Adding narrative texture to the people and places of Horizon Forbidden West

It wouldn't be unfair to suggest the phrase "living, breathing world" is overused in the video game industry. It's a string of words that evokes a sense of realism, telling players the digital realm they're about to explore is one that feels truly alive. It's easy to understand why it's often used to describe open-world titles in particular, with those projects seeking to deliver expansive adventures set in places that feel like they could persist even when players have left them behind.

How, though, can developers take practical steps to deliver on that heady promise? Speaking at GDC 2023, Guerrilla Games lead living world designer, Espen Sogn, suggested the key lies in creating visible texture by layering in small details that cause far-reaching narrative ripples and hint at deeper meaning.

Make history, not set dressing

Sogn kicked off the talk with a tongue-in-cheek admission: the living world in Horizon Zero Dawn was a "failure." Although Sogn was perhaps being slightly hyper-critical of the first entry in the Horizon series, he explained the title ultimately fell short when it came to world-building because it relied too heavily on NPC behaviours and interactions that existed in isolation. 

He accepted that while the world and those inhabiting it looked vibrant, it ultimately didn't feel vibrant.

For instance, Sogn pointed to a sawmill in the first title as a prime example of that specific failure, noting how players could stumble across a contraption that looked both functional and fascinating–an object that evidently served a clear purpose–but also one that didn't have "a single NPC paying attention to it."

"The settlement NPCs in [Horizon Zero Dawn] didn't feel like they belonged there. They felt like people placed into an environment," added Sogn, noting how separate tribes lacked signature tasks and, despite wearing different clothes, would move and interact with the world in exactly the same way. Those overlapping, generic animations ultimately turned the NPCs (and by extension, the world around them, in Zero Dawn into "set dressing," and the team was keen to remedy that when it began working on Forbidden West.

In order to realize that "living world" the second time around, Sogn's team created tribe-specific animations and resisted the urge to use them everywhere. The team wanted to avoid leaning on "information booth" NPCs to dump exposition on players, and hoped that by ensuring each of Forbidden West's tribes interacted with the world and other NPCs in visibly unique ways, it would hint at rich histories and cultures.

"If you can't get an idea about who these people are by walking around and observing them, I don't think we'd have done a good job," explains Sogn. An example of one of those interactions is how sub-faction of NPCs in the Tenakth tribe will draw their knife from a different place, subtly emphasising their status as warriors.

The Utaru tribe, meanwhile, wiil sit closely to each other when in conversation and in general have clear and obvious disregard for the notion of personal space. It was a design choice that acknowledges the living arrangements of the Utaru, whose decision to build cramped settlements on top of old satellite dishes resulted in them becoming incredibly comfortable with one another.

"Our thinking was that, over generations, they would've gotten very used to living shoulder to shoulder with hundreds of other people. In fact, their inclination would always be to sit as close to other people as possible," says Sogn. "So, what would happened in conversation, for example, is they would have their arm around their friends shoulder and would basically talk nose-to-nose. This idea influenced all the animations we shot for the Utariu, and it gave them a very different feel from all the other tribes."

Sogn explains that the reason those visual hooks work so well at imbuing the world with a sense of realism is because they aren't something that require an explanation. Although there's a rationale behind the behavior, it ultimately doesn't matter if players understand why the Utaru act that way, because they still recognise the interactions as being unique, and understand it must have originated from somewhere.

The very, very slow march of time

When it comes to implementing other interactions like the busy work that makes settlements feel like bustling hubs Sogn says it's also important to play fast and loose with the notion of time. Animations and actions need to be unique and clearly contextualized, sure. But they also need to be designed and implemented in such a way that players won't see–or at the very least notice–repeat offenders every time they visit or linger in a space.

You see, time in video games works differently. In Forbidden West, for example, there is a day-night cycle that very clearly suggests time is moving forward. In reality, the game world won't actually change unless players compete certain quests and progress through the narrative. Accoridng to Sogn, that means NPCs and other objects need to convey the idea of progress while nothing is happening.

"A kind of animation you want to see in a settlement, for example, is people working– they could be laying bricks or painting a wall. That seems pretty straightforward, but it's not because at some point in real life they would actually finish," says Sogn.

"In short, it needs to look like the workers are making progress while not actually achieving anything. One way to achieve that is to make a really long looping animation, so you could have your NPC start painting at one end of a long wall, slowly working to the other side, and then when they get there they turn around and move in the other direction."

Sogn explains another solution is to have two states or positions that NPCs can move between, with a long pause in between. "So, for example, you could have an NPC that just sort of picks up a crate from table then walks over and puts it down on the floor over there and walks away," he says. "Then after a long pause, that NPCs—or even a different one—comes back and picks it up from the floor and then puts it back on the table."

It's a technique that sounds simple, but it's an effective way of creating the illusion that NPCs are working hard all day without actually getting any work done. 

Again, it's all about adding texture to the world. Players are observant, but by layering these small, considered, animations and actions on top of each other it's possible to convince them the people and places around them are part of a vast, ever-spinning ecosystem that existed long before they arrived, and will continue to exist long after they've departed.