rpg

Witcher 3 designer: NPC realism caused odd bugs, fixed with spot-based AI

CD Projekt Red faced early challenges making NPCs believable in The Witcher 3, with simplistic reactions producing immersion-breaking behavior such as mothers dropping babies when NPCs fled combat. Developers moved from fixed paths to a spot-of-interest system so NPCs choose their own routes and activities. This system uses many more option points—for example, 50 sailors at Novigrad harbour can pick from 200 possible spots—reducing repetition and convincing players the world is alive.

• Players closely inspect small settlements, so NPC authenticity had to mask the game’s limited set pieces rather than reveal "fakery"
• Initial NPC reactions were crude: when combat prompted civilians to flee, they sometimes dropped held items and even babies during testing
• NPCs were changed from scripted paths to spot-of-interest pathfinding so characters pick activities and routes dynamically
• Example implementation: 50 sailors at Novigrad harbour are given 200 possible spots to choose from, and building an eight-house village with that system can be assembled in about two hours