The rule is simple. ANYTHING THAT GIVES AN UNFAIR ADVANTAGE!
This means regardless of how easy it is. If you have to ask, dont fking do it.
Breaking unbreakable things, moving through walls, xraying in any form, flight glitches, anything and everything else that you have to go out of your way to make purposfully to break a childrens game mechanics.
So shut up and play, or leave. Quit being a pansy, looking for ways to cheat the system.