In countries that have implemented the Berne Convention, are contracts protected under copyright?
OK, I misread.
As a non-lawyer, I would guess that it’s a question of how “original” the contract is, just as with any other kind of written document.
Under U.S. copyright law, forms cannot be copyrighted, so a “standardized” contract form would not be copyrightable. Even filled in, contracts contain mostly facts and information, expressed in common legalese.