Why shouldn't you change a RigidBody's velocity directly?

I keep seeing people say “don’t change velocity directly, do AddForce/whatever instead”. The official docs suggest that you shouldn’t because it results in unrealistic physics. This is precisely what I want, I don’t want realistic physics…is this ok? Are there any actual glitches that I would run into by setting the velocity directly? Thanks.

Just make sure your changes of the velocity are made into FixedUpdate and not Update, so they are happening as often as the physic loop, and you should be ok.