Upon researching this patch, ResetERA readers noticed something in the moddb.com notes that somehow escaped the gaming community at large in October 2017: the discovery of a one-letter typo in A:CM’s INI files. As moddb.com user jamesdickinson963 pointed out last year, the game’s “PecanEngine.ini” file references a “tether” system in assigning AI commands to the series’ infamous monsters (which I’ll call “xenomorphs” for brevity’s sake, even though that term isn’t necessarily the right one). However, one of its two mentions of the term “tether” is misspelled as “teather.”
Dickinson’s post alleges that this command, when spelled correctly, “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.” Thanks to how the engine parsed this typo, it never caused any crashes; instead, the engine ignored the unfamiliar term. Thus, the game’s monsters never received the smarter, useful information that had been programmed from the get-go. Instead, they often ran around like in the infamous image below.
On Friday, Ars re-downloaded and tested the game, exactly as served by Steam, through the opening beats of two missions. Then, we replayed those missions after editing the “teather” typo in the aforementioned INI file. In both missions, xenomorph AI improved dramatically once the typo was corrected, with monsters immediately taking advantage of elevated attack positions, hiding points, and multi-monster flanks. The difference is night-and-day