Here's a list of ALL items and their effect on the Alien

[Captain Capslock]

I had to post this here because Steam won't let me create a new guide.
Spoiler Alert ~ Considering none of these are available from the start.

So yeah. I listed all the tools and weapons found in the game alphabetically below and noted their effect on the Xenomorph. It might be helpful next time someone wonders if Flashbangs or Smoke Bombs even affect the Alien at all.
I excluded the Medkit and Maintenance Jack for obvious reasons. Likewise, the effects on Humans or Working Joes are excluded as well.

Video:

https://www.youtube.com/watch?v=-kT4RxCiouA

List:

Bolt Gun
Stuns the Alien for a brief period of time but takes way, way longer to charge for it to actually make this weapon beneficial.
Contrary to what one might think due to the loud noise, charging the device doesn't seem to attract the Alien.

EMP Mine
Impact on the Alien is completely ignored. Does not activate as a proximity device when the Alien comes too close.
Thrown into a corner, it has the same effect as a Noisemaker albeit it requires the Alien to be near its detonation for it to notice the explosion sound.

Flame Thrower
Simply holding it without firing causes the Alien to move slowly but will never take a step back unless fired.
When hit, the Alien will run off into the nearest vent. When hit at the last moment before it kills the player, the Alien will take a chunk of your health before leaving.
Be aware that even the Flame Thrower produces enough sound to attract the Alien from any location.

Flare
Distracts the Alien for about the same duration as a Noisemaker would. Note though, that the thrown or placed Flare must be in the Alien's line of sight first.
Holding an activated Flare in your hand increases your detection chance, as if standing in a lit room.

Flashbang
Stuns the Alien for a brief period of time when either activated as a proximity device or thrown. It does have its use, but it shares this same effect with items a lot cheaper.

Molotov
Immediately causes the Alien to flee into the nearest vent when either activated as a proximity device or thrown. It shares this effect with a full blast from the Flame Thrower.

Noisemaker
Attracts the Alien from any location upon activation. The Alien will take its time investigating the Noisemaker giving you a brief opportunity of escape.
Note that like with all distraction items, the Noisemaker usually works even when thrown directly in front of or even at the Alien, assuming it hasn't noticed you yet.

Pipe Bomb
Immediately causes the Alien to flee into the nearest vent when either activated as a proximity device or thrown. It shares this effect with both a full blast from the Flame Thrower and the Molotov.

Revolver
Impact on the Alien is completely ignored, assuming there's no secret weakspot I might've missed.
The loud noise upon firing attracts the Alien from any location.

Shotgun
Briefly stuns the Alien when shot. It reloads faster than it takes for the Alien to recover, making this the only weapon that barely stuns the Alien but is still worthwile using as a last resort.

Smoke Bomb
Contrary to popular assumption the Alien's line of sight is in fact broken by the smoke, just as with Humans and Working Joes.
It still seems to have a general idea of your location, however.
Moving through the active smoke seems to slow the Alien down.

Stun Baton
Completely ignored by the Alien.

Some general info

• The Bolt Gun, Flashbang and Shotgun all share about the same stun duration. The Shotgun is the only one of those three that can fire faster than it takes the Alien to recover.
  
  
• The EMP Mine, Flare, Noisemaker, Revolver and Stun Baton have no effect once the Alien has spotted you.
  
  
• The EMP Mine, Flare and Noisemaker all distract the Alien for about the same period of time. This effectively makes the EMP Mine a somewhat expensive alternative to the Noisemaker for when you don't have any left and Working Joes are no current danger.
  
  
• The Flamethrower, Pipe Bomb and Molotov all scare off the Alien for about the same duration. These weapons also all share the possible "Alien knocks you over while fleeing" -sequence.
  
  
• Even the non-effecient weapons like the Bolt Gun, Revolver, Shotgun and possibly even the EMP Mine cause the Alien to bleed.
  And yes fans, it bleeds green.
  
  
• The Stun Baton is the only item in this list that has 0 effect on the Alien at any point. It shares this with the Medkit. Hooray.

[TheTrust<]

Thank you for making such a detailed analysis

[Chaos Epoch]

this should really be a guide and not a topic in discussions.

you should never forget that the maintance jack is a thing, though it's a lot harder to use. it's hard to predict what the alien will do. sometimes it'll jump into the vents and appear near to the sound. sometimes it'll make a beeline straight to it. always make sure you're using it near a vent that you can hop into to make a getaway. or to use it near other humans.

if it's stationery and you're up close, shooting the alien in the face with the shotgun will often (but not always.) cause it to bug out. sometimes it needs a double blast to be sure. it's easier to do this if you managed to jump the alien and it isn't in attack mode yet. best used when you don't have much fuel left for the flamethrower, but can still switch to it if the alien dosen't back away.

if you manage to get into a fight with a survivor and the alien is called midway, the survivor will stop attacking you and will put their attention to the alien, but only if you do so first. if it gets attacked from two different sources at once, it'll bug out. afterwhich the survivor will run away but will still attack you if you try to follow. the same applies if you catch an alien charging towards some poor sob.

[TheCouncil]

Wonderful analysis.

Hey Mimzie, was there a reason that you blocked me? I was hoping to see your playstyle like we discussed.

[North(rly)Drift]

Thanks for the great reference, good to know that most weapons are as futile as I thought.;-)

[freefall]

In the worst case scenario, the shotgun and bolt gun will buy you enough time to switch to a more potent weapon to drive off the alien, but you won't have time to reload an empty weapon (the shotgun is more beneficial in this case, as you can more or less stop its charge with 2-3 shots). Once you've stunned it, immediately switch over to the flamer or a pipe/molotov and and use it before the alien recovers from the shot.

Also, the alien doesn't know how much flamer fuel you have. You can be critically low on fuel and not have enough to drive it off, but if you aim the flamer at it, it will cower back for a brief moment, which gives you some time to back off and pull out a molotov or pipe bomb. Or just hit the button if you're in a lift. The best way to save flamer fuel is to aim it at the alien, then walk in range and burn it for about one second. I find that short taps can occasionally drive the alien back without actually causing it to retreat, and if it already has a resistance to the flamer because you've been using it a lot, you'll find that it takes a lot more ammo to drive it off.

Finally, the flamer's pilot light makes for a decent free light source when you're navigating vents, though the illumination is too dim to really light up darkened hallways. Once I have it, I'd rather use the flamer's pilot light than a flare or the flashlight since it's a lot less likely to draw attention to you. It creates just enough light for me to see without being noticed, and if I do get the Alien's attention through bad luck, at least I'm always ready to deal with it.

[Meowser]

I'll assume smacking the alien in the jaw with a maintenance jack doesn't do much?

[freefall]

Originally posted by AdmiralDropBear ( ͡° ͜ʖ ͡°):

I'll assume smacking the alien in the jaw with a maintenance jack doesn't do much?

It results in you being eaten. :P

[xxgsxrcopxx]

nice list

[Cpt.Haxray]

Fun fact... even though this thread has been dead for a while, its still on the first page. The revolver CAN actually affect the alien, as I managed to use it once to scare away the alien on nightmare mode. Its just super difficult.

You need to empty all 6 shots straight into the alien's head, and he will turn and flee. However, you have to do this BEFORE he sprints at you... meaning theres less than a 1% chance of actually doing it.

It can happen though.

[Darenis]

This is great, thanks.

[Hex: Nurse's Vagina]

The Molotov, Pipe bomb, and Flamethrower remind me of shivs from The Last of Us, you can use them to save yourself if you are spotted. It's like a Get Out of Jail Free Card.

[spectre199]

I've used the Maintenance Jack to hit the wall or other hard objects which brings the alien to you immediately just to deal with the humans. The problem is that you have to hide immediately or get out of the area immediately, the other problem is the alien will stay in the general area you are in.

Another thing I've done to attract the alien to kill humans is firing the gun and then hiding or getting our of the area

[Hollow]

The issue with attracting the Alien is the director AI which always points it at your location, making the Alien appear closer to you then where the noise was that it actually should investigate and where it thus should actually appear. Also if NPCs scream or run the Alien doesn't react to that as the devs of the game forgot to define these actions as noise sources so it's like the Alien is deaf to that.

The thread's info part about the shotgun is partially wrong. Only if enough of the shotgun's projectiles hit the Alien it'll actually be stunned. So it needs to get close enough to receive a good hit.

The Alien doesn't simply ignore the Cattleprod but notice it, turn around and kill you. That's wrong too. Tested that with a flare inspecting Alien and a Cattleprod to the ass. The special thing about this weapon however is that it can silently insta-kill humans - the only silent weapon in the game.

The Maintenance Jack can also be used well against Facehuggers, as the weapon auto-targets them and kills them in 1 hit, but also causes minor damage to the player because of their acid blood. This is useful information when you want to safe flamethrower ammo vs these.

The molotovs should be avoided, as pipe bombs are better allrounders, unless you have excess materials to craft these. Smoke bombs are vastly underrated. EMPs are largely useless as they only affect regular Working Joes but not the industrial ones, not the humans, not the Alien and there aren't any station systems that can be (temporarily) disabled by these.