you really want to push it because you're getting a special reward that's very uncommon. You want to kill as many monsters as you can, and that'll cause players to overcommit to getting into really dangerous situations and pushing their characters really hard.”

Naturally, when you combine this reward structure with the notion of pushing players to the limits, you arrive at endgame. Endgame maps contain these Mirrors of Delirium just like the rest of the game, but there’s one key difference.

You can find Orbs of Delirium which can be applied to maps to uniformly apply Delirium to that map. Each additional Orb increases the density, dramatically increasing its difficulty and how rewarding it is. Each Orb of Delirium has a reward theme, and sets the Delirium reward type for that map.

For example, you can apply several orbs to a single map, thus drastically increasing its difficulty. This means that it could drop currency and unique items as additional Delirium rewards. In effect, skilled players can create some seriously difficult endgame content and overexert themselves, something Grinding Gear Games is happy to encourage.

However, the rewards go deeper than that. Any maps affected by these orbs will drop Simulacrum Splinters. 100 of these splinters combine to create the Simulacrum, an item that enabled access to a special new end-game challenge. Just what this challenge is, Grinding Gear Games won’t say.

“And this is kind of like the ultimate Delirium encounter with cool stuff going on. We're not saying what happens, but it's pretty special, and it is something that players will look forward to. And normally, it's rare for us to get time in an expansion cycle to go and make an additional endgame encounter in addition to whatever we put on the map areas. So this is something we're quite pleased to be able to fit in. And this is one of those things that realistically, a lot of players are gonna have experienced by watching on Twitch rather than actually getting a chance to play themselves because it's quite hard to get there.”


Of course, perhaps one of the most famous mechanics of Path of Exile is its insanely vast passives tree, providing theory-crafters endless fun tinkering with the just the right combination of skills to create truly ludicrous builds. In Delirium, this passives tree is set to get new additions in the form of cluster jewels.

In essence, cluster jewels will expand your skill tree. These can be placed on the external sockets of the tree and create new passive skill clusters which can themselves contain more sockets. According to the team, these cluster jewels are the biggest change to how you can build Path of Exile characters since the introduction of Ascendancy classes in 2016. Of course, jewels are randomly generated and can be rerolled by players to make ones that are perfect for their build.

There are three different socket sizes: small, medium, and large. You can fit two small jewels in a medium slot, and two medium jewels in a large slot. As you can imagine, this means you can create entire branches of clusters hanging off the edge of your passives tree,

“And so and then you can do this multiple places on the tree. If you really care to, like if you want to just make your own tree and not care about the one that we made for the player, then you can absolutely get a lot of jewels and do that.”

Keystone passives are another new addition because these can radically change your character. Chris gave me an example of one such passive called Hollow Palm Technique,

“And in this case, it basically says that while you have nothing in your hands and the gloves on, you're a martial arts expert, you attack really fast and you do additional physical damage based on how dexterous you are. And so basically, if you get this and then forgo your weapons and gloves, you're like a monk, ninja’ing around doing stuff. And so this is the case that if a player wants to play that play style, they just need to find this jewel, find an appropriate place on the tree, work out the opportunity cost of forgoing their weapons and gloves, blah, blah, blah. And suddenly they're a ninja.”

Turning Things Up

Once again, this all ties back into pushing players and tempting them with such conflicting risk/reward. Do you forgo your weapons to be some mad Path of Exile ninja? Chris explained that it’s these types of things they want players to discover and go nuts over,

“And so we try very hard to bury this kind of stuff in there where a player will just randomly discover it one day and say, ‘Holy shit, I'm going to do this now.’ And then other people say, ‘How did you do that?’ And they explain something complicated.”

Our conversation naturally steered towards player choice and the flexibility offered by Path of Exile. From everything I’d seen, Delirium was a real push into giving players that depth and choice while dialing things up to 11. As Chris explained,

“And the important thing here is you getting these items randomly, and they're different for each player. So while people will Google how to make Path of Exile character and then follow a guide, the guide can't tell you how to get the specific items like this. And so it means there's a level of uniqueness. Even if the players are trying very hard just to copy an established thing, they still have to make decisions for themselves, they still get something that other people don't have and have to take advantage of it”

When taken all of this into account – the entire Mirror of Delirium mechanic, the nature of monsters, the layering of Delirium on top of existing content, the orbs, the splinters, and the cluster jewels – only one thing really kept cropping up in my mind: temptation.

See? I told you this was a recurring theme. It seems that every single thing Chris and his team have added to Delirium is there to tempt the player and push them to make uncomfortable decisions. And this experimentation, this constant pull of known vs unknown, is at the very heart of Path of Exile and has been tuned to truly insane levels.

It will take a far better player than me to probe the depths of the systems introduced by Delirium. But damn, am I excited to see what the community builds.


Poorna Shankar

A highly opinionated avid PC gamer, Poorna blindly panics with his friends in various multiplayer games, much to the detriment of his team. Constantly questioning industry practices and a passion for technological progress drive his love for the video game industry. He pulls no punches and tells it like he sees it. He runs a podcast, Gaming The Industry, with fellow writer, Joseph Bradford, discussing industry practices and their effects on consumers.