Lock

Locks are found throughout the wasteland on doors, safes or boxes, usually barring access to all kinds of rare or common items. The player can use his/her Lockpick skill to pick the lock with bobby pins. Some can also be unlocked with keys.

Lock difficulties
Locks come in 5 difficulties: very easy, easy, average, hard and very hard. Which locks you can pick depends on your Lockpick skill (see table to the right). Difficulty and your Lockpick skill also determine the probability of success for an attempt to force a lock open (see Forcing a lock open below).

Experience points
Depending on its difficulty, successfully opening a lock grants an amount of XP. Lockpicking very easy locks yields 10 XP whereas bypassing a very hard one results in 60 XP (without any XP reward-increasing perks). Easy, average and hard locks are worth 20, 25 and 50 XP respectively.

Picking a lock
In Fallout 3, picking a lock on a door or container takes the form of a mini game. In order to pick a lock, you must have a skill high enough for the difficulty of the lock, and you must possess one or more bobby pins. Bobby pins are weightless items, often found in first aid kits and locked containers. In the mini game, you insert a bobby pin and a screwdriver (a free, weightless item which does not appear in your inventory) into the keyhole of the lock, rotating the pin to trip the tumblers in the lock, and the screwdriver to turn the lock, in place of a key. If you try to open the lock with the screwdriver while the bobby pin is in the wrong position you might snap the pin, requiring you to try again with a new one.

A point of interest. The way in which lock picking is portrayed in Fallout 3 is almost completely inaccurate. True, a tension wrench (screwdriver) and a pick(BobbyPin) are present, but the action of actually picking the lock is nothing like what a pin tumbler lock or most other locks with a cylindrical design would require to successfully manipulate the lock.

Strategies for PC
First, there is the bobby pin. You can wiggle it from left, over the top, to the right. Choose a random position. Now, tap A gently, and release it. The pin could wiggle. In that case, move it to another position. If the pin did not wiggle, press A a little longer each time. You don't need the W, S or D. (But you can use any of the four keys. They do the same thing.) If the bobby pin starts to wiggle, the position is wrong. Choose another position. Repeat till success.

If you don't want to break your bobby pin, stop touching A as soon as the bobby pin starts moving: just put it somewhere else, and try again.

A few notes:
 * 1) Don't move the bobby pin while moving the screwdriver. The point is simply to have the bobby pin in the right place when the screwdriver reaches it. If the pin wiggles (instead of the lock coming open), the pin is in the wrong place, so release the screwdriver immediately. (That's all there is to it, ultimately! Read on.)
 * 2) As has been said, you only need to use the A key, despite the game directions.
 * 3) A lock that is Very Easy may (or may not, depending on your skill) open simply by moving the screwdriver while leaving the bobby pin straight up. The difficulty level defines how "close" the bobby pin needs to be along the arc of the lock (the upper half of a circle), and Very Easy may be wide enough for the whole arc, depending on your skill.
 * 4) The screwdriver moves faster if your pin is closer to the right position; conversely, the pin starts wiggling immediately if you are far from the right position - and it's time to try some other position. So, always be ready to immediately release the screwdriver as soon as you get any resistance (wiggling) on the bobby pin.
 * 5) The magic number for lockpicking is "3". Even if you are very sensitive about stopping pushing the screwdriver when the pin wiggles, your bobby pin will most probably break on your third unsuccessful attempt (though if you are REALLY sensitive, you can make as much as seven attempts before the pin breaks), so if you are running low on bobby pins, just quit and retry after the second time, restoring your pin to its full "strength"; similar to attempting to hack after too many unsuccesful attempts save one. The lock may also change the position the pin needs to be in when retrying the same lock.

Strategies for Xbox 360 and PlayStation 3
The position of the bobby pin is controlled with one stick and the screwdriver with the other. The controller will vibrate with the wiggling of the bobby pin and vibrate strongly as it starts to break. As you find a position nearer the sweet spot, you will be able to rotate the screwdriver a little further until you are successful. As soon as you feel the pin is starting to break, move it then try again. If it starts breaking again on the third turn, exit out of the lock and then re-enter to try again. If done correctly and patiently, all locks can be picked without ever breaking a bobby pin (which can be hard to find). The same principle applies to hacking computers.

Forcing a lock open
It is also possible to skip the mini game by attempting to force the lock open. The probability of success for this action depends on your Lockpick skill and the difficulty of the lock. The only combination which has a 100% success rate is a very easy lock at a Lockpick skill of 90-100, every other combination will have a smaller percentage.

If you fail at forcing the lock open, it will break and no other attempt at opening it can be made unless you have the Infiltrator perk (which grants a second attempt).

Bugs
Tested on a few occasions (Xbox 360), once your bobby pin breaks if you immediatly press the "Force Lock" key the lock will be picked. The screwdriver continues moving with out a pin hitting any tumblers.