Caesar Cipher by Matt Crypto from wikimediacommons.com. Public Domain
This code is similar to the code ROT13.
I like this code because it is rather simple, and it is fun to decode. If you want to make your own decoder, you can go to this website to learn how. I also like that it's versatile. You can change the shift to however many letters you want, and it is still easy enough to decode! It's nice and simple, and a good code for beginners, though it is a bit more difficult than ROT13.
Practice it here!