USB stick is necessary for this to work.
- Insert USB stick into PS3. You should see it under PS3 games saves section at first or second place in the list.
- Go to Sanctuary, save and exit, then completely exit the game.
- Copy Borderlands 2 "Profile Data" file to USB stick (file description is visible when file is selected).
To do this click triangle button and select "Copy" and select USB stick as target location.
- Load your game and use as much keys as you want.
- Do not attempt to do anything else, just save and exit, then exit the game.
- Remove "Profile Data" file from PS3 save folder.
- Copy "Profile Data" back from USB stick to PS3. This time you will not have to select destination.
After this step all keys available before making a copy of profile data will be restored. Start game and use them again if you wish. Just make sure to make a copy of "Profile Data" file right before using your keys and don't do anything except looting that golden chest. You will lose any profile-related progress, only character progress and items will be preserved.
BTW, you may want to make a copy of all save files to another USB stick just to be sure that they are safe.
Here is video on Youtube which shows it in action: http://www.youtube.com/watch?v=CNX1RRcf_Ss
If it is not working for you then you are not doing it right. Try reading the instructions again.
- Confirmed working at March 19, 2013 on latest version of the game at that moment and not hacked PS3.
PS3 Cheat #2
- If you have a second controller and save game, make sure you use shift codes after you've loaded both characters.
- You should get golden keys on both characters.
- Make sure you always use the same character for p1 and the same character for p2.
- Enter the game in Sanctuary.
- Use your keys on p1 and then p2, and take and do whatever with the gear.
- Hit the PS button and exit the game.
- Start the game again.
- Load p1 and p2 with the same characters as before, and p2 should have retained all the keys while p1's keys are gone. You can do this an infinite number of times.
If you are playing online with one of your friends and have an item they would like (or visa versa) it is possible to duplicate the item so you both have it
To do this follow the steps below:
- Equip the item you want to duplicate.
- Start a duel with that player in your online game and put the item you want to duplicate as the prize.
- When the duel starts UN-equip the item and drop it on the floor
- Now run out of the battle area, therefore losing the battle
- Your opponent will now be victorious and wins the battle and the item
- Now simply run back and pick up the item you dropped on the floor and you both have a copy!!!!
You can do this for multiple items at a time and as many times as you want
NOTE: You cannot duplicate an item above your level as you are not able to equip that item, but if your playing partner is of a high enough level, simply trade with them and follow the steps above
- Make a copy of character save file to USB.
- Place any item (up to 4 items) into Claptrap's secret stash.
- Restore character save file from USB.
You will end up with two identical items – one in the inventory and another one in the Claptrap's secret stash.
To duplicate more items at once you can start the game with two characters, drop items with one and pick them up with another and then restore character data for the first one. Same is true for network game. If you have a copy of your's character data then you can drop any items on the floor, let other players pick them up, then exit and restore data.
Glitch back into The Lost Treasure of the Sands chamber after Leviathan is dead
In the end of the first DLC "Captain Scarlett and her Pirate's Booty" there area a room with a pyramid. There are 6 chests in it with relatively good loot (blue+) in the center at the top and 1 additional secret chest in the bottom. Usually you can visit this room only twice per character and you are supposed to kill Leviathan each time but there is a way to visit this room as many times as you actually want and loot all chests on each visit.
Please note that you can do so at any moment. You can revisit these chests right after killing Leviathan or just come back later. The only difference is that Leviathan's body will be visible right after killing him and you will start inside of him.
Try to use this video guide: 
There are multiple other guides on YouTube with slightly different methods or with Leviathan's body visible but all of them in general are the same.
- Go to the other side of the Leviathan's room over invisible fin and body.
- Climb his body using invisible platform in the invisible corner (proper jump at this platform is based mostly on pure luck, but you may discover your own way to do so).
- Go closer to the wall using one of the provided visual guides to avoid fall off.
- Run towards, or jump, to the rock below and go through the wall.
It's not as hard to do as it seems and don't forget 7th chest at the bottom! :)
- Confirmed patched as of August 29, 2013 (and non-working) on September 2, 2013 on latest version of the game at that moment on PC.
Moxxi's Upskirt Glitch
Adult content alert!
Well, it's only a panties and it's sort of perversion but why not? Make sure Sanctuary are in the air and use this video guide: 
There are other guides on YouTube but most of them describes much harder way to go to the same place. So, you better try this method first and refer to other guides only if you absolutely can't reproduce this one. :)
To properly jump as in the video you have to jump to the left from the place where you would like to land because there are invisible wall on the way and then move to the right while already in the air to avoid hitting this wall.
ALTERNATE METHOD When you go to Pyro Pete's bar, if you grenade jump up into the sewer tunnel where Pyro Pete jumps out, you can also do the Moxxi upskirt glitch. You just walk into the jail cell with her, or wait for her to come out, and you're all set!
- Confirmed working at February 12, 2013 on latest version of the game at that moment and not hacked PS3.
Easy Anarchy x600 for Mechromancer
Mechromancer with Anarchy skill tree can rise her damage output by 1050% to solo bosses but it is usually hard to do so - because you have to kill something or reload gun when clip is empty to gain anarchy stacks - and will start to loose them if you reload your gun too early, or lose all stacks at once if you die or early-reload without Discord skill.
So, to easily get x600 stack without risking to lose whole stack somewhere in the middle do the following:
- Find any fast-reload shotgun with only 2 bullets in the clip (first anarchy skill will reduce it to only 1 bullet) which consume 1 bullet per shoot (3 bullets clip gun which shoots two bullets at once is fine too).
- Go to Marcus' shop in the Sanctuary and start shooting target.
- Go and buy more shotgun clips when you need.
Try to use this video guide: 
Save file editing
Written here is the way to do this on PS3. This should also work for Xbox and PC, but I have only done it on PS3, and do not know how to correctly extract the save file on Xbox and PC.
For the PC, just use Gibbed Save Editor to open and edit your save files.
This also seems to work "offline" as well as "online" as gearbox does not have a competitive range for online play and since none exists, this is why a lvl 1 can play with overpower lvl 8 host, At the moment gearbox is not checking file saves and from the look of online play, none will ever exist, But.....even if you max out your character with massive skills and weapons once lvl 72, most enemies when on third play trough *UVHM* will still pose a challenge and on overpower lvl 1-8 will pose the biggest challenge, so you still cant take away the run and gun aspect of the game even by cheating.
Working as of 5/25/14
ALWAYS REMEMBER TO KEEP A COPY OF YOUR ORIGINAL SAVE FILE JUST IN CASE!!! Do NOT blame me if you screw this up!
1: First of all, you'll need a USB flash memory stick(FAT32 formatted), and a computer. after getting those, you need to download and install these programs(direct download links in parenthesis):
- Microsoft .NET framework 4 (Media:http://www.microsoft.com/en-us/download/details.aspx?id=17851)
- BruteForce 2.1(Media:http://www.mediafire.com/download/impp1jddbd1bhmj/Bruteforce2.1.rar). (There are newer versions of it, but haven't tried them)
- Bruteforce Dependencies(Media:https://dl.dropbox.com/u/37938765/Dependencies.rar)
- Gibbed's Save Editor(Media:http://blog.gib.me/wp-content/uploads/2013/04/saveedit_r155.zip)
2: After installing all above items, put your USB stick in your PS3, and go to the "Saved Data Utility(PS3 TM)" Folder in your XMB Game category. Find your character's save file(NOT profile data), push triangle, choose copy, and choose your USB stick as copy destination.
3: After copy completes(should take about 5-10 seconds), take the USB stick out of the PS3 and put it in your computer's USB port. When you open the USB stick, there will be a folder named "PS3" on it. Cut/paste this folder to your desktop(or copy it and delete it from the USB stick, whatever floats your boat).
4: Open BruteForce Save Data Tool. Click the ... to the right of the address bar, and browse for the folder location(should be something like C:\Users\(your PC user name)\Desktop\PS3\SAVEDATA\(your PS3's ID no.)-SAVE-SAVE0001\) and click ok. When you do this, the save file will pop up in BruteForce.
5: Click the button "Decrypt PFD", click Yes on the first dialog box popping up, and Ok on the second. A warning will message will show in the bottom right section of BruteForce, ignore this warning, as it means nothing for what you're doing. Minimize BruteForce and open Gibbed's Save Editor.
6: Click "Open". Choose PS3 Save Files(.sav) instead of the standard PC Save Files(.sav) right above the bottom right "Open" button. (This is REALLY important, if you don't do this you'll only get an error message instead of the save file!)
7: If you've done everything correctly you should see your character's info popping up in Gibbed. Now have as much fun with your character as you wish. Most of the tabs are self explaining, but I'm gonna give a short explanation for them, at least those I have knowledge of:
- General: here you can edit your character's level and exp earned, as well as skill points for the skill trees.
NOTE: Gibbed's save editor works all the way up to Overpower Lvl 8 Side Note You can not award yourself badass points, or Golden keys
- Currency: here you can add any credits you need or want.
NOTES: I'm not sure if you can add Seraph Crystals without having in-game defeated one of the Seraph Guardiands(Pete The Invincible, Voracidous The Invincible etc.) without crashing the save, I Haven't tried this myself. Also, no matter how many Torgue Tokens and Eridium you enter, you won't get more than 999TTS and 500E, as these are the in-game max limits.
- Fast Travel: I haven't tried to mess with this myself, but it looks like you can activate any fast travel point in the game without having to find it first.
- Backpack: This is, IMO, the really cool one. Here, not only can you synchronize your current equipment to your character's current level(levelling up your Infinity Pistol from LVL 30 to Overpower Lvl 8 gives it approx. 126000 base damage, and the best critical I've gotten so far is with a (Corrosive) Vengeful Infinity on a loader, about 1,1 MILLION damage!!!), you can EDIT them, replacing different parts from one manufacturer to another. I found out that if you have an Infinity Pistol, and swap the original Vladof Sight with a Hyperion Sight, you get a 30% accuracy boost. Also, and even more awesome, you can MAKE ANY IN-GAME EQUIPMENT AND WEAPON. Just click "New Weapon" or "New Item", and go nuts. In order to make, as an example, an Infinity Pistol, you just need to choose the right weapon parts in the roll-down fields that comes up when you click "New Weapon".
NOTE: some parts MUST be there to make a specific weapon. In order to find out needed parts, find the weapon info on(as an example) BL2's wikia page. There are probably a billion websites that have this info, google it and you'll find boatloads of info. Also, remember to hit the sync button when you're done making the weapon/item, in order to get it to your level. If you don't do this, it will only be level 1 when you load the game.
- Bank: this is exactly the same as the "Backpack" tab, but for your vault in the Sanctuary HQ.
NOTE: Claptrap's Secret Stash items will NOT get affected by what you do in Gibbed's. You'll have to take items out of there and keep it in your inventory or in your HQ vault if you wanna mess with them.
- Raw: I have no experience with this tab, and don't know what happens if you screw around in there.
8: when you're done with going nuts and editing your stuff, click "Save", and choose to overwrite the pre-existing file. Close Gibbed's, and go back to BruteForce.
9: Click the "Refresh" button to the right of the save file location window. The info in the lower right part will change.
10: Click "Update PFD", and choose "Update PFD(full)" in the dropdown.
11: Click "Encrypt PFD", click Yes in the dialog box that pops up. Close BruteForce.
12: Move the "PS3" folder on your desktop back to the USB stick, and put the USB stick back in the PS3.
13: Go to "Saved Data Utility(PS3 TM)", open the USB stick, locate the save file and choose to copy it to the PS3. Choose to overwrite when you get asked if you really want to.
14: That's it! If you have done all things correctly, you now have better weapons and equipment when you start the game and continue your playing!
Have fun :)