Developing believable non-player characters (NPCs) in open-world games presents ongoing challenges for developers, a fact that CD Projekt Red faced during the creation of The Witcher 3: Wild Hunt. Quest designer Philipp Weber shared an anecdote about the game's NPC behavior, specifically how implementing fear reactions led to a peculiar bug where mothers would drop their babies.
Weber explained that the team's focus on creating a reactive world meant that even in small villages, players expected inhabitants to act as if they were real. "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 in an interview with GamesRadar. "Lots of people nowadays are interested in those kinds of details, and it really came to haunt us." While modern development tools might make this easier, the team's relative inexperience with such detailed NPC behavior at the time proved challenging.
Instead of scripting specific paths for every NPC, CD Projekt Red opted to define points of interest for them to navigate towards. This allowed NPCs to dynamically choose their next activity, such as switching from woodcutting to carpentry. For instance, the 50 sailors in Novigrad harbor were given 200 possible locations to interact with, ensuring variety even if all were active simultaneously.
However, this system had an unintended consequence when the team implemented fear reactions. When Geralt engaged in combat, NPCs were programmed to flee. This general fear response, applied broadly, caused the game's AI to interpret the situation as a dire emergency, leading mothers to abandon their children. "For a few weeks, women were just dropping their babies, left and right," Weber recalled. This bug persisted until the developers could refine the NPC AI to distinguish between general panic and specific threats to a caregiver's responsibility.