Aliens: Colonial Marines’ AI problems may have been due to a typo

Aliens: Colonal Marines' AI problems may have been due to a typo

Aliens: Colonial Marines’ AI problems may have been due to a typo

Aliens: Colonial Marines released in 2013, and the internet was immediately flooded with bad reviews, criticising several aspects from its AI to its graphics and how much the game differed from its original gameplay reveal. 

AI was a particular sticking point for the game, with alien Xenomorphs which stumbled around the game world like drunks, frequently getting stuck in walls running around in circles or stand still in locations waiting to be shot by the player’s plasma rifle. 

As it turns out, many of these issues can be attributed to a typo, the addition of a single letter in a .INI file which mucks up Colonial Marines’ AI. Fixing this error in the developer’s code has been able to fix a lot of the game’s AI problems. 

A modder called jamesdickinson963 on ModDB recently pointed out this severe typo in a recent post, revealing that a game developer accidentally spelt “Tether” with an a to spell “Teather”. Here is a link to his full post. 


    Inside your games config file (My DocumentMy GamesAliens Colonial MarinesPecanGameConfigPecanEngine.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


PC Gamer investigated this issue and played the game both with and without a fixed/typo-free INI file, confirming that the game’s AI sees significant improvement. 

Below is a short video clip which showcases some of the sluggish and erratic movements of the Alien Xenomorph, showcasing a brief section where a Xenomorph stands still, waiting to be shot by the player’s plasma rifle. The clip below showcases the game before this typo is addressed. 

In the second clip, which uses fixed/typo-free game code, we can see that Alien/Xenomorph movement is more reactive, allowing opponents to charge and lunge at players more often and spend less time stuck on walls or standing in a seemingly thoughtless daze.   

With the fix in place, Xenomorphs are much better at keeping track of players and act a lot more aggressively, which could make the game a lot more difficult when battling against a larger number of Xenomorphs. 

While the game remains far from perfect with this fix, it is hard to see this change as anything aside from a significant improvement for Aliens: Colonial Marines. It is amazing how much can go wrong because of a single typo.

Would Aliens Colonial Marines have gotten a better reception if it released without this typo? You can join the discussion on Aliens: Colonial Marines’ AI problems originating from a typo on the OC3D Forums.