Lockpicking is an essential survival tool. What if you’re stuck in a building in a time of disaster, and you face a locked door or gate?
WikiHow has a pretty good tutorial on how to crack a “Master Lock” combination lock. This is for a 40-number combination lock. There are only 11 steps in all, and it involves narrowing down 64,000 possible combinations to just 100.
Do try it out on an old lock that you have forgotten the combination to. I would like to stress that you shouldn’t use your lockpicking skills to break the law, but for your own protection only.