Answer:
I can be cracked, I can be made. I can be told, I can be played.
This is needed both for courage and hardcover books.
Look into my face and I'm everybody. Scratch my back and I'm nobody.
We travel much, yet prisoners are, and close confined to boot. Yet with any horse, we will keep the pace, and will always go on foot.
Always old, sometimes new. Never sad, sometimes blue. Never empty, sometimes full. Never pushes, always pulls.
What gets broken without being hold?