Why use Tri after done game modelling?

#1

Why do people use Tri instead of Quad after finishing modelling for games?
Do you have to use Tri instead of Quad for game modelling?

#2

Game engines can only actually display triangles. Most will automatically triangulate for you when you import a mesh, but if it triangulates differently than you want, there’s no way to fix it. As such, it’s better to triangulate in Max/Maya, so you can go in and fix any issues that might arise.