Tips from an Engineer

[Karmac]

These are general tips that some of you may or may not know regarding information on marine FOB's and defensive structures.

Tip #1: Almost everything can be melted, whether you're acid spitting it to death or literally melting it, practically everything an engineer builds can be destroyed in this fashion, including Sentry Guns, though they take significantly less damage from this.

Tip #2: Flipped Tables & Plasteel Barricades block Boiler globs. They do not stop the gas spread, but you won't get the glob any further than the defense you hit. False walls, when closed, Girders, False Doors and Airlocks do stop the spread of gas, so keep an eye out for marines attempting to use any of these structures to pre-emptively deny boiler bombards.

Tip #3: Sentry guns have less range when on 360*, I believe it's around 6 tiles. When on Directional, they have a 180* field of fire, meaning to sneak up on one, you must literally sneak up from behind it, they also have farther range when locked to a direction, roughly 8 tiles or more I believe.

Tip #4: Mines, if the marines are smart mines will never be placed inside or close too the FOB, as they run the risk of harming marines and their defenses, so you shouldn't have to worry about them in those areas.

Tip #5: Racks, Barricades and Flipped Tables can be pounced through, this takes time and will bonk you, but is the cheapest most reliable way to get past them.

Tip #6: Crushers bonk on R-Walls, False Doors, Plasteel Barricades and Reinforced Glass (If their momentum isn't high enough). Keep an eye out for these and make getting rid of them top priority, and don't forget that the Crusher has a significantly lower chance to deflect shots while bonked, make sure you don't waste your Crushers to a defense line filled with ahotgunners.

Tip #7: With the design of an FOB kept in mind, it can usually be easier to just incapacitate the marines staffing it, rather than actually breaking into the FOB itself. And if sentry guns are giving you trouble, remember that their AI isn't terribly smart, if it can see you and you're within maximum range, it'll shoot at you till it runs out of bullets. Hiding behind walls and girders is the best way to accomplish this as they can take a decent amount of punishment before breaking.

Tip #8: Always try the psychological approach, as Derpislav mentioned below, a good show of force or pretending to look like you have a plan can force marines into calling a retreat, though this will most likely just weed out the cowards and leave the veterans and foolish behind, both of which are the more deadly variety of Marine.

Tip #9: A decent strategy I've recently noticed due to the influx of Drone players because xeno players just can't get away from being able to use huggies, is running up as close to a gunline as you can and spamming resin walls, this wastes marine ammunition, blocks sentry fire and makes it easier to move down what would normal be a 'kill-death corridor of very bad times'. This is basically adapting a 'mobile cover' strategy that would be useful in pretty much any situation where you're genuinely going head to head against the Marines.

More coming.

[Sarah_U.]

Racks barricades and flipped tables can be pounced through without getting bonked / KO'd if you land on a marine or in certain conditions I forgot.

Mines are very often placed in FOBs so...

Good tips overal.

[Derpislav]

Every FOB can be broken by attacking the weakest link. The human component.

Get the entire hive in there. Make sure marines see how many of you are there. Melt anything you can without risk and just stand there menacingly without attacking. Look like you have a plan.
If you make enough of a show, marines will soon start screeching "TOO MANY OF THEM, WE MUST EVAC!". That leaves the FOB defended by just a few smart ones, in complete chaos.

[Swagile]

Always right click flares, as you can hide mines RIGHT under a flare with barely any sprite difference.

[immaspaceninja]

Sentry gun's shooting radius in 360 mode is just 3 tiles tho.

Also, crushers can break fake walls with one full-speed charge, so keep it in mind if you're facing some smart ayyliums.

[Karmac]

Sentry gun's shooting radius in 360 mode is just 3 tiles tho.

It's at least 6, trust me.

[immaspaceninja]

It's at least 6, trust me.

If you're talking about the RADIUS, then no, not 6 for sure.

[Crab_Spider]

Mines can be disabled with one slash from behind from all castes, and the kicker is, you take no damage.

Sentries can FF each other , remember that when you're trying to disable the Rasp turrets and need to be safe.

If the mine placers are bald, they will set them up side by side, one tile next to each other. One misplaced grenade or crusher will fuck these badly placed defenses up.

If a FOB actually uses walls, corrosive spit them down and have the Elites or Ravagers smash the girders down.

Girders/Displaced's can be used as bullet shields against idiot Marines or the friendly neighborhood sentry gun.

[Swagile]

Turrets fire at people behind corners, but don't neccessarily hit you if you are hidden behind the corner well enough.

Hence, if you truly have the patience, you can sit behind a corner and wait till the sentry runs out of ammo.

This is a strategy that you would employ only if your a patience person + your a really squishy caste (ie. runner), and the turret isn't defended but barricaded / marines have to worry about something else than their turret firing on you.

[Renomaki]

A sentry can be knocked down if you acid spit at it enough, which can allow you to close the gap with marines more easily and punch through weakly defended areas that are relying too much on a sentry to hold them.

As a boiler, your gas blocks a sentry's line of sight, allowing xenos to move safely within it's normal range of fire, or maybe even rush it to take a few quick jabs.. Keep in mid it'll still blast you if you get too close, though.

Many marines tend to hug (stand on the same tile of) their cover, thinking they are protected from ranged attacks. They aren't. If you fire a spit directly at them (not in their general direction), you can bypass their cover and hit them. It won't work against marines standing a tile behind cover, though.