Thieving is used to pickpocket GP and items. Each Thieving attempt takes 3 seconds.
Thieving can be done with Offline Progression if the success rate is at 90% or above.
Mechanics
Success Rate
The base success rate of pickpocketing is 57.5%. This is increased by 0.7% for every level in Thieving the player has above the target's level requirement, and is further increased by [math]\frac{1}{400}[/math] or 0.25% per Mastery level the player has for the target. This chance is capped at a maximum of 95%.
Players can go beyond the 95% success rate cap in two ways:
 Thieving Gloves provide +10% success rate as long as they have charges.
 Reaching 99 Mastery means that any pickpocket attempts on that target will be successful.
Two other things may influence the success rate but however will not go above the 95% soft cap, those are:
Although it is possible to see a success rate higher than 100% when using Thieving Gloves, going beyond 100% success rate does not provide any actual benefit.
Loot
 See also Combat#Loot and Rewards
Successfully pickpocketing a target will always award the player with GP up to the Max Coins of the target. There is also a [math]\frac{3}{4}[/math] or 75% chance to receive an item from the target's loot table.
In addition to the rewards for the specific target being pickpocketed, successful attempts also have a chance to reward the player with two rare items in addition to the normal loot:
Bobby's Pocket has a [math]\frac{1}{120}[/math] or 0.83% chance of being received on any successful pickpocket. Although the item itself is useless, it can be sold for 4,000.
Chapeau Noir has a [math]\frac{1}{10,000}[/math] or 0.01% chance of being received on any successful pickpocket. When worn, it provides a [math]\frac{1}{10}[/math] or 10% chance to double loot acquired from Combat or Thieving.
It is possible to receive loot, a Bobby's Pocket, and a Chapeau Noir all from the same action. If the quantity of items received is multiplied due to either a potion or equipment effect, the number of rare items received will also be increased, however the chance to multiply items is only rolled if normal loot is also received from the same action.
Loot can be multiplied in three ways: Gentle Hands Potions can be used to provide a [math]\frac{1}{20}[/math] upto [math]\frac{1}{4}[/math] or 525% chance to double the quantity of items gained on a successful pickpocket. Agility can provide +[math]\frac{1}{20}[/math] or +5% chance to double items gained through the Rock Climb obstacle course. Equipment items can also provide a separate doubling effect (currently, the items/skills that provide a chance to double loot are the Chapeau Noir, Master tier Slayer gear and Aorpheat's Signet Ring). All the bonus mentioned stack additively.
Failure
Failed pickpocket attempts will stun the player for 3 seconds and deal damage to them up to the target's Max Hit; damage dealt this way can be reduced by any damage reduction provided by Equipment. Damage taken while Thieving is potentially lethal, although this damage can be offset by consuming food manually, or automatically with the Auto Eat upgrade.
Mastery Unlocks
Item Mastery Unlocks
Level 
Unlock

1 
Each level provides a slight increase in success rate as well as increased % GP acquired equal to your Mastery Level.

99 
Never fail a pickpocket attempt.

The bonus per mastery level to successfully pickpocket a Thieving target is +[math]\frac{1}{400}[/math] or +0.25%.
Mastery Pool Checkpoints
Pool % 
Pool XP 
Bonus

10% 
400,000 xp 
+5% increased Thieving Mastery XP

25% 
1,000,000 xp 
+10% increased success rate for all NPC

50% 
2,000,000 xp 
+10% chance to receive double items from Thieving

95% 
3,800,000 xp 
+100% increased gold from Thieving

Total Mastery Pool XP

4,000,000

Skillcape
The skillcape can be purchased from the store for 1,000,000 after the player reaches Level 99.
Pet
The pet can be unlocked by doing any Thieving action.
Pet 
Name 
Effect


Snek 
+50% GP From Thieving

Thieving Targets
Profit
Assuming a 95% success chance and that every piece of loot  but not mastery tokens  is sold, it is possible to calculate the average profit over a long time for each target.
This strategy was calculated for v0.16.3 and may have changed in newer updates.

Name

GP/theft

GP/hour

GP/hour with

Man

36.80

44,160.00

48,576.00

Golbin

51.05

61,260.00

67,386.00

Lumberjack

85.11

102,136.13

112,349.74

Farmer

156.21

187,455.11

206,200.63

Fisherman

122.19

146,625.18

161,287.7

Chef

123.85

148,615.81

163,477.39

Miner

124.42

149,309.75

164,240.73

Knight

137.60

165,121.13

181,633.24

Potion
The Gentle Hands Potion gives a chance of receiving double loot while pickpocketing. It can be made with Level 45 using 1 Lemontyle Herb and 2 Strawberry Seeds.
Potion 
Tier 
Charges 
Effect


I 
20 
5% chance for double Thieving rewards


II 
30 
10% chance for double Thieving rewards


III 
40 
15% chance for double Thieving rewards


IV 
50 
25% chance for double Thieving rewards
