To learn how a state machine works exactly and how to code one in Godot (non-beginner level), check out our guide on the GDQuest website: www.gdquest.com/tutorial/godot/design-patterns/finite-state-machine/

I think that state machines makes everything easier the more states the player has. If I just code a character that can be idle, run and jump the state machine can be unnecessary. But when more states are added the state machine helps a lot.

There's nothing about the state machine pattern that says you need to split things into multiple files and nodes. The pattern is about having a set finite states a system can be in. At it's most basic, one state at one time. So you could still have a bare bones implementation of a FSM in a single file with no boilerplate. Example: a switch statement that checks a string of the current state

There comes a point in your Character Controller, no matter the gameplay or 2D,3D variations where a State Machine is pretty much mandatory. That point gets closed in by adding features. The more different things your Character needs to do, the more you should invest in a State Machine, best case is you have Design Doc ready for you and really, reaaaaally think about this beforehand, what your Character needs so you know before hand if you have to implement a state machine or not but here are some pointers: State Machine make things like Jump Buffers and Coyote Timers, Separate Air and Ground Attacks, Combo Strings and all the stuff that is more advanced than 99% of all youtube game dev tutorials out there (because usually the creator lacks the skills to implement these themselves), fairly trivial to progress and debug. If you want to make anything more advanced than Megaman or Mario Bros., for example Megaman X or Super Mario, a State Machine is pretty much a must, for your own sanity. Don't think of it as extra lines of code but rather time saved having to debug it later on (and ease of use but the debugging alone would be enough) You can easily tell if you need a State Machine if you ever look at your code and think to yourself "Damn, I gotta add another Boolean for this Attack... AND THEN ANOTHER ONE FOR SLIDING..."

Thank you for the video. I was just yesterday trying an FSM for a character, and it does complicate things for me to have to gather references from everywhere for it to work properly. What I would suggest from my experience is to start with the simplest method and then, as the need for using a different one increases, start rearranging your code.

Those two projects look great! Part of some new courses? I love GDQuest courses!

When I started with programming a 2D Platformer, I used to have all the movement in a single script. It was functional, but buggy and I couldn't really expand it. Using a state machine helped me separate a good flow on when I want to send the character to a certain state, that allows specific type of movements.

Thanks sir for the video. 😀🙌🏻 This video is really helpful for the beginners like me even though I'm learning unity for game development .

I'm not really a game programmer. I hobby at it, but I really like state machines. The thing I take with me from my day job is unit testing and making thing generic. It becomes a lot easier to add testing to a smaller script. I think I was jarred in my earlier programming experience. I was working on a MFC program and my one class was over 10k lines. They didn't know about inheritance. Ever since then, I've always tried for short classes that can be reusable and generic. For instance, you have a move class. The goblin and the knight can use the same class. You just have to pass in the animation. As long as you make it generic, you'll be all set. Then, you have one test case that handles all of the characters. One code (ring) to control them all. :) I'll have to watch your other video. I haven't really looked at that. I like what you have and it is very interesting.

Great insights on state machines in Godot

In 3D at least, I think state machines for animation make a lot of sense. It's the defacto Animation method in Godot, Unity, and Unreal for a reason. But the more states you need for AI, the greater the overhead and the difficulty of maintenance, which is what planning AIs alleviate. Planning based AIs have a lot more complexity and over-time performance qualms though.

I find that FSM makes the code more readable to me, so long as the object is complex enough to warrant it, such as the player in my project who has a bunch of different states (idle, move, jump, spin jump, block, melee attack). Enemies, on the other hand, are simple enough that I don't see any reason to use FSM. As for bosses, I want to learn the approach Pigdev suggested in one of his videos. That is, to use the AnimationTree node to more easily create a complex state machine. I am still a beginner, of course, so everything I say might change in a week.

have you released the project for this already so i can cop- i mean, borrow it lol

While I understand it's not so, this video kinda made it seem like the main difference between the approaches is one-big-file vs. many-small-files which is not at all the main difference. How to split code in files is usually just a convention not a hard rule (unless this specific language/engine enforces such a convention). I'm sure you could in principle put all the states in one file, and split the non-FSM code into multiple files as well (though, that might be slightly harder if it's all very interconnected). I must say I never really understood the advantage of state machines when I was taught it in university or even the big difference compared to equivalent code that is not a state machine (beyond surface level details such as how you organise code). Also they seemed to grow incomprehensibly large very fast. The state machine for two buttons is easy enough (but any controller for just two buttons would usually also be pretty easy), but with just a handful of inputs the state graph becomes gigantic network pretty fast; sure that complexity is there in any simple iterative or event based approach too, but with state machines all that complexity is reflected in huge amounts of code a little for every possible state, isn't it?

I don't like FSM because you'll nearly always end up having to be into multiple states at once (running and attacking for example). There are workarounds but it becomes messy quickly. I prefer the second method but I would still split things up by separating them in Components or Layers that live in a list and are applied sequentially every frame. Then you can have many of those "Layers" active or disabled and use composition to create the behavior you want.

what's a general best practices strategy for syncing state machine state in a server-centric multiplayer game?

uhh i wish i could see the full code for the 2D one shown here. i always struggled hardcore with the animation implementation in a FSM :(

So what about the state machine that uses animations? is that node useful too? Also one fear I always have when making a long long script is doing physics stuff, because I always think EVERYTHING related to physics must go inside the _physics_process func, but that is not the case it's just for syncing everything better, so I never know what to do in those cases.

Thanks❤ Please tell us about the factory pattern in Godot) How to use it to create a player, enemies, how to passed the dependencies necessary for these objects

I noticed that States are nested under what looking like a parent State, how is that handled? are those states acting like a sub-StateManager? for example you have a Movement state with Ground, Air and Ladder States under it. Im not sure I understand how this works.

Finite state machines are more flexible. That is almost always a major benefit.

Yes, I have questions big time - I have a 70% completed 3d game in a different game engine (much older) done in javascript (1,000 lines of code) and thinking of using a better game engine with more features like Godot. I dont wish to split my code up into chunks but rather keep it as one whole. Is it better to use Godot javascript or Gdscript and can this be done without too much trouble ? Seesm from this video you can do just that and do you have a template example I can see how to setup this ?

What demo/course is the 2d example from?

Would this work for a 2d top down game in godot v4.0?

Public service announcement: For anyone watching this, I would recommend ignoring this video entirely, there are so many layers if misunderstanding, the vid doesn't capture the fundamentals of what a state machine is, godot doesn't implement actual finite state machines, what they are and their benefits/tradeoffs are not mentioned.

What demo/course is the 2D example in your video from?

To me FSMs are a no brainer. I even use it to control UI. You just need to know how to use it properly.

in the video, state-machine has a weird icon... is it node or it came from script? May I know what it is..

That example of not using a state machine is still using a state machine, just a terribly implemented one. A huge if/then statement with dozens of clauses inspecting dozens of different variables is a nightmare to understand, and horrific to debug, plus as things become more complicated, the gigantic if/then just keeps growing, and then people fall into the sunk cost fallacy, so it never gets replaced with something more undertstandable. PLUS the logic is exactly the same, just worse. Another benefit is being able to use the same state for different characters if you write things correctly. It's easier to have two characters with slightly different lists of behaviors using a bunch of classes, rather than writing out big if/then statements in both of them. While using an if/then statement may save you time initially, it will eventually become a maintenance nightmare. I know this from a lot of experience. I worked at a game company for a week where the lead dev had written a gigantic if/then statement with probably 50-60 clauses that each looked at variables scattered throughout the code in random places. I quit quickly because the idea of staring at that mess of spaghetti every day made me want to cry.

I just don't know if I should do my state machines all in code or if I should use the animationnodestatemachine I like the node one but am struggling to get it to do exactly what I want what would you guys recommend ?

I made an abomimation that is a blob code with stat machine because the animations are state but the player code is a blob