Paper: Common Game AI Techniques

Common Game AI Techniques

Steve Rabin [2004]

In this paper, the author describes the most common techniques used in the industry and gives a game application example of each one of them. Here is a list of the techniques described in the article:

• A* Pathfinding: Find the cheapest path through an environment.
• Command Hierarchy: Strategy to deal with AI decisions at different levels. Modeled after military hierarchies.
• Dead Reckoning: Predict a player's future position based on current position, velocity and acceleration.
• Emergent Behavior: Behavior that wasn't explicitly programmed but emerges from the interaction of simpler behaviors.
• Flocking: Technique for moving groups of creatures in a natural manner.
• Formations: Group movement technique that mimics military formations.
• Influence Mapping: Method for viewing the distribution of power within a game world.
• Level of Detail AI: Optimization technique where AI computations are only performed if the player will notice them.
• Manager Task Assignment: A single agent makes decisions and assings tasks to agents best suited for the task.
• Obstacle Avoidance: Use of trajectory prediction and layered steering behaviors to avoid obstacles.
• Scripting: Specify a game's logic outside the game's source language.
• State Machine: A finite set of states and transitions where only one state can be active at a time.
• Stack-Based State Machine: Same as State Machine but remembers past states so they can be retrieved if current state is interrupted.
• Subsumption Architectures: A specifict type of agent architecture that separates the behavior of a single character into concurrently running layers of State Machines.
• Terrain Analysis: Analyze the terrain of a game world in order to identify strategic locations such as resources, ambush points, etc.
• Trigger System: Simple system that allows if/then rules to be encapsulated within game objects of the world itself.

Each one of these topics is further explained in the paper that you can find in the book AI Game Programming Wisdom 2.

Rabin, Steve (2004). Common Game AI Techniques. In Steve Rabin (Ed.) AI Game Programming Wisdom 2 (pp 3-14) United States, Charles River Media Inc.