XCOM 2 Gear Analysis: Weapon Attachments
Weapon Attachments are like PCSes, but for (primary) weapons; you primarily loot them from the battlefield, they come in Basic/Advanced/Superior tiers, they can be bought at the Black Market, by default if you replace an attachment you lose the previous one... but there's some differences.
First of all, weapons can have up to three Weapon Attachments. At the beginning of the game you can only install one per weapon, but advancing your weapons technology will open up a second slot, while the third slot depends on which version of the game you're playing; in the base game, you can roll a Continent Bonus that adds a Weapon Attachment slot to all your weapons, while in War of the Chosen you instead add the additional slot via Breakthroughs, with each Breakthrough applying to a specific weapon class. (ie Shotgun, Assault Rifle, Sniper Rifle, Cannon, Vektor Rifle, or Bullpup. Unfortunately, SPARK autocannons don't get in on the action and are stuck with 2 slots forever) This means you can stack Attachments to an extent, though note that you're not allowed to attach multiple copies of the same kind of Attachment. They have to be three different Attachments.
Second, Weapon Attachments are attached to a given weapon, not to a soldier. You can customize one soldier's weapon, then have them out of action for a month from wounds, shrug, and simply pass the weapon off to someone else. A related point is that if a soldier dies, you only lose the modified weapon if you don't manage to retrieve the body, contrasting with PCSes where a dead soldier takes their PCS to the grave no matter what.
Third, Integrated Warfare doesn't apply to Weapon Attachments, and in fact in the base game there's no way to boost them at all. In War of the Chosen you can boost them via a continent bonus or a Resistance Order, but even then it works differently from PCSes; where PCSes used percentage boosts except on Conditioning and Speed (Because their values were too small to make them percentile), Weapon Attachments being boosted effectively 'levels up' a given tier to provide the effects normally provided by the tier above, with Superior extending this to a hypothetical fourth tier. As such, in the following stuff I only specifically bother to list 'Boosted Superior' as its own value; to find out what Basic does once boosted, just look at Advanced, and to find out what Advanced does when boosted, just look at Superior. Simple.
Fourth, where PCSes require the Guerrilla Tactics School be built before you can use them, Weapon Attachments instead require you research Modular Weapons before you can mess around them. Like with PCSes this is a bit pointless, particularly in the base game: Modular Weapons takes barely any time at all, you don't actually have particularly higher priorities, and it's a prerequisite to researching Magnetic Weapons, which you're going to want researched relatively early in a run, before the game starts punishing you for falling behind the curve. In War of the Chosen Inspirations and Breakthroughs might cause you to delay it long enough to actually matter, but in the base game it's confusingly pointless, and War of the Chosen still doesn't have purpose behind it.
Note that the game is kind when it comes to Weapon Attachments interacting with raising weapon tier. Purchasing a higher tier of weapon will cause all weapons of that category with Weapon Attachments to switch to the new tier; you shouldn't hoard early Weapon Attachments on the idea that you'd be wasting them on Conventional weapons you'll soon replace. No, your Conventional Cannon with a Scope on it will become a Magnetic Cannon with a Scope on it.
Also note that Templar actually can't use Weapon Attachments at all; you're only allowed to apply them to a unit's primary weapon, and the Templar's primary weapon is a melee weapon, which wouldn't even make sense to benefit from much of any of these in mechanical terms, let alone conceptual terms. (eg Gauntlets don't have ammunition, and so Auto-loaders and Expanded Magazines have no relevance to them anyway)
On a different note, I'm not doing images for the Weapon Attachments, as they use different images for different weapons and different tiers and it would just clutter things or force me to pick one weapon type and tier's images to represent the Weapon Attachments. Bonus points: Scopes and Laser Sights use the same icons anyway!
Honestly, I'm a bit frustrated at how much graphical effort went into Weapon Attachments, as it's a poor return on the investment. (Each Attachment has a graphic for each weapon you can apply them to, multiplied by all three tiers: that's 147 different graphics in War of the Chosen, considering SPARKs! Just weapon models, not counting the highlighting effect used to represent Weapon Attachments or the menu icons!) The game outright has Attachments on the actual weapon models, which is essentially invisible 99% of the time (Even when the camera zooms onto an individual soldier, good luck noticing a given Weapon Attachment), making the entire system pretty pointless to have put so much effort into the visual end of things. I really wish they'd just had standard inventory icons to represent the concepts and not bothered with having the weapon model change at all; basically the only time you can notice the difference is when you're in the Avenger, fiddling with a soldier's gear. And honestly the Weapon Attachments are often sufficiently subtle they don't even act as a quick way to check what your currently-lined-up soldiers have in their gear: you're still forced to manually check them, realistically speaking, negating one possible use for them.
Oh, and note that the game refers to them as 'weapon upgrades'. I'm not using that terminology because it's unnecessarily confusing given you can also describe purchasing a Magnetic or Beam-tier weapon as upgrading your weapons, and in general 'upgrades' in a video game of this general format is usually referring to permanent improvements to all versions of a given whatever, which Weapon Attachments most certainly are not.
Boosts the weapon's Aim. Against targets not in Cover, provides 5 more Aim beyond the below values. Cannot be combined with a Laser Sight.
Boosted Superior: +20
Design-wise, I really like Scopes.
One of the biggest reasons losing elite soldiers is harmful in any game cleaving to classic X-COM's mold is that it doesn't matter how powerful the gun your rookies are wielding if they can't actually hit the target with it. Indeed, in classic X-COM more powerful weapons can directly contribute to things going wrong, as a Heavy Plasma shot going sideways is pretty much guaranteed to instantly kill whatever unfortunate soldier catches it with their face, where a conventional rifle shot would actually have serviceable odds of being non-lethal. Since technological improvement doesn't bring accuracy improvements in classic X-COM, this is a perpetual problem with losing elite soldiers.
The prior game did have the SCOPE and more subtly the fact that advancing your armor technology provided options for more readily reaching high ground, but the SCOPE was actually an early game piece of equipment that never had its Aim bonus go up and inevitably suffered from competing with other Item slots -yeah, Snipers always carried a Scope, but for other classes it was often more useful to carry a grenade. Why get +10 Aim when you could smash the enemy's Cover to effectively grant your entire squad +20 or +40 Aim while also doing damage to the enemy? Armor, meanwhile, only had one significant late-game innovation in this regard, that being Archangel Armor opening up the possibility of getting the high ground Aim bonus even in flat maps.
The overall result was that having a large chunk of your squad killed -or even just put in the hospital for a long time- could lead to fresh-faced Squaddies who don't know the front end of the gun from the back end turning what should be an easy mission into a catastrophe because they just can't hit anything, particularly since the prior game believed in the Red Queen Effect when it came to Aim vs Defense, where later enemies consistently all unavoidably had more Defense, such that a Squaddie with endgame gear actually had a harder time hitting their enemies than a beginning-of-game Rookie did hitting their own enemies.
XCOM 2's Scope, meanwhile, helps sidestep this issue. Even Sharpshooters and Reapers only gain 26 Aim from leveling, and notably the first 10 points are gained at Squaddie, which Reapers outright start at and a Rookie can be forced to be a Squaddie Sharpshooter via the Guerrilla Tactics School, so really you might as well say they only gain 16 Aim from leveling when talking from the perspective of getting a soldier up to speed in the mid-to-late game. (eg because your best Sharpshooter died, and you're training up a replacement) That means the difference between an elite, highly accurate soldier and a luckless Squaddie passed the old guard's stuff when they died gloriously for the cause is actually not much, and in fact a Squaddie Sharpshooter with a Superior Scope will have more accuracy against targets in the open than a Colonel Sharpshooter with no Scope at all.
This makes your squad a little more resistant to casualties, making it easier to bounce back when things go wrong. It's also important to note here that XCOM 2 does not believe in Red Queening Defense with Aim; while it's true that, for example, ADVENT Troopers and Officers pick up 10 Defense when they hit Elite, and that all the innately high-Defense enemies are placed late in the game, the game doesn't just keep raising the bar in tandem with expecting your Aim to climb. Mutons are an early-midgame enemy, and they already have 10 Defense: 10 Defense becomes pretty widespread in the late game, but there's nothing comparable to how in the prior game Muton Elites have 30 innate Defense while still getting to use Full Cover.
The massive reduction in Red Queening means that passing out and improving Scopes has a fairly concrete benefit. Once you hit a threshold of being able to achieve 100% hit chances on 10 Defense enemies in X, Y, or Z conditions, that stays a relevant and useful bar to have hit all the way into the endgame.
This is great stuff, and the closest thing to a complaint I have is that Scopes are attached to the Weapon Attachment system, while being vastly more vital an effect than any other Weapon Attachment's benefits. These design benefits are somewhat undermined by the fact that you can't actually attach a Scope to literally every soldier's weapon without making some manner of sacrifice. Not fatally so, but enough so that I suspect the devs were thinking of Scopes as a customization tool rather than as a way of making elite units not so dominatingly necessary, which would be a bit unfortunate, particularly if it means that XCOM 3 abandons that benefit entirely from not recognizing it exists.
Before getting into class stuff, it's worth mentioning that the Scope's bonus +5 Aim isn't based on whether the target is getting a Cover bonus or not. Enemies that don't use Cover that are nonetheless standing adjacent to relevant Cover will not let you get that bonus +5 Aim. This is not communicated at all by the game itself -in fact, it doesn't allude to this +5 bonus at all, anywhere- and can lead to confusing situations where eg two Chryssalids are standing close together and you find that you have more accuracy against the farther of the two. As such, you may wish to pursue 'flanks' against units that doesn't otherwise apply as a concept to, or open with Cover-smashing mechanisms like grenades before taking the shot, so your 96% chance to hit pops up to a perfect 100%.
Scopes are generally least important to Rangers; proper Shotgun use makes additional Aim bonuses a bit redundant (A Squaddie Ranger can get to 108 Aim just by getting up next to the target. A Colonel can potentially be perfectly accurate firing through Low Cover just by being in the enemy's face, or Rapid Firing on a flank with no miss chance), and no the Scope doesn't boost their melee accuracy.
Silent Killer Reapers are also generally inclined to skip a Scope; skulking around in the shadows, grabbing flanks from hilariously close range is often plenty enough for reliable shots, since they have the same level-based Aim progression as a Sharpshooter but then they can get up to +25/26/27 accuracy from getting up close.
For basically everyone else, Scopes are one of the more consistently desirable Weapon Attachments, and it's very much a question of personal priorities as far as who gets them and who attaches them before other attachments. Sharpshooters love to extend their effective Squadsight range, as well as appreciating being able to push their Aim high enough to potentially shrug off Low Cover. Skirmishers desperately need more Aim anytime they're shooting at a distance, but can also get by without Scopes and really desperately need ammo support. Specialists have mediocre Aim and Guardian can't trigger on misses, but they can also lean heavily into non-shooting abilities. Grenadiers have bad Aim and Shredder and Chain Shot don't do anything on a miss, but a grenade-lane-focused Grenadier can treat hitting more as a bonus than anything else and even a gun-play-oriented Grenadier can break out Hail of Bullets when it's vitally important to hit.
SPARKs, in War of the Chosen, very much appreciate a Scope to make up for their inability to equip other Aim boosters and less-than-ideal maximum Aim. A Champion SPARK normally ends up at 85 Aim, which means even if you assume high ground or a point-blank shot there are, in the endgame, a lot of enemies you'll still have a miss chance against due to innate Defense, even if they aren't taking Cover. (eg Chryssalids, which have 10 Defense and don't ever use Cover) A Superior Scope pushes them up to the point that high ground will let them ignore Low Cover on 0-Defense targets, as well as ensure having a little innate Defense doesn't force a miss chance, not to mention make it less vitally important to constantly abuse their superior ability to reach high ground. The main question is if you can justify fitting in the Scope, since an Expanded Magazine is basically mandatory and an Auto-loader is preferred as well, at which point you don't have room for a Scope. Still, you can get away with skipping an Auto-loader if you prefer a Scope, so it's certainly an option.
So like I said: everybody wants a Scope aside Rangers and Reapers (And Templar, but if they could put them on Autopistols they would) and it's pretty firmly a question of priorities.
Boosts the weapon's crit chance. Has a secondary boost that climbs as the soldier gets closer to the target, to a maximum of +10 beyond the general bonus. Cannot be combined with a Scope.
Boosted Superior: +20
The Laser Sight is pretty much custom-made for Shotguns. Able to gain up to 40 Aim just from getting closer to the enemy and exclusive to a class particularly effective at flanking enemies, the conflict with a Scope is meh, meanwhile the greater crit chance for getting closer is rewarding you for doing what you were going to do anyway. And of course Shotguns get huge crit damage -slightly less so for Storm Guns in War of the Chosen, but it's still a lot.
For any other weapon, it's a harder sell. Not impossible, but harder. Reapers are a notable option for potentially favoring the Laser Sight, if you're good at sneaking them around among enemies without being spotted, since at that point additional Aim isn't very important anyway, but on the other hand if you're doing sneaking-shooting that's ideally Silent Killer-backed and that doesn't play nice with relying on crits. On the third hand, Laser Sights are completely worthless to Banish, so if you're focused on Banish you should go for a Repeater or Scope instead, after an Expanded Magazine.
You might intuitively expect Bullpups to be a good choice for Laser Sights, since they're a close-range weapon and Skirmishers are pretty good at arranging close-range clean shots, but Bullpups get terrible damage out of crits. Pretty much anything else is going to be a better use of the slot.
While I personally generally prioritize a Scope due to Specialist's not-great Aim and Overwatch penalizing Aim further, once you have Cool Under Pressure purchased there's a decent argument for considering a Laser Sight on a Specialist's Rifle, particularly if they either have a Superior Perception PCS or you've boosted their Aim via Covert Ops in War of the Chosen such that further Aim boosts are a bit overkill. For other classes, the Laser Sight is held back a little by doing nothing in Overwatch (Not counting Overwatch ambushes), where for Specialists it's an always-on benefit, and boosting their crit chance is effectively a boost to their otherwise somewhat-substandard damage.
Laser Sights aren't specifically bad for Grenadier Cannons, but tend to be a poor choice except as filler. Literally every other Weapon Attachment is a stronger fit: Expanded Magazines and Auto-Loaders make up for how ammo-hungry a Grenadier can be, Scopes make up for the Grenadier's poor innate Aim and makes more viable eg Chain Shot, Repeaters fit naturally to the fact that they tend to be the first soldier to take a shot against tough targets, and Hair Triggers being versatile is an excellent fit to their access to a wide variety of good active shooting abilities.
Psi Operatives don't particularly directly discourage giving them Laser Sights, but they don't particularly encourage it either. They really shouldn't be shooting that often anyway.
Sharpshooters would actually be a pretty good choice for giving a Laser Sight... if only they didn't conflict with Scopes. Particularly if you want to actually take advantage of Squadsight, Sharpshooters have a deep need for more Aim on their Sniper Rifle shots, making it difficult to justify not including a Scope.
For SPARKs, Laser Sights aren't bad, exactly, but they're not particularly good; every other Weapon Attachment is probably more useful to a SPARK in real terms. You might give them a Laser Sight early in the game for lack of options, but it's probably not going to be a part of their endgame kit.
Design-wise, Laser Sights are unfortunately not very purposeful. Specializing in crit chance isn't really a meaningful niche, and crit chance numbers are carefully tuned so you can only hit 100% crit chance on flanked targets, so even on weapons whose damage is biased heavily toward crits you're going to end up unreliable against unflankable targets... which are pretty consistently the toughest targets you most desperately want bonus damage on.
They're also a continuation of the prior gaming making one of the bigger payoffs to flanking being crits and yet letting you pursue crits without having to flank, though it's overall less egregious in XCOM 2 in part simply because crits aren't nearly so dramatic a spike in damage in most cases, shifting the balance of flank benefits more heavily toward the Defense-bypassing aspect.
They're inoffensive in their not-great-design, but Laser Sights aren't very well considered, overall.
Successful shots have a percent chance of instantly killing the target.
Boosted Superior: +20%
Design-wise, the Repeater is by far my least favorite Weapon Attachment type in the game.
In the base game, with absolutely no DLC, Repeaters are largely worthless. The game is tuned so that even on Legendary you expect to kill the majority of enemies in 1-2 successful hits if you're keeping up with your weapons technology. As a concrete example, toward the very beginning of the game you're mostly fighting basic ADVENT Troopers, with the occasional Sectoid or Officer acting as a squad leader; even on Legendary, ADVENT Troopers always die to a hit from Cannons, Sniper Rifles, and Shotguns, and even with Rifles they still die 2/3rds of the time if we ignore the possibility of crits raising those odds. Legendary ADVENT Officers only have 7 HP: any two hits from a base-game primary weapon will kill them unless both shots are specifically Rifles, in which case they have to both get their 1-in-3 chance of minimum damage for it to not be a kill. (ie a 1-in-9 event, less if crit chance is involved) Only Sectoids of that bunch have enough HP to have reasonable odds to survive being hit twice; 10 HP, which means that non-Rifles can roll minimum damage once and middle damage once or minimum damage twice to let them live, while Rifles can even roll minimum damage three times to let them survive three whole shots.
In a typical early game mission, you'll have three pods of two: one pod will be two ADVENT Troopers, one will be an ADVENT Trooper and a Sectoid, and one will be an ADVENT Trooper and an ADVENT Officer. ie 2/3rds of those enemies a Repeater is worthless on a non-Rifle, one of those enemies a Repeater might save you a shot, and one of them you might even save two shots.
While the exact numbers change as you get deeper into the game, this spread is still pretty representative of your hit-to-kill needs for a decently large portion of the game. Eventually, very late in the game, you tend to expect to need two successful shots to kill a 'grunt' enemy like an Elite Trooper, but that's only if you look at basic numbers; in the base game, a Ranger with a Storm Gun flanking an Elite Trooper will do 11-13 damage even without a crit thanks to Hunter's Instincts. Elite Troopers only have 11 HP on Legendary, and no, they don't have any Armor. War of the Chosen nerfing Hunter's Instincts means the Ranger needs a high roll or a crit to one-hit-kill an Elite Trooper on Legendary with a Storm Gun, but a crit is worth +4 damage and a Ranger can outright hit a 100% crit chance in those kinds of conditions, still ensuring the kill.
ie even in the endgame, you frequently expect to one-hit-kill common enemies. The main thing that changes is that you largely stop seeing pods that are made only of Troopers, meaning a pod will almost always have an enemy that will probably survive at least one hit. You know, assuming nothing is going on like it's a Codex and you've got Bluescreen Rounds, or it's an Elite Shieldbearer but the attacker has AP Rounds, or any other advantageous factors to push things over into one-hit-kill territory.
So where do Repeaters have value in the base-base game?
Well, once you're in the endgame with Sectopods, Gatekeepers, and Andromedons, a mission can have 1-2 of some mix of those enemies, and they're all tough enough it's largely unrealistic to one-hit-kill them. A Legendary Andromedon has 21 HP and 4 Armor: even if I assume a Ranger who is critting and carrying AP Rounds to completely ignore the Armor, they'll only do 16-18 damage on an individual shot. (Mind, they have Rapid Fire...) Gatekeepers and Sectopods are even more ridiculous, with enough Armor AP Rounds isn't enough to completely ignore it and around 30 HP on Legendary, and as far as using a Ranger as the baseline goes they're not susceptible to Hunter's Instincts, meaning even an AP Rounds Rapid Fire that was critting on both hits would only do 24-26 damage to a Sectopod, and 22-24 damage to a Gatekeeper -not enough to kill them under these actually over-generous assumptions.
First of all, Sectopods and Gatekeepers are both susceptible to Bluescreen Rounds. A Fan Fire Sharpshooter supported by some Shred can casually annihilate them, doing 24-33 damage on the Fan Fire alone if the Armor is already gone and they have Bluescreen Rounds. Saving ammunition isn't a consideration since Pistols don't have ammo limitations in the first place, and Fan Fire isn't exactly needed against most targets, so avoiding using it on a Sectopod or Gatekeeper doesn't matter by letting you use it against a different pod unless you pretty much immediately run into another Sectopod or Gatekeeper.
Second of all, the rarity of these enemies in general, and the way the game controls the pacing of pod encounters, means that good play can easily afford to blow resources on killing them without any real possibility of it backfiring. A Repeater killing one of these enemies early is funny and all, but unless things are going disastrously it's probably not meaningfully helping.
And even if it were, the Repeater's chances to trigger are simply too low. A run that doesn't deliberately dawdle is actually unlikely to encounter more than maybe three Sectopods across the entire run prior to the final mission, and Gatekeepers take even longer to enter rotation -I've had runs finish quick enough that the only Gatekeepers I encountered at all were plot-mandated ones. Generously call that 10 Big Targets across the run, and a Superior Repeater expects to help once or twice if you have it on one soldier and also assume they were always taking a non-lethal shot anyway.
Andromedons are a slight boost to the Repeater's relevancy: they're harder to trivialize (There's no Bluescreen Rounds-esque mega-boost to make it easy to take them apart), they're notably more common (They tend to show up two in a mission when they first enter rotation, where Gatekeepers and Sectopods start out generally only being one or the other on a map and only later start having one of each or two of one, and Andromedons enter rotation notably sooner), and they're tough enough that a Repeater trigger probably is saving you effort. Their commonality also means that it's a little harder to justify blowing Heavy Weapons, grenades, or limited-use abilities on them; maybe you blow half your limited-use stuff on one Andromedon, then half on another, and then encounter a Sectopod and realize you already threw away everything that would make it possible to one-round it. Oops. Better to use your reusable resources on Andromedons as a result.
Still... what this all boils down to is that in the base-base game, Repeaters are extremely narrow in their application. At the beginning of the game they're nearly useless, even aside how low the odds of a basic Repeater triggering is, so much so you probably ought to just sell Repeaters you find unless you luck into an early Superior Repeater. Toward the end of the game when there's finally enemies a Repeater triggering can be useful against, the list of enemies they can meaningfully help against is still frustratingly narrow.
As a final nail in the coffin, they compete with other Weapon Attachments. Sharpshooters don't really want them because they ideally don't use their Sniper Rifle that often anyway and also ideally focus on sure-kill shots when they do use their Sniper Rifle -and no, Kill Zone doesn't save the day, because Repeaters can't trigger on Kill Zone shots. Rangers don't really want them because they also ideally go for sure-kill attacks, and other Weapon Attachments much more reliably help them assure such. Grenadiers are okay with them, and indeed are arguably the best choice for a Repeater since a Grenadier should normally be your first soldier to take a shot at a healthy Armored target to clear out its Armor, but they also desperately need ammo support and will really appreciate a Scope as well; that's two of your guaranteed slots already taken, and if you get the third slot unlocked an argument can be made that it makes more sense to stack on both ammo-supporting Attachments. And of course Psi Operatives don't care that much about their gun and SPARKs, in the base game, can't equip Weapon Attachments, making the question moot for them. Specialists really want ammo -to support Guardian shenanigans- and Aim -so they'll actually hit things in spite of their dubious Aim and poor ability to compensate for it with flanks and whatnot. If they have a third slot available, a Repeater is a reasonably decent third choice, but otherwise it'll tend to be pushed aside.
In short: in the base-base game, Repeaters don't fill a coherent niche.
When DLC gets involved, it's another story, but I actually dislike how DLC affects Repeaters more than I dislike them lacking a place in the base game. Against Alien Rulers, Julian the Prototype Sectopod, and the Chosen, Repeaters are dumb gamebreakers; these are all foes that are very durable, and in the case of the Chosen and Alien Rulers you fight them repeatedly over the course of the game, where they're all designed around the idea that you are going to need to wear them down over multiple turns to kill them. And then you lolrandomly skip that entire thing with a lucky Repeater trigger, turning them into free Ability Points.
Like yeah, this gives Repeaters a place: they're your Attachment of choice when you expect to fight a 'boss' enemy. But that place is a gamebreaking bit of nonsense design, not an interesting and valid niche. As a bonus, all these boss enemies fall to the wayside: the Alien Rulers inevitably die and never come back, Julian is a one-time encounter if you even have his mission turned on at all, and you're intended to hunt down and kill the Chosen before launching the final mission. This means Repeaters fall away in relevance in the endgame -and due to other changes War of the Chosen makes, the endgame enemies most favorable to Repeaters are vastly less favorable to Repeaters than in the base game. Why fish for a Repeater kill on a Sectopod when a Darkclaw-bearing Sharpshooter can take Bluescreen Rounds to Fan Fire for 24-33 damage when you haven't bothered to Shred the Sectopod? Oh, and maybe your run has a Beam Weapons Breakthrough and a Pistol Breakthrough; whoops, now you're doing 30-39 damage, ensuring the kill without any help at all. At that point, fishing for a Repeater kill might break even, but will usually put you behind on action economy!
Similarly, War of the Chosen has actually exacerbated the Attachment crunch, as instead of a single Continent Bonus giving all your weapons a third slot, you get Breakthroughs that individually add Attachments to specific weapons, drastically lowering the odds that any given type of soldier you'd be most willing to put Repeaters on for the third slot will get that opportunity.
This isn't even getting into the more general point that this kind of low-odds randomness is almost always bad for this kind of game. Normally I would've opened with complaining about this, but it's completely overshadowed by all the other reasons Repeaters are a terrible fit for the game.
I really feel like a base damage boost would've made more sense than the Repeater's effects, as far as a 'damage enhancement' effect. I can see arguments for how that would be problematically centralizing, but I really feel that would be less bad for the design than this.
All that said, I already went over the classes in the context of the base game, but it's worth mentioning that in War of the Chosen a Repeater is actually a decent choice for a Skirmisher if you luck into Bullpups getting a third slot; Skirmishers have a lot of tools for getting extremely accurate shots such that a Scope can be skipped without necessarily being a problem, the damage boost they get from crits is utter garbage so even though a Laser Sight seems a natural fit for them they don't actually get much benefit from one, Stocks are useless if you're always arranging those highly accurate shots, while Hair Triggers having superior flexibility isn't particularly helpful against the tough targets Repeaters are best against. So equip an Expanded Magazine and an Auto-Loader, and Repeaters are arguably the best third slot.
Similarly, if you go for Annihilate on a Reaper, a Repeater isn't a bad choice after an Expanded Magazine. You'll be taking so many shots a Superior Repeater actually expects to trigger at some point in the chain, and your Reaper will smoothly transition to their next target. In a stupendously bad situation where you accidentally pulled three pods outright, this could be a lifesaver. Even without Annihilate, if you like to use Banish to deal with Chosen and Alien Rulers, a Superior Repeater has something like a 72%~ chance to trigger once across six hits, which is pretty darn good odds, and could help a lot on Legendary where Chosen are almost impossible to kill in a single turn without a Repeater trigger.
Lastly, SPARKs aren't a completely awful choice for Repeaters, especially if you take Hunter Protocol. A SPARK, like a Grenadier, should usually take your first shots to wipe out Armor, and between Overdrive and Hunter Protocol they'll make a disproportionate number of shots at enemies, with Hunter Protocol in particular biasing them toward being the first to make a shot. I might even say it was their best choice for a third slot if only that was an actual option for them. As-is, they unfortunately suffer from the fact that they've only got two slots and pretty much must have an Expanded Magazine. As an Auto-loader and Scope are both excellent choices for the second slot, it's still pretty difficult to justify a Repeater. Maybe slot one in if you're short on Auto-Loaders and Scopes in general on the assumption you'll replace it later.
Firing a standard shot with the weapon has a percent chance of refunding the entirety of the soldier's current action points, assuming the shot hits.
Boosted Superior: 20%
It's tempting to think of the Hair Trigger as a nice general upgrade that merely happens to be tied to RNG. In actuality it's largely inferior to a Repeater; the Repeater can trigger on Overwatch shots as well as most if not all special shooting shooting actions (Where Hair Triggers can only trigger on some of the 'basically a regular shot' ones like Deadeye), and against tougher targets a single Repeater trigger can easily be worth multiple Hair Trigger activations. (That is, instant-killing a Sectopod that would've taken another five shots to kill is clearly superior to having Hair Trigger let you get a single bonus shot on it) The unfortunate thing is that they have the same activation chance, and therefore there is no possibility of arguing a Hair Trigger can justify itself on the basis of a greater activation chance, beyond the local situation of 'would I rather give this gun a Basic Repeater or a Superior Hair Trigger?' (Yes, Hair Triggers can activate on misses and Repeaters can't, but you don't tend to miss on non-Overwatch shots, making it usually a moot point)
However, while the Hair Trigger is pretty niche compared to the Repeater, it has a pretty strong argument for what niches it has. A Silent Killer Reaper would much rather have a Hair Trigger than a Repeater, for example, since they're going to be trying to pick off weakened targets the Repeater adds nothing against anyway. Less strongly, a Death From Above Sharpshooter overall prefers the Hair Trigger to the Repeater, since they're biased to finishing shots that the Repeater won't do anything on, whereas having a Hair Trigger go off can potentially allow the Sharpshooter to eg kill a target, get lucky on Hair Trigger, kill another target, and then reload/Hunker Down/re-position/whatever they were planning on using the Death From Above action on anyway.
Rangers are a more subtle example, specifically once they have Implacable and/or Untouchable, as those both bias them toward pursuing kill shots anyway, making a Hair Trigger more relevant than a Repeater. Notably, Shotguns aren't strongly motivated toward other Weapon Attachments; Scopes are redundant, Stocks make no sense if you're consistently hurling your Ranger into the fray where misses aren't an issue, and both Expanded Magazines and Auto-Loaders are a bit silly to put on a melee-focused Ranger. That basically leaves you with Hair Triggers, Laser Sights, and Repeaters as good Shotgun attachments; if you're at the point you can fit three attachments to your Shotguns, might as well do all three. (Resources allowing)
In War of the Chosen, SPARKs are another good candidate for Hair Triggers over Repeaters, as an Adaptive Aim SPARK has motive to fire three times in a turn. That's enough shots in a turn it's almost reliable for higher-end Hair Triggers to activate. In conjunction with their versatility in non-shooting abilities of note, refunding actions can lead to not merely more dakka but an actual change in plans taking advantage of having 2 or 3 actions where you were expecting to have one less after shooting. The primary issue is, as I've said before, you basically need an Expanded Magazine and there's other very solid options. Still worth considering, though.
By a similar token, Skirmishers are one of the better users of Hair Triggers, since they output a lot of shooting in a turn and then have a variety of alternate ways to usefully burn action points, making bonus action points occurring as a result of shooting not nearly so 'but Repeater instantly killing a target would do the same amount of work with less ammo spent'. I rarely give them Hair Triggers in practice because I strongly prefer an Expanded Magazine+Auto-Loader, but if I get Modular Bullpups a Hair Trigger is something I give serious consideration to equipping.
A more surprising element of utility to Hair Triggers is that they're something of a counter to Alien Rulers, as a Hair Trigger activating will prevent the shot from triggering a Ruler Reaction. If you specifically set up Alien Ruler-killing gear, Hair Triggers are your best bet to add after Repeaters. Or if you hate cheesing them with Repeaters, Hair Triggers are your first choice for anti-Alien Ruler Weapon Attachment.
Design-wise, I'm not a fan of Hair Triggers. They feel like someone had a sensible idea for classic X-COM, then realized XCOM 2's mechanics don't support this idea at all, and split the difference using randomness: if you ported he Weapon Attachment system into a game that uses Time Units, a Hair Trigger would easily work as taking the current trigger chances and turning them into modifiers to the Time Unit cost, no randomness necessary. XCOM 2 only having 2 action points per turn doesn't support that level of granularity, though, so 'you shoot more often in a scalable way' gives us... rolling dice for bonus turns.
(Mind, the conversion I'm laying out wouldn't work out to quite the same thing, on average, since Hair Trigger triggers can occur multiple times in a row and a 5% cost reduction isn't, on average, quite the same thing as a 5% increase in your number of actions, but this is quibbling over details)
It's not as egregiously out of place as Repeaters, but it's still a poor fit to XCOM 2 itself.
Missed shots will do some damage to their target.
Boosted Superior: 4
Toward the beginning of the game, Stocks are very impressive, as the numbers are tuned so that it's not unusual for an enemy to survive with exactly one HP. In that case, a Stock means taking a shot is a guaranteed kill, and unlike tossing a Frag Grenade you don't have to worry about destroying loot!
Later in the game, the Stock becomes a bit more narrow in its appeal. There's the easily inferred point that it's not normal in the late game for enemies to conveniently end up with low enough HP for even a boosted Superior Stock to be a guaranteed kill. Not as obvious is Armor; it's easy to overlook when just using a basic Stock, but Stock damage is affected by Armor. It's just that Stock damage benefits from the usual rule that Armor isn't allowed to reduce damage below 1, which with a basic Stock ends up meaning Armor doesn't do anything. Your higher-grade Stocks do end up suffering from Armor becoming increasingly widespread...
... especially because Stocks don't force on-hit effects like Shred to be applied.
On the plus side, AP Rounds will actually cause Stock damage to also ignore up to 5 points of Armor, which for most purposes amounts to ensuring a miss does full Stock damage. As such, AP Rounds perform particularly well on Stock-wielding soldiers, or looking at things from the opposite direction if you have a soldier carrying AP Rounds for your own reasons a Stock is more appealing than normal.
Also easy to overlook is that the Stock's utility is highest when your soldiers' Aim is lowest. Rookies love Stocks. Colonels would generally rather have a Scope so their 80-something chance to hit pops up to more or less a guaranteed hit. XCOM 2 isn't the previous game, either; while high-Defense enemies are all relegated to the late game, XCOM 2 doesn't do the thing where enemy Defense uniformly rises such that your own climbing Aim is more or less running in place. So it really is the case that for the most part your elite late-game troops have much better odds to hit the stuff they're actually fighting than your Rookies did at the beginning of the game.
This isn't to say that Stocks are bad late in the game, just that they're not nearly as broadly amazing as their first impression might suggest. A SPARK that didn't take Adaptive Aim can appreciate a boost in viability to Overdrive bullet spam and one with Hunter Protocol expects to miss regularly period, any soldier who rolls Death From Above can appreciate the opportunity to get guaranteed kill-chains on weakened enemies, and same for Serial if you're willing to buy it. (Unfortunately, Saturation Fire and Kill Zone don't encourage Stock use, as they both are bugged and ignore Weapon Attachments and Ammo Items on the user) And of course if you just keep finding Stocks of a superior tier to anything you're finding in other Weapon Attachments, you might as well take advantage.
One consistently decent use for Stocks once you're past the early game phase of them regularly helping you ensure kills is to let you consistently break Overwatch. Take a shot: if you hit, awesome, if you miss their Overwatch still breaks, and now you're free to move other members of the squad regardless of what the RNG did.
A more esoteric use is to put Stocks on your Shotguns. This can allow Rangers to reliably contribute at least some damage even in situations where you find yourself reluctant to have them actually approach enemies for one reason or another. Particularly notable is how it synergizes nicely with Rapid Fire, potentially allowing a Ranger to do respectable long range damage in spite of atrocious hit chances. This is less notable in War of the Chosen due to Rapid Fire's long cooldown discouraging burning it on such a situation, but it's still something to keep in mind.
Skirmishers can also appreciate the Stock; Bullpups have poor enough damage on a hit that a Stock's damage isn't anywhere near as much of a downgrade as it is on most classes (A Superior Stock does half the minimum damage of a Kal-90 Bullpup, and a third of a high-roll crit: if we instead look at a Beam Cannon, a Superior Stock is just over a third the minimum damage of a hit and is less than a quarter of a high-roll crit. There's Breakthroughs to consider, but there's also Inside Knowledge's boost to Stocks to consider), they outright suffer Aim penalties for being far away, and their ability to spend every action on shooting means there's potentially a real sacrifice involved in getting closer to enemies. With a Stock, you can find yourself in a situation where two misses will definitely kill a target, making it a safe decision to stand back and open up, and in fact potentially safer than approaching to get an Aim boost on the one shot. It also makes Waylay a lot more effective once you're past the ambush phase, since later pod activations will involve the usual Overwatch penalty and likely involve the Skirmisher ending up opening fire at the edge of their range; suddenly the depressingly high odds of missing just means a modest reduction in damage, not a complete waste of ammo.
This comes with the caveat that honestly Skirmishers want (almost) all the Weapon Attachments in a way no other class does, so this is a genuinely difficult decision for them, but it's certainly worth considering.
Design-wise, I'm kinda meh on Stocks. On the one hand, I like how they're a tool for mitigating randomness without making missing impossible or irrelevant. On the other hand, the game is tuned so they fall away in relevance fairly rapidly, and it's difficult to imagine what the realistic justification for a Stock forcing damage on misses could be. They're not actively terribly-designed, but they could've and probably should've been better-constructed.
To be honest, I'd rather have seen them integrated with the Dodge mechanic. This isn't particularly compatible with the tier mechanic, but I think Stocks would work a lot better if they 'upgraded' misses into Grazes, presumably with actual Dodges downgrading them back down to being a complete miss. That would be a similar result as far as forcing damage on most targets, but one that better scales to rising weapon damage and would force on-hit effects as well, making it so Stocks would be a Grenadier's best friend; slap Dragon Rounds or Venom Rounds on them, and now you have a guaranteed way to spread Burn and Poison on most targets, too.
Still, the current version is okay, which is better than some Weapon Attachments.
Raises maximum ammo on the weapon.
Boosted Superior: +4
The Expanded Magazine is vital on anyone that burns through ammo fast. The Grenadier, Skirmisher, and War of the Chosen SPARKs are the most blatant/consistent cases, but Kill Zone Sharpshooters also want it, as do Banish Reapers and for that matter anyone who happens to roll Kill Zone outside Sharpshooters also wants it.
More subtly, Specialists want it pretty badly if you leverage the combination of Guardian and Threat Assessment, as that combo has decent odds of chaining 4+ shots in a row, which of course requires actually having 4+ shots ready to go.
Base-game Rangers who take Rapid Fire also want an Expanded Magazine, as 4 ammo is exactly two turns of Rapid Firing and Shotguns don't encourage sitting still to do a reload+fire turn, but not War of the Chosen Rangers due to the massive cooldown on Rapid Fire.
Overall, though, Expanded Magazines are fairly straightforward.
On a design level, I approve of how they're a less janky mechanic than Ammo Conservation was. Ammo Conservation was an overly-large leap, taking ammo from an omnipresent pressure to a bit of a joke. Expanded Magazines both give the game a more granular progression and also make it so ammo never becomes a solved problem for free -even if you always slap Superior Expanded Magazines on literally every soldier's weapon, that's a slot you could've spent on some other weapon, costing you something of meaning relative to players who aren't obsessive about Expanded Magazines in particular.
It helps a lot that reloading no longer ends the turn. The fact that it did in the prior game was a big part of why limited ammo was such a problem, as it meant that even reloading out of battle was risking missing a chance at an Overwatch shot. In XCOM 2, anytime you weren't going to move or otherwise spend your first action point anyway, you can reload at no meaningful cost, making Expanded Magazines more of a luxury than a necessity, aside those skills that demand ammo support. Mind, it also helps that player damage is higher and less swingy, making it so fights tend to be shorter and therefore less prone to forcing the player to reload in the middle of combat, as well as that it's much rarer for multiple pods to stumble into you at once, but just being able to reload 'for free' is a massive gamechanger that makes the core experience so much less frustrating in general.
I do somewhat wish there was a Proving Grounds project to add a little ammo (Like, +1-2 ammo) to your weapons for free in addition to Expanded Magazines so the game having certain classes basically designed around the assumption of them having more max ammo than their actual base wouldn't so heavily pressure you to give those classes Expanded Magazines throughout the game, but this is definitely a huge improvement over Ammo Conservation, design-wise.
Replaces the regular reload action with a free version that does not consume an action point, but only up to a certain number of times per mission. Once this special free reload has been used up, they return to regular reload behavior.
Boosted Superior: 4
The Auto-Loader is, in most cases, your second-line choice after an Expanded Magazine. More ammo storage is better for ammo-hungry classes than a limited number of free reloads; as a concrete example, a Grenadier has multiple skills that blow 3 ammo at once, and by extension can't be used if they're sitting on two ammo. Burning a free reload to bring back one ammo is ridiculously inefficient.
There's two big exceptions to this point.
First of all, Sharpshooters who actually care about their Sniper Rifle desperately want to be able to reload and then fire their Sniper Rifle, which an Expanded Magazine doesn't let them do. (Particularly in the base game, where the Darklance doesn't exist)
Second of all, the Auto-Loader is a counter-Codex tool, allowing soldiers to just about ignore Psi Bomb's ammo drain; instead of fleeing the bomb, reloading, and having their turn end there, they'll actually be able to take a shot afterward. (Unless they're a Sharpshooter who lacks the Darklance, but their Pistol access makes Psi Bomb less of a problem than for eg a Specialist)
Note that Skirmishers in particular pretty desperately want Auto-Loaders, since they can normally spend every single action point on an aggressive action: unlike other soldiers, spending their first action reloading isn't essentially free if they weren't going to move anyway. In conjunction with their poor ammo capacity and exceptional ability to burn ammo, it's all but mandatory to give them both an Expanded Magazine and an Auto-Loader.
Specialists and Psi Operatives often don't miss Auto-Loaders. Offensively-oriented Specialists don't have a pile of skills that can be used without necessarily ending the turn and have unusually high ability to contribute offensive action even if forced to scramble from a Psi Bomb: just burn a Combat Protocol charge, for example. Psi Operatives are even more extreme in this regard, and both classes really pretty desperately want a Scope so they can actually hit things when they do bother to pull the trigger. Specialists also want an Expanded Magazine a lot more than an Auto-Loader if they take Guardian, which is pretty easy to justify purchasing in War of the Chosen even if you far prefer Ever Vigilant.
Rangers in the base game are, if you take Rapid Fire, actually worth considering taking an Expanded Magazine and an Auto-Loader -or at least an Auto-Loader- so you can sustain Rapid Fire while staying on the move. In War of the Chosen an Auto-Loader is much less useful to a Ranger, as it's no longer possible to spam Rapid Fire, relegating it to primarily being to an anti-Codex option. And they already have melee ability for fighting while out of ammo... or even reloading and then taking a Slash to get out of the Psi Bomb's radius while still taking aggressive action.
Reapers probably would rather have a different Weapon Attachment, but an argument can be made for taking an Auto-Loader once you have Banish, particularly if you got Modular Vektor Rifles, so you can reload and unload a full Banish while still being able to move. I don't think it's a particularly great argument, but it's something to keep in mind if for some reason you feel the alternatives aren't particularly useful, or your run is swimming in Auto-Loaders and not so much in whatever you'd prefer to give to a Reaper.
Truth be told, I'm not a fan of the Auto-Loader, as far as its game design layer. The connection between its mechanics and its concept is pretty tenuous: shouldn't an Auto-Loader load ammo automatically? Worse, its actual mechanics are pretty aimless in how they fit into the gameplay, anchored primarily by the existence of the Codex's Psi Bomb ability. Outside that, what's an Auto-Loader supposed to bring to the table that isn't just the More Ammo that Expanded Magazines bring more directly? Like yes there's some implications in terms of being able to reload and move and fire in a turn without needing something like Run And Gun, but it's not so much a coherent strategic planning layer implication as it is a weird edge case of the tactical layer's design that crops up with sufficient frequency it's something to keep in mind. It's not like the game is designed so that being able to reload, move, and shoot all in the same turn fills a clear-cut niche.
Weapon Attachments are a cool little system overall, even if I have issues with several specific decisions to do with them. Because they're attached to the random loot system they encourage a little more diversity in play experiences -a run that finds piles of Superior Scopes and only the one non-basic Expanded Magazine is going to play fairly differently from a run with piles of Superior Expanded Magazines but barely any Scopes at all- and they open up the potential for different players to have different preferences and playstyles.
Ultimately, the root flaw with the system -which seems to be a bit of a recurring issue with XCOM 2's design, actually- is that it can't quite make up its mind about whether it's primarily a 'customization' system or a progression system.
This is a problem, because these are basically mutually-exclusive concepts.
This wonkiness shows through in a number of ways. Laser Sights are mostly a waste of a slot, only really worth considering on Shotguns and Vektor Rifles. Meanwhile, Scopes are good on any weapon (Yes, even Shotguns, since they make longer-range fighting more viable an option), you can merely work around not having a Scope with several weapons. The game can't make plans built around an assumption of widespread Scope usage, because no the player won't necessarily have Superior Scopes on everything to make some non-Cover-using line enemy having 20 innate Defense not a problem. The Grenadier's shooting skills seem to have been balanced to be worthwhile and fair if you assume an Expanded Magazine, making them often pretty bad if you don't attach an Expanded Magazine to their Cannon. Skirmisher design is such that if you don't attach both an Expanded Magazine and an Auto-loader to your Skirmisher their performance will drop significantly, making them almost mandatory and squeezing out other options.
If, instead, every weapon had 7 slots and you could just freely slot in Attachments with no Scope/Laser Sight conflict, this would be essentially a level mechanic for weapons, where you would gradually improve your weapons' performance over the course of a run by first filling slots with low-grade Attachments and then later by swapping them out for better ones. Among other points, it wouldn't be a centralizing design problem for Repeaters to instead add a point of damage per tier, it would just require the rest of the game's design account for it from the ground up somehow or another. (eg boosting enemy HP in the late game, and/or boosting the amount of damage gained from going to the next tech tier of weapon so they're not less important than Repeater quality, etc) This would be a perfectly fine, interesting system in its own right.
If, on the other hand, the game embraced the customization system model and tuned things so a given Attachment could be used to outright change a soldier's role, that would also be a fine system, and great for replayability and experimentation. It would require a rather different set of Attachments to function, and require probably tossing or minimizing the quality concept (That is, no Basic/Advanced/Superior tiers), but that would be a pretty cool and interesting system itself.
The actual result, where it kind of tries to be both at the same time, though? It... could easily be worse, but it's very janky. And Repeaters really just have no place in the system at all, while Hair Triggers are a clunky attempt to work around the system limitations.
Next time, we get started on more typical soldier gear, starting with armor.
See you then.