boring-game theory

 An elevator in my game uses unseen pulleys.

A lever controls how the weights on the unseen pulleys counter the weight of the elevator.
People point to this stuff a little proudly, I think, to explain complicated math problems they know or at least can put onto a paper.

My boring-question was,
"Yes, a pulley (wheel + rope) works, but what about multiple pulleys?"

Wait, I'll come back.
In theory, everything works exactly like mathematicians say, but *I* would worry about your head being bonked by falling pulleys tilting left-right slightly and disentangling themselves. 

This next pic is more obvious on how stuff could go horribly wrong, or is that just in my head?

No one cares about pulleys; they're really trying to show-off their math prowess.

But I worry about slack and side-to-side wiggling and falling.

Forgetting math completely, 

do the pulleys (those little wheels) have to move or can they be nailed down, so all you have to worry about is the rope?

I'm reminded of a self-threading 16mm projector, with all its gears.

But then I'd have to explain projectors and 16mm, and the schools using them...
I'd better stick to pulleys.
I'm guessing that despite it being easier to move something, the total brunt of the weight is supported by *something* which had better not bend or break.
Three two-by-fours in my head, the middle one straddling the other two (like in a doorway) might cause it to snap in two if you dared to use a pulley on it (to move stuff between floors?)

Pulleys are not practical without a few more inventions to accompany them...