What are limitations of a back player in volleyball?

Answer 1

if they want to hit, they can't jump after they have crossed the attack line, but they can approach and everything as long as they are behind it. They also can't be in front of a front row player before the ball is served. And all the basic rules about rotation and so forth.

Answer 2

You can't spike a ball, unless its a back row spike, and you can't go in the front. those are pretty much the only restrictions.