The term “non-player character” originates from tabletop RPGs, where any sentient being who wasn’t in the adventuring party would be incarnated by the hard-working dungeonmaster. Over time, it’s come to take on a more nuanced meaning, excluding enemies and hostile forces to include both computer-controlled allies as well as background characters—shopkeepers, quest-givers, and cannon fodder. It’s basically impossible to think of a modern game that doesn’t have NPCs in one form or another.
Today’s games have a lot riding on their NPCs. While weird behavior from them is good for viral YouTube videos, it can also pull a player right out of their immersion. Developers have been polishing their techniques for creating believable computer people for generations, and Ubisoft’s Watch Dogs: Legion, out now, might represent a huge step forward.
Thought Process
One of the biggest challenges for creating a digital world that seems realistic is human behavior. Developers have taken numerous paths toward believable human non-player characters, but there are a few main philosophies that inform nearly all of them.
The Scheduler. This is seen in a lot of role-playing games, and it first raised its head in Lord British’s seminal Ultima series. Noticing that human beings typically spend their days according to a fairly defined schedule, Origin’s designers tied them to Brittania’s day/night cycle. If you wanted to visit a blacksmith at work, you couldn’t do it after sundown; by then he’d probably retired to the pub for some mead. It was a simple change that meant a lot in terms of immersion.
The Situational. Most modern open-world games work this way—the game only loads in NPCs and thinks about their behavior when it’s relevant to the player. In titles like Grand Theft Auto, you’re basically always guaranteed a certain amount of traffic and a certain number of pedestrians to hassle, no matter what else is going on in the world. These NPCs are loaded in the player’s vicinity, leaving the rest of the city blissfully empty. Once they’re invoked, they can have a number of reactions to stimuli, but they have no long-term goals or plans.
The Sim. Easily the most promising form of NPC, these characters run using simple goal-oriented artificial intelligence so their activities aren’t determined by a proscribed set of instructions but rather adapt to their circumstances. The name comes, of course, from Will Wright’s legendary series of little computer people. These behaviors are often triggered by what’s called a “state machine,” which measures internal and external factors to select from a menu of preset behaviors, like finding food or fleeing violence.
Many games also use a hybrid approach of these methods—characters may have macro-level schedules, and then make simulation-driven decisions on a moment-to-moment basis, for instance.
Everybody Is You
What makes Watch Dogs: Legion so fascinating in its approach to non-player characters is how it shatters the boundaries surrounding them. Each and every resident of the game’s futuristic, dystopian London not only has a daily schedule and a robust artificial intelligence driving them, but can also be transformed into not just an ally, but a playable character. Even more fascinating, the process of recruiting them is intimately tied to their narrative activities and backstory.
In the game, you play a representative of hacker collective DedSec, framed for an act of terrorism. London is entrapped in a net of constant government and private sector surveillance, and the people living there have conflicted feelings about it. Using your computer hacking skills, you can perform research on anybody you see, learning their individual wants and needs. Those also figure into how you approach them. Some might be sympathetic and join DedSec easily, while others require you to prove your bona fides. And none of these are pre-programmed events, but rather generated by the game so every player has a different experience.
Legion manages its NPCs through what it calls the “Census” system, a tally of attributes and relationships that are built as they interact with the player and the world. While the majority of people you see in the background of your adventures are blank slates, as you play they’ll start to pick up more detail. Hurt an innocent bystander during a firefight and their friends and relatives will see their attitude toward DedSec darken. If that attitude becomes too negative, they won’t ever be recruitable, and will influence other people in their social circle the same way. Games advertise that “your actions make a difference” all the time, but in this case it’s true on both a macro and micro level.
Once a person has been brought into DedSec, they can be chosen for player control at any time, even in the middle of a mission. But when you don’t call them, they go about their daily lives as normal, lending even more verisimilitude to the game’s virtual London. And they’re not just interchangeable cannon fodder to be used as extra lives in case you fail in the line of duty. Their character traits, occupation, and skills determine their usage in the field. Recruit a football hooligan and send him into a situation that requires street brawling and zero subtlety, or a beekeeper (really) with a hive of tiny drones.
It’s a fascinating evolution of Ubisoft’s sandbox model, which previously forced gamers to play as carefully focus-grouped main characters. The ability to find a person in Legion’s virtual London who you want to serve as your avatar in the storyline and bring them over to your side really seems like a quantum leap forward in how video games tell stories, and the developers have commented that this is only the first step in what they see as an ongoing project. Future games on next-generation systems will be able to handle networks of relationships that are even more complex and robust, with longer memories and more nuance.
What could this mean for the next Watch Dogs game, or Ubi’s other franchises? Even without the ability to recruit NPCs, the Census system adds a layer of unpredictability and vibrance to everyday crowd scenes. Computer-controlled characters with their own hopes and fears operating independently in the background isn’t going to be the sole selling point for a game, but they represent another step forward in creating immersive simulations that feel realistic. Think about an Assassin’s Creed game where massaging those relationships gets you closer to your targets, for instance. We’re excited to play Watch Dogs: Legion, but we’re even more excited to see what the team does next.
