Blackjacking is one of the fastest thieving methods in OSRS, possible from level 45 thieving, you can gain up to 250k xp/hr. It works by knocking out bandits and thugs and then pickpocketing them whilst they are unconscious. In this guide I will cover a method that exploits having a constantly full inventory of coins and food/ food residue to avoid being unnecessarily stunned. You can blackjack until level 99 although at thieving level 91 Pyramid Plunder becomes a faster method. Blackjacking extremely click intensive and takes precision and practice to gain the optimum speeds.
Location
The only location to blackjack bandits is in Pollnivneach a medium sized town which is in the centre of the Kharidian Desert. There are multiple ways to reach it, the easiest is if you have a house in Pollnivneach as there is a house portal just north-west of the town, once you arrive via that method just run east to find the bandits at the northern part of the town of levels 45 and 56 (the Menaphite thugs you will blackjack at level 65 are in the southern part of the town). Alternative methods to get to Pollnivneach are by going through the Shanty Pass south of Al Kharid (using the amulet of glory to it is a fast method) then run south-east or use the magic carpet (which has no requirements to Pollnivneach) for 200 gp. There are also two fairy rings located nearby (requiring partial completion of the Fairy Tale II quest) they are D.L.Q to the east (must cross the bridge to the north-west then run south) and B.I.Q to the north-west.
Requirements
There are just a few requirements for blackjacking. As previously mentioned 45 thieving is required to start and also the following: completion of the Feud Quest, food to recover from hits such as pies and wine (the food item should leave a remnant in the inventory, such as a pie dish and empty wine bottle so you always have a full inventory) and the rogues outfit. You can use noted food items on the banknote exchange merchant in Pollnivneach for 5 gp per item, there is no need to bring extra gp as you will make more than enough gp from blackjacking to cover the first exchange anyway. If you don't have a huge amount of food, for instance if you are an ironman then you can go to Ali the barman and purchase wines from him, both these options will prevent you from having to leave Pollnivneach. When you get to the Menaphite thugs it makes sense to just use the bar as they are in the same location so will save more time than going and un-noting, though both are quite fast. You will also, most importantly, need a blackjack which is a club like weapon with a crush style attack. There are three variants of blackjack, oak, willow and maple and each variant has a regular, offensive and defensive version though they can be all used to lure and knock out bandits and thugs. Each blackjack has exactly the same knock out chance, only your thieving level will increase the knock out chance. As you are given a willow blackjack as a reward for completion of the Feud Quest you should just use that.
How to Blackjack
Once you have the bandit or thug lured you should right click and select “knock-out”, then when he's on the floor quickly right click and select “pickpocket”, you should be able to get 2-3 pickpockets in this time, depending on your ping (finding a low population world with a low ping is very beneficial). As soon as the thug or bandit stands up just quickly knock him out again and return to pickpocketing. If you fail the knockout or pickpocket timing and attempt it when he is standing up you will be hit taking damage and he can become aggressive, you will also be stunned for 5 seconds, just wait and then restart the process after healing if necessary. The reason we use max inventory with cash and 27 food items/ food residues is so you don't have to open the coin pouch to continue, also when you thieve from an unconscious bandit/ thug you just receive coins directly to your coin stack. When the thieves/ bandit are conscious if you attempt to pickpocket by accident (instead of knocking out) it will fail by giving the error of a full inventory.
At level 45 thieving you can only blackjack the and thieve from the level 41 bandits (distinguishable by the big white beards), at level 55 you should move to the level 56 bandits (which have no beards). You should lure the bandits into a building so they are easier to blackjack/ pickpocket as they can't move around as much. One of the best locations to lure the bandits is into Ali's Dye Shop, the most north-eastern building in Pollnivneach. If Ali is in her shop just open the curtain then walk away and she should follow you outside, or change worlds to find one where she isn't in her shop if you are having problems with this. To lure a bandit inside right click on a bandit your thieving level allows and lure the bandit, a dialogue will appear where the bandit asks what is it, you ask him to follow you for a surprise. Occasionally they will ask you to go away, just keep trying again and eventually they will follow you. Once the bandit follows you in through the curtains, close the curtains and you can begin to blackjack and pickpocket. The major benefit of using Ali's Dye Shop aside from its small size is the ability to use the ladder if the bandit becomes aggressive, once upstairs you can heal up if need be then once you go back down the ladder the bandit will be unaggressive and you can restart blackjacking. You will find that using that shop is a very popular location so you may have to jump worlds a bit to find an empty location.
As previously mentioned, once you reach level 65 you can go to the south of Pollnivneach and start blackjacking the Menaphite thugs. The building just south of the two camels is a good location. Although there is no ladder in the building but there is no better location unfortunately. There are however some stairs you can climb north-east of the building to reset aggressiveness, make sure you close the curtain to keep the thug inside. Still you will make more experience than at the thugs, and once you get good at blackjacking there should be no need to reset their aggressiveness. Sometimes the thugs can get stuck outside the wall next to the curtain when you are trying to lure them in, just try and allign them next to the door and try again, it shouldn't be too hard. Once in the building, close the curtain as before and start blackjacking. If you like you can continue here until level 99 thieving but at 91 it is faster experience at Pyramid Plunder. When you want to leave Pollnivneach you should use the magic carpet to a location with a bank, such as Al Kharid once you go through Shanty pass, to re-obtain your teleports/ other desired items as there is no bank in Pollnivneach.