A good question about TDD with game development.

Really it depends what you mean by game development. If we are talking about creating a game engine then TDD absolutely has a place in the development process. It can be used like it is in any other application where you write tests using whatever framework is appropriate to express the business logic in logical chunks (individual tests that test a single requirement, not multiple requirements at once, this makes it easier to troubleshoot when a test fails). As far as I know a game engine is not much different from any other software so following TDD principles should be no different.

If however we are just talking about creating a game from an existing engine then things might be a bit tricky. A quick search shows that Unreal Engine supports some form of testing but I am not sure how easy to use it is. Another issue with writing tests for games is how can you express the logic of the game in a test? Sure, you can test things like the math or physics libraries, but what about more complex functionality? Overall I don’t think it would be worth trying to test games given the large amount of possible use cases, it would likely be too much of an effort to test the game as a whole. That however does not mean you should not test individual libraries/modules!

I am curious to know what developers who actually do game development use for doing their tests and what exactly they try to test when it comes to game functionality.