Some times it happens that we forget keys of a lock or lose the keys. Then we have to wait for someone to bring us a key or we break the lock to unlock it. Is there any trick or can we develop some kind of master key to unlock without breaking the lock?
Have a spare key for any important lock you have. When it comes to front doors, some people have a spare key given to their trusted neighbour in case of the situation you described, others have it hidden somewhere around the place.
A professional, licensed locksmith will be able to open most front door locks without the key. If you have the time and inclination, you can also learn do this yourself. This is called lockpicking—and when you aren’t doing it to your own property, or doing it as a licensed locksmith, it is illegal just about everywhere in the world.
If you want to do it yourself, you will need tools that may be difficult, or even illegal, to obtain. And because picking a lock looks like breaking into a house, you may draw the attention of police (or neighbors who might call the police), at which point you will have to explain that this is your property, and then hope that the officer believes you, understands the law, and that you actually are using the lockpicking tools legally. Otherwise you might need a lawyer. How large a risk this is depends a lot on your neighborhood and jurisdiction, though. Plenty of people do practice lockpicking as a hobby (there are YouTube videos on it).
If you're locked on the other side, look for a tiny hole on the doorknob. Push an eyeglasses screwdriver, a paper clip hammered flat, or a very small butter knife into this hole. Push it straight through as far as you can, and turn or twist it until it catches a groove and the lock clicks open. Pick the lock. just slide the card into the crack in the door, right where the lock is. Tilt the card so the side that's closest to you is almost or is touching the doorknob. Push it until you feel it slide in more. Bend the card the opposite way, forcing the lock to go back.
- Standard Instructions for Opening a Combination Lock 1.Turn right three times. Stop at First Digit. 2.Turn left one full turn passing 1st number and stop at Second Digit. 3.Turn right and stop at Third Digit. Pull shackle. Profit.