How a Single Typo Crippled Aliens: Colonial Marines AI for Five Years

Five years. That's how long Aliens: Colonial Marines shipped with broken AI, all because someone typed "Teather" instead of "Tether."

The Discovery

In July 2018, modder jamesdickinson963 was digging through game files while working on his popular "TemplarGFX's ACM Overhaul" mod when he stumbled upon something that would become gaming folklore.

Buried in a configuration file (PecanEngine.ini), he found this line:

ClassRemapping=PecanGame.PecanSeqAct_AttachXenoToTether -> PecanGame.PecanSeqAct_AttachPawnToTeather

Notice the problem? The destination class is misspelled as "Teather" instead of "Tether."

Why It Mattered

This wasn't just any line of code. The AttachPawnToTether function controlled critical AI behaviors:

• Tactical positioning - Aliens choosing where to attack from
• Patrolling - Movement patterns and area awareness
• Target zoning - Flanking maneuvers and group dispersal
• Environmental navigation - Using vents and holes to ambush players

Because of the typo, AttachPawnToTeather pointed to... nothing. An empty function. Every time the game tried to make Xenomorphs behave intelligently, the call simply failed silently.

The result? Aliens that mindlessly charged at players in straight lines, standing upright like confused puppets rather than the terrifying hunters they were meant to be.

The Community Reacts

When jamesdickinson963 posted his findings on ModDB, the gaming community exploded. Here's his original announcement:

"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."

Players who applied the fix reported dramatic improvements:

• Xenomorphs now crawled on all fours more frequently
• Enemies flanked through vents and environmental openings
• Groups dispersed tactically instead of bunching up
• Combat felt genuinely threatening for the first time

Before and After

The difference was stark. In the original release, Xenomorphs would:

• Run directly at players standing upright
• Ignore environmental paths and vents
• Cluster together in easy-to-kill groups
• Show no tactical awareness

After the one-letter fix:

• Aliens performed evasive side-to-side movements
• Used cover and environmental features
• Flanked players from multiple directions
• Behaved like actual predatory creatures

The Bigger Picture

While the typo fix improved the game noticeably, it didn't magically transform Colonial Marines into a good game. As one reviewer noted, "that something does not fundamentally correct all of the various problems with Colonial Marines."

The game's troubled development, including allegations that Gearbox outsourced work while focusing on Borderlands 2, left deeper scars than any single bug fix could heal. But the typo became a symbol of how spectacularly wrong the project had gone.

Legacy

The Aliens: Colonial Marines typo has become one of gaming's most infamous bugs, regularly cited in discussions about quality assurance and the importance of code review. It raises uncomfortable questions:

• How did this pass through testing for years?
• Did anyone at Gearbox or SEGA ever investigate the AI complaints?
• What other games are shipping with similar hidden issues?

For the modding community, it was a triumph. jamesdickinson963 and the TemplarGFX overhaul team had accomplished what a major studio couldn't - or wouldn't - fix for half a decade.

How to Apply the Fix

If you own Colonial Marines on PC and want to try it yourself:

1. Navigate to My Documents\My Games\Aliens Colonial Marines\PecanGame\Config\
2. Open PecanEngine.ini in a text editor
3. Find the line containing AttachPawnToTeather
4. Change Teather to Tether
5. Save and launch the game

Or better yet, install the full TemplarGFX ACM Overhaul mod for additional improvements.

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This story serves as a reminder: sometimes the biggest bugs hide in the smallest places. One letter. Five years. Millions of disappointed players. Game over, man. Game over.