Using behaviour patterns to generate scripts for computer role-playing games

• Author / Creator

  Cutumisu, Maria

• Character behaviours in computer role-playing games have a significant impact on
  game-play, but are often difficult for story authors to implement and modify. Many
  computer games use custom scripts to control the behaviours of non-player characters
  (NPCs). Therefore, a story author must write fragments of computer code
  for the hundreds or thousands of NPCs in the game world. The challenge is to create
  non-repetitive (more entertaining) behaviours for the NPCs without investing
  substantial programming effort to write custom non-trivial scripts for each NPC.
  Consequently, current computer games mostly rely on simplistic non-interactive
  behaviours for NPCs. This research describes the design and implementation of
  a novel behaviour model for interacting NPCs, based on generative design patterns,
  that requires no manual script writing. In this model, NPCs assume different
  roles during the story and select behaviours based on static probabilities or dynamic
  motivations. We also devised a reinforcement learning algorithm, ALeRT, based
  on Sarsa(lambda) and we extended our behaviour model to support behaviour selection
  based on learning. In our model, an NPC can exhibit proactive, reactive, or latent
  behaviours that may be independent or collaborative. This behaviour architecture
  supports behaviours that can be interrupted and resumed based on priorities. The
  implementation of this model produces scripting code for BioWare Corp.'s Neverwinter
  Nights computer role-playing game.

• Subjects / Keywords

  • NPC behaviours
  • Behaviour patterns
  • Reinforcement learning
  • Computer role-playing games
  • Content generation

• Graduation date

  Fall 2009

• Type of Item

  Thesis

• Degree

  Doctor of Philosophy

• DOI

  https://doi.org/10.7939/R30W2K

• License

  This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.