Chams are built to take falls, in fact, they use falling as a defence, I call it,
the 'suicide drop'!

When they feel a threat, they simply fall from where ever they are to escape.
All of my guyz have fallen several times w/o and injury.
But falling on a really hard surface, from more then a few feet, would concern
me.
If you have a Reptibreeze type cage, they have a somewhat thin and flexible
plastic floor that 'gives' a little if they fall on it.
Even my big guy, Smeagol, falls sometimes and I can hear the 'thud' clear
in another room.
He is never hurt though, just has a "surprised" look on his face as he lays
there on the floor, all 4 legs spread out!!
It takes them a few seconds to get their bearings and get up.