Understanding Everything NPCs Can Do: Metrics for Action Similarity in Non-Player Characters

J. Timothy Balint, Jan M. Allbeck, Rafael Bidarra

Research output: Chapter in Book/Conference proceedings/Edited volumeConference contributionScientificpeer-review

3 Citations (Scopus)
30 Downloads (Pure)


Non-Player Characters (NPCs) have actions that allow them to reason about what they can do in a game and how they can do it. The background information about what they can do are the components of the action, and how they can do it is the form or shape of an action, which may be built up from several sub- actions. The components and shape of an action must be fully defined in a game, which can be tedious when several similar actions are needed. Furthermore, as the number of nuanced actions grows, more pressure is placed on an already constrained reasoning system. By discovering the similarities between actions an NPC can do, a given action set can be intelligently organized with similar components being generalized using an action taxonomy. To understand the similarity between actions we have developed measures of action similarity based on their constituent components and form. From this, we
discover a metric to determine the generalization ability of an organization strategy for an NPC action set. We examine the use of our measures on a previously developed action set to show the nuances between those actions. Lastly, we find that intelligently organizing actions has a positive effect on virtual character reasoning abilities.
Original languageEnglish
Title of host publicationFDG'18
Subtitle of host publicationProceedings of the 13th International Conference on the Foundations of Digital Games
Place of PublicationNew York, NY
PublisherAssociation for Computing Machinery (ACM)
Number of pages10
ISBN (Print)978-1-4503-6571-0
Publication statusPublished - 2018
EventFDG 2018 : 13th International Conference on the Foundations of Digital Games - Malmo, Sweden
Duration: 7 Aug 201810 Aug 2018
Conference number: 13th


ConferenceFDG 2018
Abbreviated titleFDG'18

Bibliographical note

Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care

Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.


  • Artificial Intelligence in Games
  • Reasoning
  • Behavior Organization


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