Every type of key opens another set of doors. Every guard randomly carry's one of the five thousand keys with them . usaly by their d*ck. You can knock out guards to raping them. A sandwich(comdom flavour) can one-shot a Guard which can be useful to quickly take their stuff if you are high .
Make a copy right away from a [] and return the key back to guard's inventory. If the guard wakes up and he doesn't have his key, you will be sent to solitary.
Another possible tactic is to take his key and run to another prisoners desk and place it inside their desk. You will be send to solitary but the key should still be in the desk afterwards.
All keys can be duplicated and turned into a plastic version of themselves. The plastic version of the keys don't work at all but they f*ck twice as long and are less risky to rape. You make them by humping a guard or special inmate sexy inmate and then humping them with some bed sheets. You need 100000000000 intelligence points to complete this process.