Creating believable non-player characters (NPCs) in games presents a persistent challenge for developers, requiring a delicate balance between detailed simulation and avoiding perceived fakery. Philipp Weber, a designer at CD Projekt Red, highlighted this difficulty during The Witcher 3's development in an interview with Edge Magazine.
Weber explained that players are increasingly interested in the intricacies of game worlds, scrutinizing NPC actions and seeking confirmation that their existence is more than superficial. "If a village only has eight houses, people will want to see if the people truly exist in the world or if it's just fakery," Weber stated, noting that this attention to detail "really came to haunt us" during development.
He elaborated on the commitment to making NPCs feel integral to the world. While creating a village of eight houses with functional NPCs might now be achievable in a couple of hours, the process was more arduous in the past. This focus on detail was crucial for maintaining immersion, especially in a game designed to simulate a living, breathing fantasy world.
An example of the complexities involved was the implementation of NPC reactions to in-game events. Initially, when players initiated combat in town, NPCs were programmed to react by dropping their activities and fleeing. However, this system had unintended consequences, such as mothers in the game world dropping their babies when combat started. "For a few weeks, women were just dropping their babies, left and right," Weber recalled.
CD Projekt Red aimed to enhance NPC believability by giving them a range of appropriate activities and allowing them to autonomously navigate the environment. Instead of following fixed paths, NPCs were given "spots of interest" and managed their own pathfinding. For instance, in Novigrad harbor, where 50 sailors might be active simultaneously, developers created 200 potential spots to ensure variety in their routines.
The studio believes that a human touch in design significantly contributes to NPC realism. While system-driven simulations are fundamental to creating believable characters, CD Projekt Red has previously noted a substantial quality difference between manually programmed NPCs and those driven by more automated AI systems, describing the gap as "like a canyon."