Game development demands constant testing.
Even though the authoring tools and workflows are designed to give you previews of your levels and content that are as accurate as possible, there is no substitute for the real thing. Not only do you have to test all the content you are working hard at creating -- models, animations, lighting, level design, AI, user interfaces, audio -- to make sure that they are working the way you want. Not only do you have to make sure that all of these subsystems behave together in conjunction as you expect. You also have to keep a close eye on your memory usage, performance, and frame rate.
The topics in this section provide details about the various ways that you can playtest your game and get information about what is happening under the hood at runtime.