Skyrim:Lockpicking

Lockpicking is a skill that allows you to access most locked rooms and containers, or to disarm certain traps, without their corresponding keys. The Lockpicking skill tree has a total of 11 perks, requiring a total of 11 perk points to fill.

In-game Description: The art of lockpicking is used to open locked doors and containers faster and with fewer broken lockpicks.    
Skill Perks
 
 
 

 
 

Skill Usage
When you target a lock/trap that you don't have the key for, but that can be picked, a tooltip bubble ("Unlock (object or location)") will indicate its difficulty level on a scale from "Novice" to "Master". If you have at least one lockpick in your inventory, interacting with your target will activate the lockpicking interface. The lockpicking interface shows a dagger for turning the lock, and a lockpick for disarming the locking mechanism. Your objective is to place the lockpick on the correct position in a 180 degree arc. Only then can you fully turn the lock to open it. Trying to turn the lock with the lockpick in an incorrect position will result in the lock refusing to open and in permanent damage to your lockpick.

Picking the lock successfully requires a certain degree of trial and error. Successful strategies to reduce the number of lockpicks broken may make use of the following facts:
There is a tolerance zone around the correct position for the lockpick. Within this tolerance zone, the lock may budge a little when turned; the closer you are to the correct position, the more the lock will allow itself to be turned.
The more force you exert on the lock when the pick is not in the correct position (i.e., the longer you press the key to turn it), the more damage you cause to the lockpick. Initially, only tap the "turn-lock" key to minimize damage. As you hone in on the tolerance zone, you can afford to use gradually more force.
Make a note of the lockpick position before you start turning the lock, as when the lockpick breaks, the new one will (normally, see perks) be inserted at the initial vertical position. Use irregularities in the texture of the lockpicking interface to help you; the further away from the center of the lock you pick your reference point, the better you can see and aim the lockpick.
Beyond the very visible shaking effect when you strain the lockpick, users report audible cues when slowly sliding the lockpick across its range. Irregularities in the grating sound or distinct clicks may give away the correct position.

The challenge of the lock is inversely related to the size of the tolerance zone. A larger zone makes it easier to find and allows more leeway before the pick breaks. The size of the tolerance zone is increased by your lockpicking skill and any active bonuses (granted by perks, suitably enchanted gear or potions). It is decreased by the difficulty rating of the lock. It is therefore possible to pick a "Master" level lock with a low lockpicking skill, but you will probably break more lockpicks to get it open.

Skill Increases
Experience is given when you successfully pick a lock for the first time and when you break a lockpick. If you break a lockpick, a small amount of experience is given, enhanced by the Thief Stone and other XP bonus. If you successfully pick the lock, the experience gained is based on the difficulty of the lock (harder locks give more XP) and whether you have the Thief Stone activated.

Leveling lockpicking "on the go" is perfectly viable. If you wish to speed up your advancement in lockpicking at the expense of a little time, you can refrain from looting/pickpocketing most keys and pick their locks instead, with little to no impact on the rest of the game.

Should you wish to power-level lockpicking (e.g., to quickly gain access to specific perks in its skill tree), you can intentionally and repeatedly break your lockpick in a lock. For this tactic, a lock that does not open on the default, vertical position is preferred, and requires either a large amount of lockpicks in your inventory, or the Skeleton Key which is obtained at a late stage in the Thieves Guild storyline and does not break (but failed attempts still count for the purpose of gaining experience). As a note, be sure to be well-rested and have the Thief Stone activated.

Character Creation
The following races have an initial skill bonus to Lockpicking:
+10 bonus: Argonian
+5 bonus: Bosmer, Khajiit

Trainers
Ma'jhad with the Khajiit Caravans (Expert)
Vex of the Thieves Guild in Riften (Master)

Skill Books
Advances in Lockpicking
Proper Lock Design
Surfeit of Thieves
The Locked Room
The Wolf Queen, v1

Free Skill Boosts
+1 Lockpicking reward (as well as +1 Light Armor) from Shahvee (Windhelm) for completing the quest Find Shahvee's Amulet of Zenithar inside  .
+1 Lockpicking reward (as well as +1 to all other stealth skills) from Inge Six Fingers (Bards College) for completing the quest Finn's Lute.
+5 Lockpicking reward (as well as +5 to all other stealth skills) by selecting "The Path of Shadow" from the Oghma Infinium after completing the quest Discerning the Transmundane.

Achievements
One achievement is related to Lockpicking:
 

Notes
Alternative ways to open locks:
You can ask a follower to open a lock for you, which they will always succeed at if they're willing to try, even if the 'lock difficulty' is extremely high. If they are detected, the crime will be attributed to you.
Some locks have keys that can be pickpocketed or looted off related NPCs (bosses, shopowners, etc.).
The Tower Stone confers the ability to open any pickable lock (except master-level locks), once per day.
You can save before attempting to pick a particularly challenging lock to limit your loss of lockpicks; however note that you will have to start over again on reload as the opening position will be randomized anew.
Opening up the lockpicking interface and attempting to pick a lock are not crimes, just as activating the pickpocket command without taking anything is not a crime. Successfully lockpicking a door or chest owned by someone else does constitute a crime, so if you do so and it is witnessed, you will incur a bounty (unless you have the Quick Hands perk). If you're trying to pick a lock unnoticed, you can get into sneak position so you can determine if anyone can see you. If you activate an owned lock while detected, and then break a lockpick, the lockpicking window will close, you will acquire a 5 gold bounty, the lock will reset, and you will have to try again.
In the Thieves Guild Headquarters, you can find a training room that contains a series of locked chests of different difficulty level. While all but the novice-level one will reset, they are subject to the same restrictions as other chests and your Lockpicking skill will not increase by re-picking them except for the small amount gained through any broken lockpicks.
Pressing both the left and right hand attack buttons simultaneously will result in the lock rotating faster. This is useful if the player is confident in picking the current lock, or if the player has obtained the Unbreakable perk.
All the locks more difficult than Novice have a 4% chance of being 10% easier. Then, each tier is 2x as difficult as the last, whereas Master Locks have a 1.875° spot as their base sweetspot. Your Lockpicking skill multiplies that by 1+0.6% per point, while the perks like "Master Lockpicking" triple this, multiplicatively. Then, additively to each other, come potion effects and enchantments, though Seeker of Shadows  is likely multiplicative again.
As it is currently understood, the formula for determining the size of the lock's sweetspot can be expressed like this:
 

Bugs