Originally Posted by
havokman
Even setting aside the age mechanic, there is a second reason why "metarushes" are heavily incentivized.
Xenos mobility is extremely high on both the tactical and strategic level, and the only decent counterplay marines have is extreme aggression. The only other real (albeit inferior and somewhat miserable to play through) alternative is (ab)using megaFOBs.
On the tactical level, combat is centered around either pursuing fleeing xenos or denying xenos the ability to flee (mostly with stuns). Stun weapons are highly situational or limited to a small fraction of marines, so chasing is the default way to kill Xenos. To reliably kill even the slower xenos without the use of stun weapons requires pursuing them across multiple screens worth of distance while whittling down their health with weapons that deal slivers of their health per hit. Marines going alone or in small groups for extended periods are extremely easy for xenos to wipe, so the only "effective" strategy for marines is to move in large groups and chase down every xenos they see that they can keep up with until they either kill it or run into enough xenos to stall their charge. Xenos usually flee towards their hive because there are unlikely to be undetected groups of marines between a wounded xenos and safety, so this naturally leads to retreating Xenos drawing the bulk of marine forces straight towards the xenos hive until the majority of Xenos forces confront them and attempt to push them back. At this point one side is either wiped out, or falls back to a choke point at which point the engagement turns into a prolonged slugfest until one side is broken by attrition and forced to retreat (and the chase continues/is reversed).
The strategic side is simple. Marine strategic mobility sucks. Command has to flail about communicating orders and coordinating different elements of the Marine force, then Marines have to slowly advance as a coherent force, clearing weeds and traps and breaching walls, until they eventually arrive at the destination. Meanwhile, the Queen barks an order and the majority of the hive can independently move to any uncontested location on the map in under a minute. This means that Xenos get to pick their battles if marines give them a chance, and xenos picking their battles means individual squads and entire FOBs being wiped out to the last man and last cade line because there is very little a small fraction of the marine force can do against the majority of the hive besides be a speed bump. There are *exactly* two ways to deny xenos the ability to pick their battles. Either a) build a megaFOB, so there is only one battle for Xenos to pick, or b) keep charging at the hive until the marines reach the nesting areas/ovi'd queen (since the hive is the one location that Xenos might actually defend to the death), or until the entire marine force charges into the grave. MegaFOBs are massive, exhausting, time consuming slugfests that rely on using concentrated marine manpower and concentric layers of defenses to create an environment where the difficulty of securing marine kills/captures and the inevitable occasional screwup by individual xenos attrition the hive slowly into oblivion, despite the massive disadvantages marines face on the defensive. Do-or-die charges are, of course, functionally indistinguishable from metarushes if Xenos fail to put up sufficient resistance.
Take these two together, and it is obvious why CM gameplay will swing towards either the rush/chase or FOB meta. Today the problem is metarushing. A while back it was dirty marines and their horrible unfun megaFOBs. Tommorow? Pick one or the other, unless some serious rethinking of CM's mechanics is done.
I remember Tom Dinkle trying a similar strategy on the marine side. We eventually won that round, but Dinkle had to practically beg the marines over commander announcements constantly to follow his tactic of repeatedly falling back to hydro after pushing xenos up to the cave entrances with ballsy charges and CAS/OBs. And if one CO could get marines to follow an actual strategy, it would be Dinkle.