FRONT DESK AGENTS CAN ALSO BE AGENTS OF KARMA. - Hotel Secrets from Behind the Front Desk
Any arriving guest should receive what are referred to as initial keys, which are programmed to reset the door lock when they are first inserted, deactivating all previous keys. Not until the keys expire or a new initial key enters the lock will the keys fail to work. With a "key bomb," I cut one single initial key and then start over and cut a second initial key. Either one of them will work when you get to the room, and as long as you keep using the very first key you slipped in, all will be well.
But chances are you'll pop in the second key at some point, and then the first key you used will be considered invalid. Trace that back to me? Not a chance. Trace that back to the fact that you told your 9-year-old daughter to shut her mouth while harshly ripping off her tiny backpack at check-in? Never.