A Non-Player Character (NPC) is any character in a game or interactive experience that is not controlled by a human player, instead being governed by pre-scripted behaviors, AI decision systems, or procedural rules. NPCs populate game worlds as shopkeepers, enemies, quest-givers, crowd members, and any other character whose actions are determined by the game system rather than direct human input.

The design and animation of NPCs is a significant discipline within game development, requiring believable movement, contextually appropriate behavior, and visual design that fits the game world while remaining performant enough to run alongside many other characters simultaneously. NPC animation typically relies on skeletal animation systems with state machines that transition between idle, walk, run, interact, and combat animations based on game conditions. Advanced NPC systems use behavior trees, utility AI, or machine learning to produce more dynamic, context-sensitive behavior that makes characters feel less scripted. The visual quality of NPCs often differs from the protagonist to manage performance budgets - background crowd characters use lower-resolution models and simpler animations than story-critical characters who are examined closely.

AI generation tools are increasingly relevant to NPC production, enabling faster creation of NPC character designs, dialogue, and behavior patterns. For creators developing games or interactive experiences with AI assistance, generating varied NPC character concepts, environment-appropriate costumes and designs, and visual references for crowd character types are all practical applications that AI image generation tools support effectively.