18 Embarrassing Game AI Bugs Caught On Tape… and Fixed!: I love this — it’s a video collection of 18 AI bugs captured from various games with a discussion of why they happen.
For example, from Half-Life 2:
A player is carrying a barrel in front of his eyes such that it hides all enemy NPCs in the scene. This in turn causes the enemies to not attack until the player drops the barrel!
[…] the sensory system in Half-Life is built to help prevent player frustration, so that soldiers and enemies in the game do not attack the player until the player has noticed them.
In this case, you can use that to your advantage by carrying a barrel, but you could also demonstrate this bug by walking backwards into a room full of enemies!
It’s an interesting look at how AI in games works, and some of the compromises that have to be made.
If you’re interested in this, note that this is from a site called “aigamedev.com” — it’s all about AI in video games.