Game AI Fundamentals
What is Artificial Intelligence (AI)?
• Not easy to answer…
• “Ability of a computer or other machine to
perform those activities that are normally
thought to require intelligence” (from
dictionary)
• “Process” or “science” of creating intelligent
machines
• Artificial “brains” that carries out intelligent
behaviour
Perspectives of AI
• People study AI to:
▫ Gain insight into nature of human intelligence
▫ Create machines that exhibit some form of
intelligence
• So…do game developers need to STUDY AI?
How do we know…
• …if a machine is “intelligent”?
▫ How close is it to human intelligence?
▫ Requires the machine to have conscience and
emotions?
▫ Ability to solve a problem that humans can solve?
▫ Ability to learn and adapt to new situation?
• Turing Test
Weak AI vs. Strong AI
• Strong AI – Produce machines that with an
intelligence that match or exceed that of humans
• Weak AI – Produce machines that are able to
“act” intelligently
Chinese Room Argument
• Does the machine literally understand Chinese? (Strong AI)
• Is the machine simulating the ability to understand
Chinese? (Weak AI)
Deterministic vs. Nondeterministic
• Deterministic AI
▫ Behavior is specified and predictable, no
uncertainty
▫ Fast, easy to implement, Gameplay limitations
• Nondeterministic AI
▫ Behavior has a degree of uncertainty, less
predictable, learn and extrapolate from experience
▫ More burden of implementation and testing
▫ Gameplay evolution, emergent behavior
Established Game AI
1. “Cheating” – most widely used technique,
abusing this can destroy gameplay.
2. Finite state machines
3. Fuzzy logic or Fuzzy state machines – improve
unpredictability, reduce burden of too many
rules
4. Pathfinding – simple shortest path navigation,
terrain-based/obstacle-based extensions
5. Rule-based, Probability-based decision making
Millington’s Model
Future of Game AI
• The next big thing: Learning – Bayesian
techniques, NN, GA
▫ NPC behaviors are nondeterministic
▫ Game AI can evolve, learn and adapt the more it’s
played
▫ Implementation/debugging challenge
• Artificial life and other Emergent AI