Saw
46 Achievements
1,000
8-10h
Professional
Unlock 20 locked doors.
50
How to unlock the Professional achievement in Saw - Definitive Guide
Watch out for trap in the main room!
You should be able to get this through playing the game, but if you still need to find a few doors, there's a method similar to getting the Stomp trophy:
-Play through Amanda's level until you get to the first door to unlock. Once you've unlocked it, continue through the level until you get to a checkpoint. After the game saves, reload Amanda 1-4, and unlock the door again. Continue to the checkpoint, and repeat until you get the trophy.
To pick a lock you will need a nail. The first one can be found inside a nurse cart inside the left-hand room after using the key you get from searching the first NPC you fight. You use up the nail when you successfully pick a lock, so keep searching desks, cabinets, etc for more during the game.
When attempting the lockpick, you need to match up the ends of each small gear to the gear on either side. So if you have a gear with a screw on the left and a red button on the right, rotate the gears on either side to match. Obviously if a gear on either side can't match up, you'll have to rotate the starting gear and work from there. Once you figure it out once it is a breeze from then on.