Question

It could be part of the model because it’s part of the business logic of the game.

It could be part of the controller because it could be seen as simulating player input, which would be considered part of the controller, right? Or would it?

What about a normal enemy, like a goomba in Mario?

UPDATE: Wow, that’s really not the answer I was expecting. As far as I could tell, A.I. is an internal part of the autonomous game system, hence model. I’m still not convinced.

Answer 1

Remember that MVC was originally purely a GUI architectural pattern. So it is of no surprise that it doesn’t map well to AI, networking, or whatever. But there are still some benefits to using it here. But what the code achieves is not as important as where it sits in the chain. Just because something looks like it’s internal, doesn’t mean that it is, and therefore shouldn’t be counted as such.

eg. If you’re writing a bot, chances are high that you will essentially just be writing scripts to manipulate the characters. So in that sense, the script interface is the pre-existing Controller, and your scripts are completely external to that. You don’t even go anywhere near the Model to write that high level AI..

Now if you were the original programmer, who had to write low level AI functionality, which is triggered off either by player interaction (eg. clicking somewhere to start walking there) or by a bot-style script, then you would have been writing that into the Model.

It may seem unintuitive to have any single concept such as ‘AI’ span all the way from model, through controller, and right out to whoever or whatever manipulates the controller, but that’s how it goes when you attempt to map 2 very different concepts onto each other. It is obvious when you look at it from the perspective of a developer trying to present the same interfaces for non-player characters as they do for player-characters – ultimately the AI has to comprise both the high level decision making that an actor outside of the system would make, in addition to the low level implementation that typically exists for both players and non-players within the system.