Every time it’s seemingly done and buried, Aliens: Colonial Marines comes back to haunt Gearbox in whole new ways. The game has been subject to heavy criticism and a lightning rod for controversy in the five years since its release. Both Randy Pitchford’s willingness to blame his audience for having high expectations, and a final product which barely resembled the vertical slice demo, have been particular sore spots among fans. However, a whole new problem has been uncovered by modder jamesdickinson963, who has been attempting to fix Colonial Marines with his TemplarGFX’s ACM Overhaul. Apparently the game’s much derided AI was the result of typos within its basic scripting prompts.

In an update, he cited the following discovery:

“Inside your games config file (My Document\My Games\Aliens Colonial Marines\PecanGame\Config\PecanEngine.ini) is the following line of code :

ClassRemapping=PecanGame.PecanSeqAct_AttachXenoToTether -> PecanGame.PecanSeqAct_AttachPawnToTeather

Im sure you’ll notice the spelling mistake

ClassRemapping=PecanGame.PecanSeqAct_AttachXenoToTether -> PecanGame.PecanSeqAct_AttachPawnToTether”

The simple extra letter in “Teather” is much more important than you might think, as it’s responsible for the xenomorphs performing continual lemming rushes into the awaiting guns of the players.

In layman’s terms, this error prevented the xenomorphs from being able to run up the walls, hide in air vents and veer about the players as you would expect. This line of code was intended to explain to the AI what area it was in, the nearby exits and environmental elements. Without the code being able to tether the AI to the nearby zone, it would act as if you were in open terrain without any way to flank the player. It also led to xenomorphs clustering together in small areas, and doing nothing to avoid the player’s line of sight. Without it, they are capable of hiding from players, crawling up the walls and ambushing marines.

The change not only makes many levels substantially more difficult, but it also makes the motion tracker a viable tool in many levels. Prior to this, due to the xenomorphs predictability, it seemed to be an extremely superfluous tool present purely for fanservice. More importantly, it brings to light questions as to how this could not only get past Gearbox’s QA testing, but was not fixed in multiple patches over the past several years.