Borderlands 3, like its predecessors, isn’t a game known for taking itself too seriously; however, the series isn’t without its secrets, Easter eggs, and fan theories. There’s one big mystery that bridges the gap between the 2nd and 3rd Borderlands games that many fans have been waiting for an answer to in one of the game's story DLCs.
So far, fans attempting to get to the bottom of the mystery once and for all have come up short. That does not mean there isn’t plenty of evidence that points in one direction, however. If not in the upcoming Arms Race DLC (where it's not likely), fans may have to wait on a formal explanation for one big mystery in Borderlands 3: the relationship and creation between characters like Zer0 and FL4K.
Robotic Zer0 Theory
One recurring theory in the Borderlands community is that Zer0, the assassin class character from Borderlands 2, and FL4K, the Beastmaster class character from Borderlands 3, are related. This in turn is predicated on the theory that Zer0 is not a human but is actually a robot. This is hinted at in-game, with characters like Angel commenting that they aren’t sure whether Zer0 is human or not, but Borderlands 3 gave players even more reason to speculate that Zer0 and FL4K are related.
To start with, Zer0 only has four fingers which, despite the Borderlands series’ cartoon art-style makes the character unique among the Borderlands 2 playable characters. Zer0 also doesn’t run out of breath when running like the other player characters do, and though it may be related to the mask the assassin wears, the character’s voice sounds robotic as well.
FL4K and Zer0's Connection
FL4K the Beastmaster is confirmed to be a robot despite ironically looking slightly more superficially human than Zer0 does. However, without his trademark Borderlands 3 coat, FL4K’s body is revealed to be far slimmer, resembling Zer0’s. Both characters have numbers in their names, 4 fingers, and both can cloak. To add to the evidence, the Sir Hammerlock vs. the Son of Crawmerax DLC for Borderlands 2 involved Zer0 being helped by a character named 0ne, which could imply that Zer0, 0ne, and FL4K are all a part of the same line of robots that were mass produced in some way.
It could also imply that Zer0 and 0ne are more closely related to one another than they are to Fl4k the Beastmaster, who might represent something like a different 4th edition or design that Zer0 was a prototype for. The fact that Zer0 and 0ne both have a “0” in their name and are named after numbers themselves distinguishes them from FL4K but doesn’t totally undermine the fan-theory.
FL4K refers to Zer0 as seeming “familiar” when he meets him for the first time, which heavily implies that even if they are different models of robot, they ultimately have the same creator. After the defeat of Katagawa Jr., Zer0 wonders how the game’s villain was able to mimic his “suit," implying that Katagawa Jr. may have discovered the technology with which Zer0 and FL4K were made or the facility in which they were created.
The biggest mystery that remains to be solved, however, is why Zer0 has to keep their robot identity a secret – or perhaps doesn’t know about it – while FL4K is explicitly a robot. It seems likely at least that Zer0 was an earlier model, which perhaps comes with its own side-effects like memory loss or safety mechanisms which were tweaked in later models before the Borderlands 3 story.
Borderlands 3 has released 4 story DLCs already but could still have a few more in store before it finishes its cycle. It’s also possible that something is being hinted at which could make a big return in a future Borderlands game as a central plot point. With the Psycho Krieg and the Fantastic Fustercluck DLC a reminder that Gearbox is far from finished with its Borderlands 2 characters, many fans will be hoping to uncover the root of Zer0 and FL4K’s connection in the franchise’s future.
Borderlands 3 is out now for PC, PS4, Stadia, and Xbox One. PS5 and Xbox Series X versions are in development.