Ladders, Crates and Toilets in Video Games…

Ladders:
Going Up = no problems.
Going Down = fall and break legs or die

Crates:
Conveniently located for cover from enemy fire or for getting to higher ground,
or
Melee smash giant crate until it explodes and splinters into a handful of toothpicks - the only thing inside was some pistol ammo and 2 AA batteries.

Toilets:
Walk up to toilet + press action button