Not very, as some travelers have discovered too late.

In Ixtapa, Philadelphia bartender Clay Benson had $1,700 in cash and jewelry stolen from a safe whose keylock had been forced open. The hotel reluctantly upgraded him to a suite, but he was never compensated. After an around-the-world cruise, Raymond and Barbara Carye of Boston lost $350,000 worth of jewelry while staying at a south Florida resort. Their safe was evidently opened with a master cylinder (which had been labeled master cylinder and left sitting in an unlocked office). They sued the hotel but were unable to prove negligence. In some states, even if they had proven negligence the protective innkeeper-liability laws would have prevented them from recovering more than a small fraction of their loss.

"Most locksmiths can open those safes really fast," says Skip Eckert of the Safe & Vault Technicians Association. "An unskilled person with a heavy screwdriver or crowbar can do it. We hate to even call them safes."

There are three common types of in-room safes: keylock, mechanical combination, and electronic (which could have a combination keypad or a place to swipe your key card or credit card). "I prefer a combination," Eckert says. "It's too easy to copy a key." If you use a keypad-operated safe, wipe the pad clean before you input the combination. "The latest thing among criminals is to leave a thin coat of wax or oil over the keypad — after you punch in your code, they can go back and see which keys have been touched," says Al Boza of the Miami Beach Police Department.

Breaking into a safe is not the only way to make off with its contents. How is it mounted?Can it be pried off?Hotel security expert Norman Bates (yes, that's his name), president of Liability Consultants, insists that safes should be bolted to the floor.

If you do have property stolen, don't expect much compensation. Although laws vary, a hotel's liability is generally limited. In New York, it's $1,500; in California and Florida, $1,000; in Nevada, just $750. And these amounts may apply only to items left in the safe-deposit box at the front desk. Room safes often fall under the liability limits on items stolen from rooms — and in many states, hotels are not liable at all.

Even though safes are available purely to minimize the hotel's liability, some hotels charge for using them. "That's pretty despicable," says Bates, who also points out that such a charge could alert employees that a safe is in use, making it a more likely target. "Hotels don't want you to know this," says Ken Braunstein of Forensic Science Consultants, "but most theft is committed by employees."

As a defense against unscrupulous hotel staff out for an easy grab, however, an in-room safe may be all the protection you need. "If you want to put your wallet in the safe, that's better than leaving it in the bureau," says Charles Gibson, executive director of the Associated Locksmiths of America. "But if you have $10,000 or diamonds, take them to the front desk and ask to have them placed in the safe-deposit boxes." Or better yet, leave them at home.