Today, developers have a huge variety of ways to create and manage enemy AI. However, back in the '90s it was much more difficult to create sophisticated enemy AI. It was even harder to do so on the N64 due to its limited power and resources.
But Rare, the developers behind GoldenEye, pulled it off. In fact, they did such a great job that, after playing GoldenEye, developers at Valve actually changed the then-unreleased Half-Life and its AI.
The wonderful YouTube channel AI & Games recently uploaded a new video covering how the AI enemies and NPCs in GoldenEye actually work, and how Rare was able to create enemies that felt smart and complex on limited N64 hardware.
One of the ways Rare was able to create such impressive AI was by building the entire game around the AI enemies. This allowed players to actually see and interact with the AI. As Martin Hollis, the producer and director on the game, explained in 2004, “The important thing is to show the player the AI. There’s no point having sophisticated AI that the player doesn’t notice.”
This meant every level and gameplay mechanic was built around the AI, making sure players were constantly encountering and dealing with the enemies and NPCs that populated the various levels.
Another developer on the game, David Doak, later explained in an interview that he met the folks from Valve at a 1998 video game trade show in the UK. They told Doak that, after playing GoldenEye, they felt forced to “redo a bunch of stuff on Half-Life”.
This is most likely a reference to GoldenEye’s AI systems. Half-Life employs a similar system for its baddies and NPCs.
The entire video is a really great deep dive into how a classic video game works and how difficult it was to make smart AI back in the day.