You've seen the signs -- they're often found in small, high-end retail establishments. They warn parents with small children and instill fear in the clumsy. They make you want to put down the merchandise and slowly back away.
But are these policies enforceable? Is there some sort of "You Break It, You Buy It" law?
No -- and yes.
A store cannot hold you hostage until you pay for an item you break -- that's called false imprisonment. And you can't be arrested for accidentally breaking merchandise -- it's not a crime.
But, if a shopkeeper really wants to make you pay, he can take you to court. A judge may then order you to pay for the item if (a) the sign is found to be a contract, or (b) you were negligent.
Luckily, the contract argument is quite weak. The shopkeeper needs to prove that you saw the "You Break It, You Buy It" sign and that you agreed to its terms. This is nearly impossible to prove, which means very few courts -- if any -- will accept this theory. (There are other potential issues here as well, such as a lack of consideration.)
However, a court is more likely to accept a claim based on negligence. Customers have a legal duty to exercise due care. People need to act with reasonable caution and vigilance when in a retail establishment. If a running child or a swinging purse ends in broken merchandise, "You Break It, You Buy It" may legally apply.
But if you were careful, you probably won't have to pay. Especially if you fell prey to small aisles, crowded floors, or improperly shelved merchandise.
So while there is no official "You Break It, You Buy It" law, you still don't have the right to act like a bull in a china shop. If you do, you may end up buying a broken lamp.
Editor's Note, November 11, 2014: This post was updated to clarify the element of consideration in contract law.