wololo.net/talk

So, there are scripting languages (like Lua) and there are languages like C# and C++
With the big games, usually they use an engine which is basically a framework that provides all the main functionality like the model loading, rendering and stuff. Then for things like AI, scripting languages are used, a lot of the time, the interpreter for that language is built into the engine, scripting language is used for AI et al because AI is something that may need a lot of modification, you can't afford to make one small change then rebuild the entire game and test, so instead they use interpreted scripts. This doesn't mean you can't code a game in Lua or you can't code AI in C#/C++, it all depends on your preferences/requirements and your project size, I wouldn't mind having the AI in C# if it were a small project.

In the end it always boils down to what you know, what you want to know and are you motivated to pursue your goal.

hgoel0974 wrote:because AI is something that may need a lot of modification, you can't afford to make one small change then rebuild the entire game and test

Not exactly true. You can always use a separate library and then you just have to compile the library, not the whole game. But yeah, your point is correct: you don't have to rebuild the library for such things, and you can even make these changes when the game is running, or debug it live.

Multiple different languages, it depends on the part of the game, Game Engines suchs as 3D Unity is used for graphics C for organizing, you know timing and telling the console what to do when, you can even use python to make a simple program for shaders. Like m0skit0 said you dont have to compile the whole game to debug, you can just live debug where its runing the code directly and not a compiled app version, after it is ready for release that is when the creators compile an app.