"Who You Gonna Call?" Achievement - Solo Guide

A short guide on how to get the achievement in singleplayer, without cheats or controllers.

Intro

You will need a tool that artificially changes player count to 4, tricking the game into believing you play in a full Co-Op squad, thus rewarding you the achievement upon completing the mission(s). It's not my creation, I found it here. Tool is made in late 2014 as an update to existing B1/B2 tool, to work with the Pre-Sequel.

Apparently the added difficulty also grants better loot drops but I didn't bother to verify this. Meaning you could continue playing with it to ease the grind if you so desire.

Guide

1. Download the tool[1drv.ms] (inside the .zip).
   
2. Run game, select desired character, click Continue (crucial!).
   
3. Alt+Tab to desktop and run the tool. Click Scan and move slider all the way to the right.
   
4. Alt+Tab back into the game and Start the "Sub-Level 13" mission(s) in Outlands Canyon.

It is sufficient to run the tool just before turning in 2nd mission and still get the achievement.

Outro

You'll know it's working when you get a 5 second timer during map transitions and being able to pick up ammo even if you are maxed out. Finish it and the achievement will pop out. To stop the tool player scaling effect close the game completely as well as tool itself.

[Midori]

5/20/25 WORKING, before turning in the first mission I opened the program, scan and turn all the way to the right, then return it and got the achievement, thnks!

[Utopia]

Still works in 2025

I turned it on before turning in the 2nd mission and it worked

[Nilex]

It's a long shot but you could also try "Borderlands Difficulty Mod" on moddb. It does the same thing as this tool but for Borderlands 1 & 2 (non-Enhanced of course). Very likely won't work for the same reasons though.

[aljacJR]

I checked, it doesn't work, you can add it back !
and thank you for answering

[Nilex]

@aljacJR
Logic suggests no (different executable, memory footprint, content, etc) so I doubt it.

[aljacJR]

Hello, do you know if this works for Borderlands GOTY Enhanced or not?

[Michiru_K]

2025 still working. Cheers!

[hot]

You may only need to turn in the mission with 4 player enabled

Why I think so:
I save quit after I completed the mission but BEFORE I turned it in (I wanted to travel back to the original door to save time) and it turned single player ON when I loaded back in. I used the tool to set it back to 4 players, then turned in the mission and the cheevo popped.

[Nilex]

@Ragenarok
Afraid not, those two really depend on legit co-op. Recommend piggybacking in one of many existing topic on the subject in the forum. There's bound to be players still looking for the same thing. I remember doing the same and it went pretty smooth. Maybe pick a larger topic so more people get a notification.
Thanks for all the rewards peeps!

PS
It should continue to work, doubt they gonna suddenly update the engine of a 10 year old game so no worries. And if they do it'll come in a form of a $60 remaster, y'all know the drill :)

[Ragenarok]

Would this also give you the possibility of getting the 2 coop only Vault action pack options as claptrap?
Medbot and sensless sacrifice?