VFX in games?

Boyani

Even i am doing 3D Modeling atm, i am curious about vfx in games. Mostly i am interest in style like WoW, LoL, Dota 2. 
For doing vfx, what kind of theory do i need to know? I am speaking for math, programming, physic..do i need to know any of this or something or nothing? 
And for style, how to achieve this stylized art in vfx?  And what else do i need to know about vfx in general? What to use? What to learn? Is there a order or something to learn step by step?  

.Wiki

Learn about vector math, trigonometric functions and matrices if you want to write your own shaders. Even if you can use visual editors in some engines you need to know the math to know what you are doing.

PixelMasher

this guys youtube channel is dope. Just dive in and start following what he does, you will learn a lot faster just by doing rather than trying to figure out everything you need to learn. 

https://www.youtube.com/user/vladderbeest