Aliens: Colonial Marines is an infamous game, there’s no denying. Going through many issues and delays during its six-year development cycle (due to developer Gearbox Software working on multiple other projects at same time) it was eventually released in 2013. Reviews were not kind, with the Xbox 360 version sitting at a 48 on Metacritic (the PC version has a 45) as reviewers pointed out the many bugs, AI pathfinding issues and more. With all that said, a big issue behind the infamous Aliens: Colonial Marines AI has been discovered. (Credit goes to ResetEra user JigglesBunny for bringing this to light).

Modder jamesdickinson963 on moddb.com was working on a mod called TemplarGFX’s ACM Overhaul, designed to fix massive issues with the game. He made an incredibly interesting discovery when going through the game’s ini files. Here’s what he found:

A new update will be coming soon with this change included, however after getting reports back from several players on how much this effects the game, I just had to post it now

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

If you fix it to look like the above and then play the game, the difference is pretty crazy!

Why is this line important? There are two reasons :
1) AttachXenoToTether doesn’t do anything. Its basically empty or stripped
2) AttachPawnToTether does ALOT. It controls tactical position adjustment, patrolling and target zoning

When a Xeno is spawned, it is attached to a zone tether. This zone tells the Xeno what area is its fighting space and where different exits are. In Combat, a Xeno will be forced to switch to a new tether (such as one behind you) so as to flank, or disperse so they aren’t so grouped up etc. (*disclaimer* this is inferred opinion, I cant see the actual code only bits)

Whenever the game tried to do this, nothing happened. Now it does!

So there you go. Evidently, you can fix a massive AI issue in Aliens: Colonial Marines by removing a single letter from a single typo. As always, the results of tiny programming mishaps never cease to amaze me. I don’t have the game on my PC to test this out, so if anyone out there reading this would like to attempt this fix, please let me know if you can tell a big difference.