1.) Which is the best form of AI to start of with? Besides basic AI, found in small platform games like Mario... 2.) Which type of AI is usually used in a FPS game? Not too advance, like Halo :p Sorry I haven't provided more detail, but these questions aren't overally complicated, lol Thanks :)

You should look into A* (a path finding algorithm), For many games, a good portion is about picking where to go; with A* just telling the bot how to get there. For example: You have a bot and a player, the bot wants to protect point A. The bot 'sees' Point B, a rock, Point C, an open place, and Point D, a tree with good concealment and a nice view of Point A. You can use A* to get to any of the points. But your AI should figure out which point to go to. I would say Point D, but you want to know how a bot might do this? For an FPS, I would say a Finite-State machine which decides if its attacking/defending etc. And each state has a specialized (read: trained) neural net for picking points for that specific task of defending/attacking. The rest of the AI such as aiming, is either straight forward math, or extra goodies (squad like behavior).

Thanks :)

I was thinking A*, but was unsure...