Reputation Systems for Non-Player Character Interactions Based on Player Actions

In digital games there is an emphasis on the idea of quest completion; by completing a quest the character wins resources from the giver of the quest, they also will gain a reputation among the Non-Player Characters (NPCs) for its completion. However, this reputation currently propagates across the game world in an unrealistic manner; many NPCs will know of a completion of a quest many townships over without a narrative rationale. In this paper, we examine a method for allowing NPC interactions to spread reputation in a game world from an initial witness point of a quest completion to all other NPCs. This model is examined in a series of connected graphs: size five models, small world graphs, and graphs developed from digital games. Tests show that propagation of the information is highly dependent upon easily established properties of interactions, such as the graph regularity, average degree, and diameter. Further, real game graphs demonstrate that information generated in high population hubs can be propagated faster than that generated in smaller quests from outlying areas.