In early 2007, Jonathan, Erik and I started planning the five-act structure of Path of Exile. By late 2008, specific details had been decided regarding the contents of these acts. Plans like the non-linear layout of Act 2 and the surprise-PvP component to the bandit quests were already laid down. While almost everything we planned was eventually implemented and lives on in modern Path of Exile, there is one aspect that didn't go at all according to plan, and was toned down massively to just become a relatively unremarkable monster type. This news post is the untold story of The Undying.

While planning the monster composition of Act Three, we wanted to introduce an interesting mechanic that would play with the ruined nature of the City of Sarn. As the first Act that had buildings, Act Three contained transitions from indoors to outdoors within the same map. We wanted to take advantage of this by designing a monster type that strongly played into this mechanic.

The plan was this: City Stalkers (later renamed to The Undying) were undead beings who roamed the shaded areas of Sarn, wrapped in bandages. They couldn't tolerate the light and would never leave the shade. In return for their restricted movement areas, they were incredibly powerful and would destroy players in combat until an appropriate countermeasure was earned.

We love surprise monsters and the suspense that they can create. This is why we have Sand Spitters emerging from underground, Statues coming alive and Rock Golems (internally called Moss Monsters) that form out of piles of rocks when you approach. In order to keep the suspense up, there are of course statues that don't come alive and inanimate piles of rocks that are just there to distract you.

Our intention with the player's first experience of Act Three was that the first area would be very quiet, with no monsters to fight outdoors. Upon venturing into the shade, though, players would be charged by deadly City Stalkers and would have to retreat to the safety of the sun. Their experience with the rest of the Act would involve a game of caring very much which areas were shaded, while occasionally being forced to step out of the light to travel between buildings. Because of their early encounters with the City Stalkers, they would fear every moment spent out of sunlight, as it is one step away from being swarmed by the deadliest monsters in Path of Exile. We intended for City Stalkers to have immense life regeneration, preventing players from making reasonable progress past them.

Later in the Act Three storyline, players would earn the ability to harm City Stalkers, allowing them access to areas that were previously off-limits (similar to what you'd encounter in a game like Metroid). Suddenly the one-sided fights would become more fair, and revenge could be exacted. Our intention was that this ability would come in the form of a white Support Gem which, while supporting your primary damage skill, would let you harm City Stalkers and would turn off their life regeneration.

We found this idea really compelling because we liked to experiment with extreme ideas. We wanted Path of Exile to be brutal, and took every opportunity to achieve that. Unfortunately, there were many problems with the above plan, which look obvious with hindsight and experience:

• Directing players into a lethal encounter to make sure they understand it is dangerous was probably too aggressive, especially with a hardcore permadeath mode in the game. Some players would not understand that this was a sign that they needed to go elsewhere and find a way to become powerful, and would have instead become concerned that the game is too difficult and it's literally impossible to progress. We saw these exact concerns later from encounters that were far more winnable than how we intended this one to be.
• If the City Stalkers can't go in the sunlight, then what stops you kiting them around and hitting them while you're out of the shade? While they regen too fast to die, they certainly look like noobs standing in the shadow and not doing anything. There would have been a lot of work to make this realistic and feel good.
• If you recall the early versions of Act Three (prior to the 2.0.0 and 3.0.0 simplifications of it), you'll remember it was already a rabbit warren of fetch quests and obscure instructions. Adding to this the inability to travel in some areas and the requirement to later go back to places you've already been was not a step in the right direction.
• While it was cool to use a Support Gem to be able to kill the City Stalkers, this would disrupt people's builds substantially. Having to spend an Act playing without one of your existing Support Gems was too much for many builds. It's also really hard to communicate. We initially intended the Baleful Gem and Maligaro's Spike to have a similar arrangement, where you kill Lorrata with the Spike socketed with the Gem, but we never got around to this for similar reasons. Maybe one day!
• Another practical concern was how difficulty levels were handled (this was eight years before we removed them - at the time, Path of Exile had Hard, Cruel, Ruthless and Merciless as its difficulty levels). If you had the white Support Gem from the first difficulty level, what prevented you from taking it to the second one and immediately being able to kill the City Stalkers? Our plans for the act were complex enough that being able to immediately fight them wasn't really an option. We also wanted to avoid having four copies of the gem, as that'd be confusing. We couldn't take the gem away when you finished the act, because you might need it to go back there to farm some experience, help a friend, or finish a side-quest.

And so, the idea of City Stalkers fearing sunlight was scrapped. They were named The Undying and do make up part of the monster composition of modern Act Three, but without the crazy mechanic that almost made it in.

"Stay out of the shadows. They bite." -- Hargan