Safe-cracking is a way for someone to try to open a safe without using the right combination or key. It requires a lot of knowledge, practice, and skill, but basically someone who can do this is a kind of "safe-hacker". They use special tools and techniques to try to open the safe without using the combination or key. This can be done by feeling the tumblers in the lock or by drilling through the lock. It can also be done by using a stethoscope to listen to the sound the tumblers make when they are being manipulated. Safe-cracking is usually illegal and very dangerous, so unless you’re a professional and have been trained, it’s best not to try it!