Strategy:Arachnotron

Main Guide (v0.9.9.5)

Version Changes (v0.9.9.6)

Nothing significant to the enemy itself.

General Tactics

Base strategy posted by IronBeer 19:02, January 27 2012 (GMT).

The Arachnotron is a ranged attacker, equipped with a lowish-power (1d5x5) but somewhat accurate (+3) plasma gun. Even in the best circumstances, fighting a ‘tron in an open area is a hairy proposition, but a straight-up gunfight is seriously complicated by an Arachnotron’s 130% speed. This essentially means that an Arachnotron will get to make (assuming normal move/act speeds for the player) 4 actions for every 3 of your actions. Generally, these actions will be to fire upon the player should s/he be in view, and those extra actions have a nasty tendency to appear at the exact worst times.

Arachnotrons are fairly durable with 50 hitpoints and 2 points of protection, so fairly heavy firepower is necessary to bring one down efficiently. However, their high speed results in an enemy that can lay down a very heavy field of fire. Circle-strafing or side-stepping is somewhat effective, but two factors work against the player who attempts this. First, the sheer number of shots an Arachnotron fires mean that at least a few will hit you eventually; second, Arachnotrons are frighteningly good at getting their extra action while firing on the player. This extra action essentially means that the Arachnotron will get a free cheap shot on a “stationary” player, since the player did not move immediately prior to the Arachnotron’s last move. (See Dodging.) Needless to say, this is very bad for the player.

Now that we know what we’re up against, how do we go about killing these things? As noted above, Arachnotrons are pretty tough, so we’ll probably need a few actions to bring one down. The threat of being counter-attacked should always loom large, so most of our tactics should generally involve firing such that our foe cannot retaliate.

Weapon Usage

Early-game (Hell’s Armory, ordinary floors at higher difficulty levels), your best bet is some flavor of shotgun and corner-shooting. Shotguns serve very well by permitting the player to attack blindly, and by knocking back the Arachnotron, forcing it to spend an action getting back into position. Knockback can also sometimes be used to push an Arachnotron into acid or lava, killing it more quickly, but often destroying their plasma cells in the process. If an Arachnotron is dumb enough to close into melee range while you have a shotgun equipped, you should think twice before firing at point-blank range. If the ‘tron is badly injured, and you’re certain that your next blast will kill it, then go ahead and fire. Alternatively, if the ‘tron is against a wall and won’t be knocked back, go to town- this particular foe is weak in melee. However, if the Arachnotron is fairly healthy and has a space to be knocked into, you may want to switch weapons- the danger is that you’ll knock the ‘tron out of melee range and it’ll melt you with easy short-range fire on a stationary target.

I generally don’t endorse using rapid-fire weapons against ‘trons unless your build really takes advantage of them. A chaingun in untrained hands will be a difficult and painful gunfight; a plasma rifle should do a bit better owing to the increased damage and armor reduction, but it’ll still be messy. Any rapid-fire master trait (especially Ammochain) lets a player go just about toe-to-toe with a ‘tron, generally by wasting the ‘tron first. Blind-firing into a known position is a fully viable strategy, but may be expensive, ammo-wise. Staying out of an Arachnotron’s sights is generally worth the ammo investment, and plasma users might be able to break even.

An unmodified rocket launcher is a rather poor choice for slaying ‘trons, but pretty much any practical mod setup or special rocket launcher is quite effective. A non-exhaustive list of “good” mod setups would include: 1 bulk mod, a micro launcher, or a tactical rocket launcher. Alternatively, a couple levels in Reloader will work; off-setting that slow reload time is crucial to using rockets against Arachnotrons. Since they already have the potential to double-act, the base reload time only makes that problem worse should you choose to reload at a bad time. Actually fighting Arachnotrons with rockets is pretty simple: check range, aim, shoot, reload and repeat. Rockets should usually deal knockback, and an Arachnotron engaged at the edge of viewing range should seldom retaliate effectively, if at all. 3 rockets will usually do the job, but will destroy the plasma cell drop.

The BFG 9000 is OVERKILL, and if you’re pointing one at an Arachnotron, it better have a lot of nearby ugly friends, or you better be sitting on a trainload of extra cells. The same problem with the rocket launcher (reload time) is also an issue for BFGs.

The last engagement option is to get up close and bash an Arachnotron’s ugly face in with a melee weapon. Surprisingly, this is a pretty good idea: Arachnotrons have -100% (yes, that is a negative) resistance to melee damage. Anybody can easily dispatch a ‘tron with a chainsaw, and a trained Brute can punch one out with little trouble. Arachnotrons can hit back for moderate damage, but it is a lot less than their ranged attack. Of course, the only problem is getting close.

• If you find yourself a couple of spaces away from an arachnotron with no cover immediately available, charging into melee range is probably your best option (running mode not necessary, in my opinion). Another way to get them into melee range is to just wait around a corner and shoot them to get their attention, and wait. Charging into melee towards an arachnotron at the edge of your vision is just asking for trouble though: you'll be taking plasma volleys, and in general charging into melee exposes you to fire from other enemies, especially ones that were out of sight behind the one you're after. Matt_S 00:24, February 02 2012 (GMT)

Also, switching to your best armor is seldom a bad idea, just in case. This usually means red armor, or something with Plasma resist (if you’ve gotten lucky).

Trait Usage

Defensive traits such as Ironman and Tough as Nails don’t exactly shine against Arachnotrons, but the extra tankiness is the unsung hero that will keep you alive during a firefight. I typically take Ironman after getting a master trait on just about every build I do. Brute can be valuable as well, but charging an Arachnotron just for the sake of getting a melee kill is a bad idea; baiting a ‘tron into chasing you can simplify the “closing-in” problem, but you may take some hits. Dodgemaster is actually less helpful than you would think, since Arachnotrons attack in bursts, and the trait only affects the first dodge per incoming attack. Rank 2 in Intuition is always good, perhaps even too good- the application should be pretty obvious. Gun Kata has the potential to ruin Arachnotrons so long as your pistols have the capacity to kill your target in one clip. Ammochain is a time-tested classic trait; the near-zero ammo consumption combined with a well-modded weapon allows a player to easily outshoot ‘trons. If you’ve managed to get a really good suit of armor Survivalist has the potential to be absolutely hilarious and can totally negate an incoming volley.

Miscellaneous Information

Arachnotron Caves are fiendish levels that have ended many a game for unfortunate Doomguys everywhere. They're seldom simple, and a lot of times your best bet is to simply try and bolt for the stairs or pop a homing phase device. If you feel confident in your gear and your supplies, clearing the cave presents both challenge and opportunity. The challenges lie in the fact that caves combine huge open areas with lots of blind corners. Radar shoot where possible and try and stay behind cover if using shotguns. There are positions where you can see your target but they cannot see you (and thus cannot retaliate); these positions are not intuitive or easy to communicate, but can be figured out over time. If using a well-kitted rocket launcher (or derivative), try to isolate and snipe ‘trons individually just as they enter vision. This is often easier said than done, but a Missile Launcher really helps. Rapid-fire gunners should simply try and stay in cover and poke at Arachnotrons when they wander into view; gunners typically have the firepower to quickly dispatch ‘trons but nobody can really afford to get shot up. Of course, the opportunity presented is the pile of power cells that the Arachnotrons will drop, and occasionally loot and powerups on the floor.

• This is a time where I'd recommend activating run mode if there's any Arachnotrons around you. Hurry behind any group of rocks you see, and if you have a rocket launcher or even a BFG, this is a good time to bring it out. A melee weapon can actually be really useful here, as there will often be situations where an Arachnotron comes sneaking around the corner of your rock cover, where he's too close to blow up (except with a BFG which doesn't hurt you) and where you can't corner shoot him with a shotgun. Matt_S 00:24, February 02 2012 (GMT)
• I thought this info might be helpful, which shows the minimum depth and number of Arachnotrons in a cave. More Arachnotrons will appear if playing Ao100: number is dependent on depth. Shark20061 09:26, 7 March 2012 (CET)

Regarding powerups: Do not even think about taking small health globes if you're under enemy fire. Since they restore you from running to normal, Arachnotrons will get a "temporary" restoration of their accuracy, from +1 all the way to +5, which is a huge difference at any range: the end result is that you'll lose much more than you could gain. Taking large health globes is safer against a single at-the-edge Arachnotron, but even that can be more dangerous than it's worth. Same thing about using med-packs - beware of using them without cover: being Technician in this case is a great help, as you can switch to running back after only 0.1s instead. Berserk Packs are mostly a shoe-in, but against arachnotrons it's not as effective as usual as each hit will deal at least 1 damage anyway.If you don't see stairs or a particularly nice powerup (like the Invulnerability Globe), run to cover. AlterAsc 15:34, February 03 2012 (GMT)