TL;DR provided at the bottom of the guide. Simple stuff.


So. I just played a round of NS2. And I witnessed something that made me facepalm SO HARD that my hand went through my brain, flipped twice and landed back on the keyboard to write these words. I'm so mad right now that I can't NOT point this thing out. Jesus Lord God please have mercy on us, poor Darwinian souls.

So. You guys know that aliens like to dwell in vents. Skulks and lerks use them to move around sneakily. Some are out of reach of marines, and sometimes gorges (who cannot climb walls) will use clogs to boost themselves up in otherwise inaccessible vents.
Well guess what, if a gorge does that and leaves his clogs behind, you can use them as a marine to climb into these vents and surprise the aliens that absolutely not expect you to be there!
That's what is called a pro-gamer move ! (yes I'm memeing right now, don't judge).

So. I was playing my round as marines, and I see two clogs on top of each other, leading inside a vent. Those were left behind by a brave gorge who escaped this fate. Being the smart player I am (shush, you), I look at my map, and I see aliens around, and my progamer sense tells me I should get inside to surprise some skulkos. I get in, I see a skulk, I unload my rifle, and I get a kebab of two skulks with one mag. GREAT ! I proceed to tell my team mates "There are good clogs in [insert name of the room here] leading into a vent, we should use them to trap unsuspecting aliens!". Using the enemy's tricks against it to gain the surprise effect is common sense for a veteran NS2 player.
But I ♥♥♥♥ you not, after my frags I die some time later (heroically ofc), I respawn, and go back to that place with the clogs... only to see a guy, crouched in front of them, axing them to oblivion.
WHAT. THE. ACTUAL. ♥♥♥♥.... MATE?
These clogs were not obtrusive in any way, and they were so damn useful. But that fool just thought it was a good idea to axe them down. Yeah ok. My heart died inside a little at this moment. Jesus Lord God have mercy on that poor soul, may I he never be on the opposite team because I'ma go medieval on his ass (and no, I'm not full of salt!... maybe a little).

So. Here I am telling you this story so you never do that guy's mistake anymore, and you start playing smart like yours truly, humble Jackson, here.

PS: Also, I remember in a 6v6 competitive match, a Lerk that was healing in an inaccessible vent was killed by a marine who climbed a clog tower, because the aliens left the clogs there. It was hilarious, and a good move by the marines.

Here are the actual protips about clogs leading to vents and clogs destruction as marines.

MARINES

You don't need to destroy all the clogs you see, so stop doing it.
Why?
-Some clogs are poorly placed or inobtrusive so they're not a real problem. If it's not a problem, don't try to fix it.
-When you stand still to destroy clogs you put yourself in a vulnerable position. You don't want to do that if it's not for a good reason.
-It wastes your precious time, especially if you don't have a welder or a flamer. You could use this time to move up and join your team mates for a push, or destroy a harvester, I don't know, something more useful maybe!

Plus, you especially don't want to destroy clogs left behind by a gorge and that lead to a vent. BECAUSE YOU CAN USE THEM TO GAIN AN ADVANTAGE. You can jump on them to self-boost into a vent you're not supposed to go in. You can surprise the aliens inside for an easy kill! Why on Earth would you waste your time getting rid of something useful for you ON PURPOSE? Don't do it people.

ALIENS

GORGE

First of all, going into a vent as gorge can be a necessity or a shortcut, and it has its uses. Of course you need to self boost in those vents by stacking clogs under you to reach them.
If you're a gorge who camps in a vent on purpose though (a "vent-gorge"), then you're a huge troll and you deserve a bitchslap, you.
On the other hand, if marines are stupid enough to waste their time on you, useless gorge, then they're idiots too LOL !
Anyway.

Yeah, my point here is just that if you ever use clogs to self boost in a vent and if you're not in a hurry, always look back at some point and destroy some of your clogs so the marines cannot access a ventilation they're not supposed to go in ! It can save your life.
If you can't access your clogs anymore, just place more clogs in random places until you go beyond your limit, then your previous clogs will be destroyed. Problem solved.

And if a gorge team mate says:
"Bro, why you destroyed my clogs, eRmAghErD?"
answer with:
"You're supposed to be on the field healing your allies, not camping in a vent!"
Works (nearly) every time !

SKULK and other lifeforms

-If you see a clog that marines can use to self-boost into a vent they're not supposed to go in, take a moment to destroy it. It could save your team mate's life, or prevent a Fade from being trapped! Be a team player.

MARINE
- If you see clogs that you can jump on to get into an otherwise inaccessible vent, use them to your advantage.
- If you see clogs that you can jump on to get into an otherwise inaccessible vent, never destroy them.
- If you see clogs that are not a problem (blocking a path, blocking the view), don't destroy them.
- Only destroy the clogs you need to destroy, leave the rest.
- PROTIP: use Welder, Flamethrower, or Cluster Grenade to get rid of clog walls.

ALIEN
-If you see a clog leading into a vent that marines can jump on to access this otherwise inaccessible vent, take a moment to destroy it!
-If you're a gorge using clogs to go into a vent, take a moment to destroy your clogs so the marines cannot follow you. Or make sure the way is absolutely inaccessible otherwise.