How about to add ability to..

[GeniyEvgeniy]

climb in tunnel as human. Like vietnamese. Let it take a lot of time, but this is cool. Imagine, vietnamese climb out from hive tunnel and throws grenade in queen
VIETNAMESE.jpg

[Chocolate_bickie]

Let marines climb into tunnel but if any xenos are in the same tunnel at the time it's instant death and gibbing because your in a tunnel with a murder machine like a moron

[Freedominspace]

This, while being fun and gimmicky, doesn't add anything and isn't necessary.

[Renomaki]

it would either end with marines abusing it to rush the xenos, or become a death trap that no one bothers to use because xenos will just trap every tunnel they make for easy infections.

[Wibble]

I can see it now, a endless flow of marines popping out of a tunnel and straight into the Xeno's main hive.

[Freedominspace]

I can see it now, a endless flow of marines popping out of a tunnel and straight into the Xeno's main hive.

Either that or the xenos station their youngest in the tunnels to kill any Marines that try.

[Deep Inside Me]

*burrower starts laying traps near tunnels*

[Spetr]

Good idea, please add. Definitely not a xeno main here

[ZhanLong]

climb in tunnel as human. Like vietnamese. Let it take a lot of time, but this is cool. Imagine, vietnamese climb out from hive tunnel and throws grenade in queen
VIETNAMESE.jpg

The problems I'd see with that are that Xenos are usually more snake-like than Marines, which makes it easier for them to slip through tight tunnels, and secondly that, back in the Vietnam War, the Vietcong were very lightly equipped, and thus had an easier time crawling through their tunnels, something the generally larger, more heavily equipped US Soldiers weren't really able to do. This made them send Tunnel Rats in there to scout the Tunnels out, or just blow them up by tossing explosives in there.

In a similar manner, the USCM, with its pretty bulky gear would have a hard time getting through Xenos-dug tunnels, not to mention the sheer suicide it would be to crawl into a cramped space frequently used by walking blenders that bleed acid.

HOWEVER, "Tunneler" Kits for HvH rounds that allow humans to somewhat replicate the Xenos' ability to tunnel could be pretty interesting, as it would allow troops, ammo and material to get to the frontline much quicker, and thus make firefights and besieging fortifications much more interesting. You could balance it out by making the drill or jackhammer (Or whatever would be used to dig tunnels in this case) take a long time to make the entrance, and maybe consume fuel like Welding Tools.

[Asian_047]

Finally, I can immerse myself into Vietcong roleplay