Today I accidentally dropped my MacBook Pro.
I had it open on a stand on a desk with some headphones plugged into it. I took the headphones off my head, got up out of my chair, caught my foot on the (overly long) headphone cord and, as I walked away, the mac came crashing to the floor, yanked off the desk by the headphone cord.
*crash*
*bang*
So, I picked it up, dusted it off and opened the lid (which had snapped shut during the fall). Much to my surprise, it came right back out of sleep as if nothing had happened. Inspecting the case there was no damage, not even a dent. The only sign of the incident is that now pressing down a specific part of the case makes a slight squeaking noise.
Impressive, most impressive. The aluminum clad MacBook Pro is one tough, sturdy, well-built, resilient, solid piece of computing equipment that knows how to take a punch and keep on going.
As a comparison: I once dropped my old Dell Inspiron 4150 from a similar distance while it was turned off and inside a protective laptop bag (Kensington Saddlebag). It still worked after the crash, but the plastic case was cracked and severely warped, the DVD-drive wouldn't fit anymore and several keys popped out. Dell, to their credit, later repaired the damage under warranty when the motherboard died.
However, if you have a habit of dropping your laptop it's probably a good idea to have an external backup, and for even more security you can protect your files with an online backup. A good place to start for choosing an online backup is to read a few just cloud reviews to get an idea of the services and features typically offered for protecting your files online.
(The hard drive on the MacBook Pros is protected during falls by a sudden motion sensor. There is a gyroscope built into the Mac which detects if it is accelerating too fast for its own good and then, in mid flight, quickly moves the hard drive into a protective "parked" position so it isn't damaged by the inevitable impact.)