Create 3D Computer Games

Want to create your very own 3D computer game? Just don't know where to start? Read on and find out how!

Steps

Know that making a simple 2D game such as Tetris is much more difficult than it looks. Creating a 3D game is even harder. You have to take many things into consideration. Games such as the classic Pac-Man and Snake are also harder than they look.
Choose one of the several different programming languages. There is no "best" one, and each has its own ways. You can choose from C++, C#, Java, Python, and many others. There are many tutorials out there that you can find using a search engine such as Google.
Start out small, very small. Get used to the syntax of programming languages and slowly move on. After all, you must learn to crawl before you learn to walk. Then, you must learn to walk to learn to run.
Work to become proficient in a programming language. Make sure you can create a window, use Object Oriented Programming and make somewhat complex mathematical calculations.
Choose an API (Application Programming Interface). Some examples of API's are DirectX and OpenGL. There is one thing you have to keep in mind, however. Some API's are limited only to certain Operating Systems. For example, DirectX is limited to Microsoft Windows, while OpenGL is not.
Try 2D applications first. Once you can create a simple Tetris or Breakout clone, you are ready to begin.
Look at the documentation for the API you are using. This has lots of information on how to use the API.
Use an existing engine such as Source, Unreal or Unity 3D. Use this method if you are finding it difficult.

Nobody can say "You can't".
Start out small and work your way up to more complex creations.
HAVE FUN
Don't be afraid if the syntax of a programming/scripting language hurts your brain at first.
If you are going to publish your computer game, create the game from scratch. This way, you can't get sued for using someone else's work or program.

Always back up your work if it is a big project, or face the possibility of losing everything you have done.
Do not, under any circumstances (unless it's extremely private, i.e. you are the only one that has access to it), use something that is not your work in your applications. That is called copyright infringement or plagiarism and may get you into severe legal issues (e.g being sued).