I am using a state machine in my game. I have 3 states so far: Idle, Walk, and Run. Am I over utilizing the state machine when I could just combine it all into one or is this fine?

A state machine is just a way to roll a bunch of program actions into one change. When you go from state A to state B, you can be sure that x, y, and z will happen. It has the added benefit of making it easier to be sure that you always go through state B when you're moving from state A to state C, for example -- it lets you plan out how this part of your game will run without having to track every change involved.

Using state machines is like using object oriented code -- a lot of people find it helpful, but you may or may not, depending on what you're doing, how you're doing it, and how you're used to doing things. I'd advise every programmer to learn how to implement state machines, but it's hard to tell you if and how you should use them without knowing everything about your project (and your programming style).

InTheProcess What I do is usually drop my states each into their own function. This makes code easy to read and also very easy to hunt bugs. In my horror game I am working on, my walk, run and idle states are all their own function and then I use a separate function to determine which should be working. You could use a match statement here, an input function, what ever.

    If you want another example, my big rogue-like project uses classes for states. Every time I change game state, a lot of code gets executed.