Dual quaternions are relatively new. You don't find them in many computer graphics books and very few people use them. Nonetheless, it is a mathematical concept you should be aware of if you are planning to develop a game engine.
To develop a game engine, I knew I had to learn a lot of math and programming concepts. However, learning how to model a 3D game character was never one of them.
I don't play video games. I don't even own a game console. Yet I'm developing a game engine. Find out why I ended up doing something I wasn't qualified to do.