Broadly speaking, Items work much like they did in the previous game: you have a slot by default, you've got a basic grenade as your unlimited supply option, and other Items can be bought/built instantly once unlocked if you have the resources for them. The main thing of note is that where the prior game only added a second slot in the expansion, aside one class, XCOM 2 defaults to being designed around the assumption of two different Items being available from relatively early in the game -this is good, as it helps reduce the degree to which higher-quality Items tended to completely crowd out less powerful and/or more niche Items.

 Legend costs are in parentheses, though in a lot of cases this is just from the files. My own experience is that some Items don't have their cost increased by Legend even though the files list a Legend cost, or at least not consistently, such as Medikits. I'm not sure why. I'd assume it was a mod issue, except that I was running into this before I ever messed around with mods. I've run into this in both the base game and War of the Chosen, too. Other Items, like Bluescreen Rounds, have consistently applied their Legend cost in my runs. I haven't made notes of all the cases, in part because I'm not convinced this is a general issue rather than some weird interaction with my system or something, but if your own Legend runs are still using lower-difficulty prices... yeah. I already know this is a thing.


Frag Grenade/Plasma Grenade
Acquisition: Available by default/unlocked by Plasma Grenade Project
Cost: N/A
Frag: 3-4 damage, 1 Shred, radius 3, 10 range
Plasma: 4-5 damage, 2 Shred, radius 3, 10 range

The +1 is a 20% chance. This is typical of grenades for whatever reason.

 Just as with the previous game, in XCOM 2 grenades are your default Item you don't need to explicitly build. Unlike in the previous game, they tend to be phased out: while the Experimental Grenades are all inferior at terrain destruction to a Frag or Plasma Grenade, for the most part it's reasonably accurate to label them as pure improvement, as terrain destruction overall becomes less useful as the game progresses; in the early game, every enemy uses Cover. In the late game, many of the most dangerous enemies don't use Cover at all, or smashing their Cover is less helpful for some reason. (eg Codices reactively teleport/clone to a new, in-Cover location when damaged)

 Two key differences from the previous game, though: first of all, Weapon Fragments aren't a thing anymore. If an enemy would normally drop loot, killing them with an explosion will destroy the loot, so explosives kills are still something you should preferably avoid, but explosion kills are merely a chance of costing you something, not a guarantee. Furthermore, dropped loot is nice, but not critical to core Research the way Weapon Fragments were, so even if you do destroy loot with explosives it's not hurting your long-haul viability much. That right there makes it a lot easier to justify mass-kills with explosions.

 Second, Frag Grenades are initially your only source of Shred, and make for a good emergency source even once you've got other, mostly-better options. This is especially important on higher difficulties and in War of the Chosen; higher difficulties make Armor more widespread and Armor peaks higher on many enemies, and the Chosen in particular can spring an Armored target on you even in missions the Shadow Chamber assured you had none. One with enough HP that Shredding is vital; on a weaker enemy, a couple of Armor may not matter at all, amounting to a 2-hit kill regardless. On an enemy with a lot of HP, a couple of Armor is basically guaranteed to delay their death by at least one attack if you don't get it out of the way.

 These two points by themselves make grenades much more generally appealing to use, and much less of an annoying 'you can force a kill, but it'll cost you' sort of dynamic.

 A subtle tertiary point is the addition of the Concealment mechanic. Most missions you'll be able to at least once catch a full pod of three enemies in a single explosion, as pod members stick close prior to being alerted, where in the prior game you could only intermittently catch even two enemies with the same explosive unless the blast radius was fairly large.

 Another subtle point in favor of explosives is the ability to destroy the floors of buildings using explosives. Tossing a couple of Frag Grenades at some enemies sniping from high ground can tear the floor out from under them, causing them to lose their height advantage and do bonus damage via the fall damage. Nice! It's flat damage -a minimum of 2, doing more for longer falls- so this particular utility overall drops off at the game progresses... but hey, free damage.

 Also worth mentioning is that explosive blast radii now work in a manner more consistent with the grid system: in XCOM 2, a grenade is actually centered on an exact tile with a predictable radius appropriate to this, where in the prior game two different grenades that technically landed in the same tile could still hit completely different targets due to landing in different parts of the tile. A side benefit of this is that you no longer have cases where the preview seems to be indicating you'll catch an enemy in the blast but you actually won't.

 Even better, the game now provides a visual indicator of terrain you'll damage with explosives, no longer leaving you in the lurch as to whether you can or cannot blow up any given thing! The one exception to this being that ground cannot be previewed in this manner, but that's not really an issue -if raised ground has pathable ground underneath it, it can be destroyed. If it doesn't, even if it might seem like the raised ground should be destructible, it isn't. It's a very consistent rule. Also note that just because terrain is highlighted orange doesn't mean that particular explosion will destroy it, only that explosives can destroy it. Frag Grenades are able to smash most relatively frail environmental elements in a single blast, but solid-but-destructible walls and destructible floors will usually take multiple Frag Grenades to destroy.

 On that note, Frag Grenades are much more prone to actually breaking light Cover in War of the Chosen than in the base game, which is surprising as the config files indicate their environmental damage is unchanged. In the base game, you might as well assume anything hit by a Frag Grenade will fail to be destroyed. In War of the Chosen, if it's a Low Cover object or a frail-looking High Cover object (eg a stack of wooden boxes), one Frag Grenade will likely instantly destroy it. My best guesses are that a strange glitch was messing up Frag Grenade environmental damage and War of the Chosen fixed said glitch, or that in War of the Chosen many environmental objects were given less HP. Whatever the reason, this positions grenade dynamics very differently: in the base game, Experimental Grenades are basically 100% superior to Frag Grenades because Frag Grenades being able to smash terrain was barely relevant, and upgrading to Plasma Grenades is a massive boost to their relevancy. In War of the Chosen, Experimental Grenades are more lethal than Frag Grenades, but you shouldn't literally replace every Frag Grenade in your squad unless you're confident in your other sources of environmental destruction.

 Particularly important in this regard is Turret-smashing; in War of the Chosen, tossing a Frag Grenade at a Turret's floor will almost always instantly kill it by removing the floor. (Notable exception: train-mounted Turrets have sterner floors) In the base game, sometimes it will take three Frag Grenades to kill a Turret this way!

 Note that Plasma Grenades replace Frag Grenades entirely; you can't equip your soldiers with Frag Grenades once you have Plasma Grenades. Mind, you virtually never want to use Frag Grenades once Plasma Grenades are an option, but there's some terrain destruction-related considerations that make it occasionally a little annoying. Nor is it really an option to hold off, given Plasma Grenades being unlocked is necessary for Advanced Explosives...

 Narratively, the Plasma Grenade unlock makes perfect sense, which is unusual for XCOM 2. You need to Autopsy a Muton to unlock the Plasma Grenade Proving Ground Project, and Mutons carry Plasma Grenades. Crucially, they're the only enemy that carries Plasma Grenades, so there is no 'why can't I Autopsy this other thing that carries Plasma Grenades?' issue. This also neatly sidesteps the 'shouldn't you already have a stockpile of these looted?' type questions that plague equipment like magnetic weaponry, between grenades being, you know, explosives, and Mutons not being omnipresent line units. It's believable that X-COM as an organization hasn't previously gotten the opportunity to loot Plasma Grenades.


Medikit/Nanomedikit
Acquisition: Available by default/upgraded by Battlefield Medicine Project
Cost: 35 Supplies (60 Supplies)/50 Supplies and 1 Viper corpse (100 Supplies and 2 Viper corpses)
Has 1 charge that can be spent on either healing a nearby soldier (The soldier can target theirself) or Stabilizing a soldier who is Bleeding out. Clears Poison, Burn, and Acid on a healed soldier. Provides passive immunity to Poison. The heal is 4 HP by default, 6 for a Nanomedikit.

Note that any Medikits you've previously built are upgraded into Nanomedikits for free once Battlefield Medicine is completed, even though Nanomedikits are considerably more expensive than Medikits. Ideally you get all your Medikits built before you make the upgrade; you may even want to build some spares, so that if you lose any you're not screwed by running out of Viper corpses.

 I mean, Nanomedikits aren't crucial or anything, that +2 HP isn't hugely important and that's all they provide, but it's still optimal to be ahead, and you're not allowed to build regular Medikits once you've completed Battlefield Medicine. Switching to Nanomedikits, then losing all your copies and not having Viper corpses to build more is an undesirable scenario.

 Also note that the Poison immunity extends to Chryssalid Poison. As such, if you don't have a Hazmat Vest and you intend to have a soldier scout ahead to bait out Burrowed Chryssalids, you should consider slapping a Medikit onto them. Note, however, that this protection is weird: it won't actually prevent the soldier from being afflicted with Chryssalid Poison, it'll just prevent it from doing damage to them. So don't let them get killed, or make sure to cure it before that happens, if you want to avoid even more Chryssalids spawning in.

 Further note that using a Medikit will normally end the soldier's turn. This is easy to be unaware of because the Specialist's Medical Protocol doesn't end the turn and it's just so obviously superior to have a Medical Protocol Specialist handle the healing that you may never equip a non-Specialist with a Medikit at all, but it's important to keep in mind if you intend to take on higher difficulties. It's also more relevant in War of the Chosen, where the fatigue system means you're unlikely to successfully send a Medical Protocol Specialist into literally every mission. So don't be thinking a random wounded soldier can Medikit theirself and then take a shot!

 Overall, Medikits actually aren't too hugely important in general. The option to evac downed or wounded soldiers means you don't necessarily need Medikits to save a life, good play generally minimizes opportunities for enemies to do damage, and medically-oriented Specialists don't actually need Medikits to do their job. You can put off building Medikits for quite a while...

 ... with the caveat that Alien Rulers and Chosen (The Assassin, especially) make Medikits a lot more important a lot sooner...

 ...but even aside them you really should have Medikits online before taking on the Psi Gate mission/before Chryssalids show up in general. Burrowed Chryssalids are borderline-impossible to completely reliably avoid them getting a hit in; even Katana Bladestorm is only reliable on lower difficulties. So you're going to want Medikits to handle their Poison.

 Also keep in mind that Gas Grenades can be used a lot more carelessly if you have key soldiers equipped with Medikits, since the Medikits will let them walk though Poison clouds unaffected.

 Overall, the Medikit fills its niche well enough. I think the details are a bit different from how the devs imagined things working, but that doesn't change that this is quite functional.

 Narratively, the Nanomedikit unlock confuses me. It requires Autopsying Vipers, and while it's true that the distinction between 'chemistry for healing' and 'chemistry for harming' can be almost arbitrary at times, there's multiple other enemies that would relatively readily justify a Medikit boost and you'd think studying Vipers would unlock Gas Grenades and/or Venom Rounds. This is also a bit troubling from a game design standpoint in the base game, since overall Gas Grenades and Venom Rounds are worse than Incendiary Grenades and Dragon Rounds prior to War of the Chosen, and randomly rolling for them in the same pool as their superiors is... uhhh?

 War of the Chosen addresses that design issue, but the narrative oddness remains.


Smoke Grenade/Bomb
Acquisition: Available by default/upgraded by Advanced Explosives Project.
Cost: 25 Supplies (40 Supplies)/50 Supplies. (60 Supplies)
+20 Defense to all units in the blast radius for two turns. Toss range of 15. Blast radius of 4/6 for grenade/bomb. Does not count as a grenade.

Yeah, the Smoke Bomb just gets a blast radius increase, not an increase in Defense provided. The Smoke Bomb is pretty awful, its boost over the Smoke Grenade not really relevant.

 The Smoke Grenade, however, is reasonably useful. It's generally inferior to a Flashbang or Gas Grenade, as they lower enemy Aim by greater amounts while having other benefits and don't require you to clump your forces (Many enemies harshly punish clumping your forces), but Flashbangs and Gas Grenades don't work on every enemy, and Gas Grenades are furthermore locked behind Experimental Grenades. If the Shadow Chamber indicates you're fighting a bunch of robots, Smoke Grenades are what you're going to bring if you want to drop enemy accuracy.

 The Smoke Grenade is one Item I like to give to sniping Sharpshooters, particularly early in a run when there's little competition, as they're more likely to be in range to lob a Smoke Grenade at allies than to lob an offensive grenade at enemies if things go awry such that I'm not best off having them snipe. There's few compelling alternatives for beginning-of-game sniping Sharpshooters. Later on I tend to prefer to put them in either heavy armor with a Rocket Launcher or Blaster Launcher or put them in light armor for the Grapple, with Ammo usually going into the one Item slot they have at that point, but it takes long enough to reach that point it's worth considering buying 1-2 Smoke Grenades just in case. It helps that they're the single cheapest Engineering purchase; maybe you want to buy a Flashbang, but events have conspired so you can't afford one but can afford a Smoke Grenade. That might convince you to buy the Smoke Grenade.

 In the long haul, Smoke Grenades fall away in value. The further you get in the game the more common it is for you to be dealing with enemies that can bypass smoke's Defense boost, and the more strongly it becomes the case that the correct answer to a situation is to pull one pod and overwhelm it with maximum firepower. Defensive effects never become worthless, but overall offensive effects tend to be better.

 Admittedly XCOM 2 doesn't inflate enemy Aim values the way its predecessor does, but it also doesn't provide the kind of Defense-stacking that was possible in the previous game. There is no Dense Smoke, there's no Tactical Sense or Damn Good Ground, there's no Telekinetic Field, there's no innate Defense on armor... where in the previous game you could easily go over 120 Defense just by dropping Dense Smoke and a Telekinetic Field on units in Cover while equipped with any one of the various armors that boosted Defense passively, making even Muton Elites with high ground only able to hit because of the pity 1% guaranteed minimum chance on shots, in XCOM 2 you're never going to get higher than 60 Defense via Smoke Grenading troops in High Cover. That's it. That's the entirety of the Defense-boosting that is available to the player in XCOM 2 when ignoring class-specific considerations, of which Aid Protocol and Sacrifice are it.

 Enemies generally start from 65 Aim, even on Rookie, and rarely breach 80 even on Legend (Ignoring some caveats, such as how Sectopods can generally be assumed to have the high ground Aim bonus and so effectively have 90 Aim much of the time), so 60 Defense is admittedly a fairly good amount, but it's also not 'reduce enemies to 0%'. (XCOM 2 does not force a minimum 1% chance to hit) If you want to completely cripple the enemy's odds to hit you, you're usually ging to employ effects that lower their Aim, like Flashbangs and Gas Grenades. Notably, if your troops are in High Cover and an enemy is Disoriented and Poisoned, that's already such massive penalties to their hit chance that Smoke Grenades are probably not adding anything, with Disorientation disabling many special abilities and Poison doing passive damage.

 It's really too bad Advanced Explosives is merely a radius increase. Even just boosting the Defense added by 10 would have a surprisingly big impact.

As an aside, the Smoke Grenade does affect melee accuracy. This isn't a great idea to try to leverage since you'll usually end up with them benefiting from your Smoke, but it's not necessarily intuitively obvious, and can be useful in a pinch if you know about it.


Flashbang Grenade
Acquisition: Available by default.
Cost: 35 Supplies. (50 Supplies)
Disorients enemies in its blast radius, removes currently-active Overwatch from enemies, cancels most ongoing special abilities. Has no effect on friendlies. Blast radius 8, range 12. Disorientation lasts for one turn.

Flashbangs are shockingly useful. They can be used to remove Mind Control and instantly kill Psi Zombies by catching the sustainer in the Flashbang, they block access to special abilities on most enemies, including always blocking off all psychic abilities, and that's on top of Disorientation being -20 Aim, -30 Will, and -6 Mobility. Notably, Flashbangs will prevent a Codex from cloning itself when damaged, as well as teleporting or using Psi Bomb -a Flashbang can be a lifesaver if you pull a pod with multiple Codices and your squad isn't in position to for-sure kill most/all of them.

 Note, however, that the Chosen are all completely immune, as are robotic enemies. Surprisingly, Alien Rulers are not immune, though this is cold comfort since it'll last for exactly one Ruler Reaction.

 Oddly, as far as I'm aware the Flashbang Grenade isn't affected by Advanced Explosives. This makes it drop off relatively as your technology improves, though this is offset some by the presence of new threats worth Flashbanging, the most blatant being Gatekeepers. On the other hand, enemies that are immune to Flashbangs also rise in prominence; at the very beginning of the game, literally nothing is immune. Late in the game, it's not particularly implausible for a mission to be made entirely of enemies that are immune.

 At the beginning of the game, when you're not dealing with enemies immune to Disorientation, Flashbangs are astoundingly helpful for saving your squad from bad situations. The blast radius is massive, and the combination of dropping enemy Aim while denying access to special abilities such as grenades ensures that many enemies will be heavily neutered, particularly if you stack on eg Poison; with Poison+Disorientation, most of the most accurate enemies in the game will have a measly 5% chance of hitting your soldiers that are in Low Cover. (Assuming no Aiming Angle, admittedly) That's assuming they have 75 base Aim; anything with less will be completely helpless if they can't get a flank (Which their reduced Mobility impairs) or smash Cover. (Which is harder to do when they can't access most options for doing so)

 Note that Flashbangs are considered to be a grenade and so cannot be stacked with eg Frag Grenades. This is possibly their biggest flaw as you get deeper into a run, as you'd generally rather have eg an Acid Bomb for helping overcome Sectopods and Andromedons than a Flashbang. It's a bit unfortunate enemy composition isn't more varied, and also that the Shadow Chamber doesn't give you actual numbers of individual enemy types: 13 enemies where one name is Codex might mean that you'll be dealing with a pod of 3-4 Codices, in which case a Flashbang could be amazing, or it could mean there'll be exactly one Codex and a Flashbang is probably a waste of an Item slot.

 Also note that while Flashbangs are affected by Grenadiers expanding grenade range and blast radius like any other grenade, it's usually sub-optimal to actually put a Flashbang on a Grenadier. Flashbangs already have a huge blast radius and above-average tossing range, so much so that the Grenadier boosts tend to be a bit wasted on them and conversely other grenades tend to be tuned to be underwhelming when not being used by a Grenadier, which is particularly important when looking at non-Frag/Plasma grenades. Though conversely you do have the odd point that Volatile Mix will cause Flashbangs to suddenly do 2 damage, so that's... cute? Not really much of an argument to specifically have Grenadiers carrying your Flashbangs, to be honest, but it's neat that the interaction exists.

 Flashbangs are another good choice for tossing on early-game Sharpshooters. The massive blast radius and decent throw range means they can often catch enemies with it just fine, and unexpected bad situations that force your Sharpshooter to scramble for a better position have a lot of overlap with situations a Flashbang is a lifesaver in.


Nanoscale Vest
Acquisition: Unlocked by Hybrid Materials Research.
Cost: 30 Supplies, 2 ADVENT Trooper corpses. (60 Supplies, 3 ADVENT Trooper corpses)
+1 HP, passively

I most often find myself building Nanoscale Vests shortly after I've upgraded to Predator armor, where I don't have very many non-grenade Items to spread among the squad and don't really have the resources to spare on buying up eg multiple Mind Shields. +1 HP is unlikely to matter even at the beginning of the game where enemy damage is at its lowest, and this isn't the prior game where bonus HP could reduce or eliminate wound recovery time. (Well, increased HP does reduce recovery time slightly, but my point remains: +1 HP from gear isn't as valuable as in the prior game)

 It's really unfortunate Nanoscale Vests have to be purchased, honestly. If they were a free, unlimited supply, they'd still end up phased out fairly quickly, but I honestly am often dubious on actually burning Supplies on them. 30 Supplies isn't a lot overall, but in the early game that's a notable chunk of change for something with little value. Exacerbating the issue is how offensively-oriented the game is; good play will minimize the possibility of it doing anything, so for a skilled player they'll basically always be a waste of resources.

 Conceptually, Vest Items are a bit problematic, in that they drag attention to how the Item slot mechanic still doesn't really fit the conceptual framework of the game. An under-armor vest competing with stuff that goes on your belt, like most Items do, doesn't really parse. I'd sooner expect the Nanoscale Vest to go into a special Vest-only slot, and if there was a trade-off it would be something like a small Mobility reduction.

 An unfortunately-designed Item all-around, and alas War of the Chosen adding the Purifier Autopsy doesn't really change anything.


Skulljack
Acquisition: Unlocked by building the Proving Ground.
Cost: 50 Supplies and 14 days of production. (75 Supplies and 20 days of production)
Can be used to Skulljack an ADVENT Officer, and after the Encrypted Codex Project is completed can be used to Skulljack a Codex. This is necessary to advance the plot and always succeeds, generating an enemy in each case. Each Skulljacked target can be Skulljacked once per run. Skulljacking takes the form of a move-and-melee attack that automatically kills the victim, with a Hack bonus tacked on.

Skullmining: After the Skullmining Project is completed, the Skulljack provides +25 Hack to the holder. Additionally, once per mission the Skulljack can be used to Skullmine an ADVENT soldier. Skullmining is a move-and-melee attack with a 70% chance to hit; if it misses, the target takes 2 damage that ignores Armor, and the soldier attempting the Skullmining only uses up one action point even if they Dashed. If it succeeds, the soldier attempts to Hack the target, with the choices being between earning some Intel or earning a Facility Lead. Succeeding in the Hack will provide the selected reward, while failing the Hack will do 3-4 damage to the Skullminer. Either way, the target is killed by the attempt.

Skullmining originally only did 20 damage to its target, but War of the Chosen ended up patching it so that it would actually kill enemies even if you have the doubled-HP setting enabled.

 Also, Skulljacking will display a 70% chance to hit, just like Skullmining, but this is a lie. It always succeeds, no matter what.

 Also note that while the Skulljack has only one charge, that's for each ability. It's absolutely possible to Skulljack a Codex and Skullmine some poor ADVENT trooper in the same mission with the same soldier. This is mostly a very mild convenience feature that serves to be mildly confusing to a new player, as it's not intuitive that these are separate abilities. The game might've been better served making Skullmining unlocked by Skulljacking a Codex, so the game could simply swap out Skulljacking with Skullmining with the player none the wiser. This would've pushed the Skullmining to be more of a midgame upgrade, but honestly, Skullmining isn't very useful, especially not when you first unlock it. I'll come back to that in a bit.

 At its most basic, the Skulljack is XCOM 2's replacement for the Arc Thrower, adjusted to accommodate the fact that XCOM 2 has a notable portion of the missions be ones where X-COM abandons the field without looting everything. Instead of capturing enemies and interrogating them being an important part of the process of moving forward in the early game, you basically perform a field interrogation, allowing the Skulljack to not be a waste of time on the many, many missions where you'll be leaving without loot, while making logical sense. (This can be contrasted with how the Alien Hunters DLC doesn't even bother to explain how you 100% consistently loot the Alien Ruler bodies. It's not like they drop it as yellow loot your soldiers can pick up...)

 This is a bit of a disappointing implementation of what sounds like a fairly hardcore, amazing concept. 'Skulljacking' sounds like hacking cyborgs to serve your own purposes by plugging into their skull, or something equally amazing. Skulljacking itself is also only used twice in the game, with your other plot-critical missions being based around picking up physical loot, leaving Skulljacking feeling a bit tacked-on of a mechanic. I appreciate the general attempt to come up with something that's less awkward/frustrating than the Arc Thrower while also fitting into the circumstances of XCOM 2's gameplay/narrative framework, but the execution could've been better.

 Anyway, Skullmining. It's basically like Hacking a robot or terminal or security tower, only you're doing it to a live ADVENT soldier. Like Skulljacking, this is an amazing-sounding concept whose execution is... kinda iffy.

 First of all, all you can get out of Skullmining is either Intel or a Facility Lead. Intel is okay and thematically appropriate, but a Facility Lead is generally pretty eh, even if it's also thematically appropriate. In spite of ADVENT soldiers being directly stated to have control chips, you're never going to get to Skullmine an ADVENT Shieldbearer into giving your troops that snazzy shield. This is disappointing and also frankly a bit confusing, given the engine absolutely supports mostly-permanent mind control of enemies and the narrative elements are there for it to make sense for Skullmining to be able to produce that result.

 Secondly, the Tech rating on ADVENT soldiers is uniformly quite high. This is true on every difficulty and for every tier of ADVENT soldier. As such, only Specialists have any real chance of getting something out of an ADVENT soldier... and even they can't get great odds unless you use Hacking rewards to pump up their personal Hack score on top of leveling them and upgrading the Gremlin. Skullmining is thus only particularly useful for forcing a kill while accepting HP damage, with any actual Hack rewards as a bonus...

 ... which hits third, that the chance of actually successfully initiating the Skullmining is a flat 70% no matter what, ignoring even stuff like Holo Targeting. If it were possible to get that initial hit chance to 100%, the Skulljack would be an excellent ace in the hole, able to down an ADVENT Shieldbearer right through their shield completely reliably at a small HP cost. That's the sort of thing that can save the entire squad in a bad situation.

 It can still do that, of course, but it can also utterly fail and leave you with someone standing in the open who, if they'd burned the Item slot on a grenade or something, could've ensured something actually useful happened.

 The fact that it actually constitutes a proper Hack is also an important factor in limiting its utility from another angle: a Ranger or Templar is already designed to charge into the open without dying, but if you give them a Skulljack they're basically guaranteed to fail a Skullmine. If you instead give it to a Specialist... well, they'll be halfway competent at the Hacking part, but they're not a class you really want charging the enemy's line. Furthermore, for non-Specialists it tends to be difficult to justify slipping a Skulljack into an Item slot because they have other things they fairly desperately need/want to operate at peak efficiency. Sure, your Spidersuit Ranger could burn their precious one Item slot on a Skulljack... or they could take a Hazmat Vest so they can fearlessly charge through environmental hazards, a supremely useful effect for them. Or a Mind Shield, to ensure that if their melee shenanigans get them separated from the squad you don't have to worry about them also getting Mind Controlled while the Mind Controller is not in a convenient position to be killed/Flashbanged/whatever. Or almost any grenade, so they can help Shred the Sectopod you know is somewhere in the mission. Or Bluescreen Rounds, so they can Rapid Fire said Sectopod for massive damage.

 In practice, the main utility of the Skulljack aside advancing the plot is that once you've finished Skullmining it functions as a general Hack booster for your Specialists, who should be doing most of your Hacking anyway. With Predator/Warden/Icarus Armor, it's perfectly possible to cram a Medikit and Skulljack onto a Specialist so they can perform medical duties and Hack effectively.

 The whole thing is weird and janky and I don't really get the decisions being made here past the initial, very general impulse.

 For more problems there's the aesthetic/conceptual stuff. Even more so than vests, the Skulljack drags one's attention to how Items tend to not fit into the Item slot mechanic particularly well. If you pay attention, you can see that the Skulljack goes over the arm of your soldiers. So... logically speaking, why does it compete with your other stuff?

 It's also one of the most futuristic-without-thinking-about-it things in the entire game, in that the Skulljack is transparent and the parts are able to magically separate out with no connection points whatsoever, the whole thing suggesting it's some ridiculous 'hard light' construct that doesn't have to pay much attention to conventional physics. Given this is a juryrigged early-game-by-definition piece of technology... um... what?

 I'm not really sure why the Skulljack is the center of so many wonky, iffy decisions.


Mind Shield
Acquisition: Unlocked by Sectoid Autopsy.
Cost: 45 Supplies and 1 Sectoid corpse. (60 Supplies and 2 Sectoid corpses)
Passively renders the soldier immune to all negative mental effects, up to and including Panic and Mind Control. This includes Daze in War of the Chosen.

The Mind Shield is a very different Item between the base game and War of the Chosen.

 In the base game, it's moderately neat but not generally worth taking except maybe into the final mission so you don't have to worry about an enemy Mind Controlling someone out of position such that you can't kill the mind controller smoothly or remove the Mind Control via Solace Psi Operative. Past the early game your soldiers will almost never Panic on their own while Sectoids are the primary thing Mind Shields protect against, and you usually want them using Mindspin since you can promptly cancel its effects by killing them or Flashbanging them. (Where them taking a shot will, if it hits, at minimum result in infirmary time) There's value, sure, but it's pretty eh overall, and there's too many other Items competing for your slots while being more clear-cuttedly worth taking.

 It can also be worth considering temporarily slapping onto a Shaken soldier so their crippled Will isn't an issue, I suppose?

 In War of the Chosen, the Mind Shield is downright amazing. Not in every situation all the time, or even in many situations, but in the situations it helps in it just plain shines.

 Most blatant: the Warlock. A Mind Control-capable enemy you can encounter from quite early on who is immune to Flashbangs and durable enough you can't necessarily nuke him down to cancel the Mind Control. If nothing else it's worth considering equipping Mind Shields on everyone when you assault his Stronghold.

 More generally, the Chosen are all capable of inflicting Daze en mass, and even having one or two soldiers with a Mind Shield can mean the difference between half the squad being out of action for a full turn vs two merely losing an action point while a third is completely fine. Which itself can easily be the difference between the Chosen killing, kidnapping, or interrogating someone vs you driving them off that turn.

 However, a key, unexpected advantage: it even blocks Panic checks caused by Phobias and exhaustion! The Mind Shield can thus allow you to send a Tired soldier right back into the field if the situation is bad and you feel you need them on a mission you need to do right now, without having to worry about them completely falling apart. They'll still be at risk of picking up new Phobias, but at least they'll be functional, and you can always get those removed at medical later. On that note, it can let you put off putting a soldier through therapy, such as because you haven't even built the relevant facility, such that even a soldier burdened with one of the particularly problematic Phobias, or multiple Phobias, will remain calm under pressure regardless.

 This does come with the caveat that the Bond system somewhat offsets the Mind Shield's increased relevancy. If your squad is made entirely of Level 3 Bonds and/or SPARKs, you don't actually need Mind Shields for protecting against Mind Control, for example. However, this is a fairly minor caveat, as the Mind Shield's ability to keep Tired and Phobia-heavy soldiers calm is completely unmatched; Bonds cleansing mental effects doesn't prevent them, and so you can't have a Bond soldier babysit their Tired Bondmate to keep them from Panicking.

 It's also particularly useful for Bladestorm/Retribution soldiers, since Bondmates can't clear Mind Control on them without triggering a strike first. Just sidestep that whole thing by giving Rangers, Skirmishers, and lucky Templar Mind Shields.

 Narratively, this unlock is pretty questionable, but the most logical alternative wouldn't actually be acceptable due to how the game is constructed. So whatever.


Battle Scanner
Acquisition: Unlocked by ADVENT Trooper Autopsy.
Cost: 30 Supplies. (50 Supplies)
Has a toss range of 28 tiles. When thrown, reveals all tiles in a radius of 12: this will not activate enemy pods in the area, but it forcibly reveals hidden enemies. (ie Faceless pretending to be civilians, Burrowed Chryssalids, and Concealed units of any kind) Has 2 uses, and does not necessarily end the turn to throw. Does not provide Squadsight targeting.

Note that while the game describes the Battle Scanner as being 'thrown like a grenade', it is not treated like a grenade for any purpose. You can't slot it into the grenade-only slot on Grenadiers, it doesn't get toss range or radius expansion from the Grenade Launcher, Volatile Mix doesn't affect it, etc. You're generally better off putting into a non-Grenadier's hands. Conversely, it doesn't compete with actual grenades.

When you first unlock the Battle Scanner, it's... pretty baffling. There's no hidden enemies to forcibly unveil, and the forward scouting utility is already heavily handled by the Concealment mechanic. It can act as something of a supplement after you've broken squad-wise Concealment, but this is limited by things like Rangers and Reapers existing to fulfill the role of forward scout, and it requires you to have good judgment on whether enemies are just out of sight or not. Which... if you do have good judgment in that regard, it's just redundant!

 You might want to build one ahead of your first Retaliation mission, though, so you'll be able to reveal Faceless in large groups of civilians more safely.

 Actually, in general the Battle Scanner is mostly useful in Retaliation missions in the base game. Without Dark Events, Faceless and Chryssalids can only show up in Retaliation missions and, in the case of Chryssalids, a couple of plot missions, and the only way you have to worry about Concealed enemies is if one of your Rangers gets Mind Controlled while having a charge of Conceal on hand. And I'm not sure the AI would bother to use it, even then. Plus Retaliation missions don't give your squad Concealment, so their utility in scouting without activating a pod is considerably more relevant than in a regular mission.

 It's notably more general in War of the Chosen, with Spectres and the Chosen Assassin both able to enter Concealment. It's also boosted by the fact that loner Chryssalids reveal their Burrowing to you when they do it; if you have a decent memory, you can potentially force out a group of Chryssalids with a Battle Scanner instead of having someone act as bait. On the other hand, War of the Chosen also makes it more practical to be incidentally carting along a Scanning Protocol Specialist, which is generally more efficient than carting along a Battle Scanner. There's also the point that getting the Chosen Assassin's Katana potentially allows any Ranger to scout for Burrowed Chryssalids in complete safety if you're below Legend difficulty (So long as the Ranger has Blademaster), and by a similar token if you get lucky with rolling Bladestorm on a Templar they can end up an extremely safe scout for Burrowed Chryssalids as well. (At Focus Level 3 with Celestial Gauntlets, they'll always kill fresh Chryssalids below Commander, and have a 50% chance of one-hit-killing them on Commander. If you have the Improved Beam Weapons Breakthroughs, this becomes 100% safe)

 Of course, on Legend difficulty these tactics don't work as well, so the Battle Scanner becomes more worth considering. Still... a bit underwhelming, honestly, but if you're trying Legend for the first time and normally ignore the Battle Scanner, you should keep in mind that it's more relevant.

 Narratively, this feels like a bit of a missed opportunity. If ADVENT Troopers carried Battle Scanners they used when suspecting Concealed soldiers were in the area, that would both tie things together in terms of the unlock and make ADVENT Troopers a more interesting enemy, particularly in War of the Chosen. Not too big a deal, but it would've been neat.


Overdrive Serum
Acquisition: Unlocked by Berserker Autopsy.
Cost: 35 Supplies and 1 Berserker corpses. (60 Supplies and 2 Berserker corpses)
Can be used once, ever (You don't get it back after the mission), but is completely free to activate otherwise. For this turn and the following turn, the soldier has +5 Armor, +5 Mobility, and is immune to Disorientation, Daze, Mind Control, and won't Panic.

If it weren't for the fact that it's outright used up when used, I'd consider this a massive improvement over the prior game's Stims, which were complete garbage.

 As it is one-use-period, it's still pretty garbage. In part because you generally don't collect very many Berserker corpses in a given run.

 On the plus side, that limitation doesn't really matter in the final mission, so if you've got Berserker corpses lying around it's worth considering building some and passing them out.

 On the minus side, it's a long mission, and you'd probably be better off equipping an Ammo Item or something.

 I really don't get why Overdrive Serum, and only Overdrive Serum out of base-game Items, was made one-use-ever. I'd get it if it lasted the entire mission, or even just something like 5-10 turns where you could plausibly expect it to last through two pods' worth of fights, but as-is? Why? Yeah, +5 Armor is quite a lot, but pity damage means it's not actually invulnerability, and it only lasts two turns, and, again, it demands a valuable Item slot.

 It's not the worst Item in the game, but it's certainly competing for the slot.

 It's also moderately annoying that Overdrive Serum is clearly supposed to be derived from Berserkers berserking, but the only mechanics overlap is that they both boost Mobility. Berserkers would be a much more interesting threat if they got a massive Armor boost and immunity to mental effects from becoming enraged.


Mimic Beacon
Acquisition: Unlocked by Faceless Autopsy.
Cost: 75 Supplies and 2 Faceless corpses. (100 Supplies and 3 Faceless corpses)
Thrown like a grenade up to range 10. At the targeted location a hologram of a soldier with 12 HP is generated, which lasts until the start of your next turn. Most enemies will heavily prefer to focus on the Mimic Beacon over targeting your own soldiers.

Compared to the vague, not-very-useful Mimic Beacon of the previous game, XCOM 2's Mimic Beacon is actually quite good! An on-demand meatshield that enemies do in fact preferentially target is a useful stop-gap measure when things are going wrong and you need to buy a turn, and it's tough enough that even endgame enemies will normally need to hit it at least twice to break it. 

 Furthermore, the AI heavily prioritizes targeting the Mimic Beacon, to the point that this will often overrule actions the AI normally is all but guaranteed to take, such as ADVENT Shieldbearers putting up a shield. Usually if an enemy doesn't take a shot at a Mimic Beacon, it's because they ended up not having a clean line of fire to it, or it got destroyed before they could act. This can be incredibly useful if you really do not want an enemy performing a special action, such as preventing an ADVENT Heavy Mec from using its Micromissile bombardment on troops you have clustered on high ground. The Mimic Beacon is actually uniquely useful in this regard, as even special abilities Flashbangs and fire won't suppress (eg Shieldbearer shields) or enemies that can't be Flashbanged or set on fire (eg robots) can be prevented from using special abilities in this way. And where a Flashbang or Incendiary Grenade can lead to an enemy taking a shot at one of your soldiers and getting lucky, instead of using a less immediately threatening ability, the Mimic Beacon will eat their turn outright, making it actually even safer!

 Cover-using enemies with a melee attack can also fairly reliably be pulled out of Cover by placing a Mimic Beacon in their reach with no Cover to stand next to, particularly Mutons. Even non-melee-capable enemies will sometimes get confused and decide they want to spend their second movement action running into the open next to the Mimic Beacon!

Keep in mind it's not 100% reliable, though. Enemies do strongly prefer to target it, but XCOM 2 AI is still ultimately fairly random in its decision-making. If you use Mimic Beacons a lot, every once in a while they'll just randomly fail to distract one or more enemies.
Enemies targeting a Mimic Beacon are supposed get a massive Aim bonus against it, specifically +1000 Aim, so theoretically it should be essentially impossible for them to miss. In practice they still do sometimes miss; I'm not sure if the bonus isn't actually enabled or if it gets applied inconsistently or what, but whatever the case a Mimic Beacon will intermittently distract more firepower than it seems to be intended to do by virtue of misses delaying its 'death'.

 Note that the Faceless are, for presumably thematic reasons, one of the only enemies that will ignore a Mimic Beacon entirely. Don't waste time trying.

 Also note that while it's thrown like a grenade, it's like the Battle Scanner and isn't affected by abilities that modify grenades, but it also doesn't compete with grenades.

 And to be clear, while the holographic soldier derives their appearance from the throwing soldier, there's no stat inheritance involved. You don't get added value from throwing a Mimic Beacon with a soldier who has a couple points of Armor or anything like that. You should be giving it to soldiers where them spending their turn on throwing a Mimic Beacon isn't liable to compete with urgently important tasks, or to a Skirmisher with Total Combat so they can toss it without ending their turn.

 This being unlocked by the Faceless Autopsy makes no narrative sense, but whatever. Nanomedikits and I guess the Stasis Vest are the only alternatives I'd argue make more sense for coming from the Faceless Autopsy, and that has the issue that it's not like there's a better Autopsy for justifying the Mimic Beacon, narratively.


Proximity Mine
Acquisition: Unlocked by Andromedon Autopsy.
Cost: 100 Supplies. (125 Supplies)
Tosses a mine up to range 12. Tossing the mine does not break Concealment. The mine will detonate when an enemy moves within its blast radius, doing 6 damage with 2 Shred to all units in a blast radius of 4, as well as damaging or destroying terrain elements. Breaks squad Concealment when it detonates. Counts as a grenade.

The Proximity Mine is an excellent Item for Tactical Rigging Reapers, allowing them to contribute major damage without breaking Concealment. It's also a great tool for ambushing reinforcements, which is hugely helpful on a few missions -the big example being base-game Avenger Defense missions. It's also an excellent tool for initiating an Overwatch ambush, as activating a pod by having them trigger it during their turn will basically let you double up on turns, where a normal Overwatch ambush only gets you one advantaged turn over the enemy, and simply dropping it in the middle of a pod during your turn basically guarantees it'll trigger. After all, if the pod moves at all, it'll detonate.

Do note, however, that having the Proximity Mine detonate during the enemy's turn has the rather bizarre property of potentially leading to enemies taking a potshot if any of your troops are standing in the open or flanked at the time of the explosion just as if a pod discovered your squad while patrolling, even if your soldiers aren't within any enemy's detection radius! As such, you should be careful to make sure your soldiers are all in a good defensive position anyway, as otherwise there's high odds you'll lose someone to a crit.

 The bizarre thing is that you still get to avoid Overwatch penalties, like a proper Overwatch ambush.

 Another unpleasant surprise is that Blazing Pinions and Devastate, though they involve the Archon or Archon King moving, don't trigger a Proximity Mine even if they're standing atop it when they launch.

 Also note that, unlike Claymores, Proximity Mines cannot be detonated by other explosives. This largely isn't important, but there's edge cases where it can crop up.

 The Proximity Mine doesn't quite displace Plasma Grenades in practice due to being unable to deliver damage/Cover destruction on demand, but it's strongly worth buying a few. It helps that generally you unlock it around the time Supplies are no longer a particularly precious resource.

 I do find it pretty weird that it's unlocked by the Andromedon Autopsy. I don't get why it wasn't the Acid Grenade or Hazmat Vest that was placed here. Proximity Mines would make perfect sense as an Experimental Grenade, and Acid Grenade or Hazmat Vest would make perfect sense for an Andromedon Autopsy unlock. I'm not seeing a good gameplay reason for this, either. This is genuinely one of the most baffling Item unlocks; most stuff being a bit off I can understand the awkwardness of what happened, like how Gremlin and Psi Amp unlocks have a janky distribution due to logical enemy choices being few and spread awkwardly for a natural unlock progression.

 This is just confusing.
Hellweave Vest
Acquisition: Unlocked by Chryssalid Autopsy.
Cost: 65 Supplies, 2 Chryssalid corpses. (60 Supplies, 3 Chryssalid corpses)
+2 HP, melee attackers take 2-4 damage and are always set on fire.

... yay?

 If you've not made any Experimental Armors and you're still finding yourself using Nanoscale Vests you might as well build some Hellweaves to replace them, but I don't really get the Hellweave. The most worrying aspect of Chryssalids is their poison effect, and Hellweave does nothing to protect against that. (Even if its damage kills them, it only does so after their attack completes) Nor is it particularly great against other melee threats.

 It's also narratively confusing that Hellwave comes from the Chryssalid Autopsy. I would more readily buy literally any of the Experimental Vest results as a Chryssalid Autopsy product, narratively, and they'd all have a clearer gameplay payoff to boot.

 I honestly don't understand Hellweave at all.

It does admittedly hard-disable dedicated melee enemies in the base game? But, y'know, only after they attacked. And only if they attacked the right soldier. So... not exactly a big draw.

Bluescreen Rounds
Acquisition: Unlocked by Bluescreen Protocol Project.
Cost: 75 Supplies. (125 Supplies)
+5 damage on primary weapons and Sharpshooter Pistols and Templar Autopistols against digital enemies, and such shots lower enemy robot Tech Defense by -5, stacking indefinitely with further hits. Primary weapons and Pistols/Autopistols will also completely bypass shields, removing them on a successful hit without any damage being absorbed by the shield.

A fantastic Item in the late game and I'm frustrated it wasn't thrown into Experimental Ammo, as it tends to overshadow all other ammo types, particularly in the base game; the Chosen help mitigate this particular issue.

 Note that while it lowers Tech Defense on hit robots, this is largely impractical to try to abuse. -5 Tech Defense isn't enough to swing things by itself, and Bluescreen Rounds have enough of a damage boost that it's not very practical to stack the penalties except against Sectopods -and even there it's only really practical on higher difficulties and using Sharpshooter Pistols so you do only minor damage through their Armor. It's honestly pretty confusing that Bluescreen Rounds have this effect.

And yes, Bluescreen Rounds let you flat-out bypass ADVENT Shieldbearers. If you've got a couple of soldiers with Bluescreen Rounds in a mission, you can basically ignore a Shieldbearer for their first turn, particularly if one of those Bluescreen Rounds soldiers is a Sharpshooter with Faceoff, allowing you to mass-remove the shields without specifically needing to kill the Shieldbearer. Ideally you'll kill them anyway, mind, so they don't get a chance to take a shot, but if you've got more threats active than you can kill, Shieldbearers are one of the less problematic enemies to leave alive if you're able to ignore their shields.

 Bluescreen Rounds is one of the few Items that is meaningfully pricey when first unlocked and yet also very tempting to purchase. It's Just That Good, particularly in the base game.

 Narratively, this makes perfect sense, more or less. Breakdown the first robot enemy, turn your newfound understanding of enemy robotics into tools for more readily defeating enemy robots. Makes sense, even if the details are weird. (eg it beating Shieldbearer shields is... uuuuh?... and similarly not all susceptible enemies are actually robots)
EMP Grenade/Bomb
Acquisition: Unlocked by Bluescreen Protocol Project/Improved by Advanced Explosives Project
Cost: 50 Supplies regardless of difficulty.
Against most enemies, does nothing. Against digital enemies, does damage that ignores Armor, lowers Tech Defense where applicable, and may Stun its victims. Additionally, it erases Shieldbearer-induced shields from any unit caught in the blast.
Grenade: 6 damage, -5 Tech Defense, 4 blast radius, 12 range
Bomb: 10 damage, -10 Tech Defense, 5 blast radius, 12 range

The EMP Grenade's primary flaw is that it completely lacks Shred, when the enemies you want to use it on are all tough and mostly Armored. Its secondary flaw is that Bluescreen Rounds is usually superior at accomplishing its duties, while being unlocked by the same Proving Grounds Project and not having a limited number of uses in a mission. Its primary edge over Bluescreen Rounds is the potential to Stun a Sectopod.

 In practice, it's usually not worth purchasing if you're playing below Legend. It's not lethal enough to be a one-hit kill on most susceptible enemies, even with Advanced Explosives on lower difficulties, its Stun is not guaranteed, its damage isn't really far enough ahead of Bluescreen Rounds to make up for it being single-use per mission, and most susceptible enemies do not occur in groups of susceptible enemies under normal conditions.

 Legend gives it a new lease on life, as its cost does not go up on Legend while Bluescreen Rounds does. It's actually plausible you'll be wanting more anti-electronic firepower and not have the Supplies to afford Bluescreen Rounds -indeed, on Legend you can potentially buy two EMP Grenades while being unable to afford Bluescreen Rounds!

 War of the Chosen also helps it a lot, albeit unreliably, due to the introduction of Sitreps. As one Sitrep ensures the enemy composition will be entirely or nearly-entirely digital enemies, for such a Sitrep there's little reason to not bring some EMP Grenades if you can. You can't count on any given run having this crop up, but this is still a big boon to it.

A more bizarre way War of the Chosen helps it is that the sarcophagus you need to destroy in Chosen Stronghold assaults is actually fully susceptible to EMP Grenades! An EMP Bomb backed by Volatile Mix means doing 12 damage, which is above-average even compared to endgame guns, and Grenadiers can reliably grab Salvo to slip the damage in atop their shooting action. So that's a circumstance EMP Bombs are strongly worth considering buying and building -and no, Bluescreen Rounds don't get bonus damage against the Chosen sarcophagus, so they can't push out an EMP Bomb on this topic.
Volatile Mix will, in fact, add +2 damage to these, but they will still do 0 damage to most enemies. The boost only applies to the already-susceptible. On Commander, that's enough to turn an EMP Bomb into a one-hit-kill on Codices, guaranteed. Even on Legend, they'll at least not clone. So that's a potential reason to consider EMP Bombs. You can see 3-Codex groups, after all, and they're a bit of a pain to kill conventionally.

 Narratively, this is even more intuitively obvious for connecting to the ADVENT Mec Breakdown than Bluescreen Rounds, and also more intuitive for it being a reasonably general anti-electronic effect. It's probably just an EMP burst effect, essentially. Indeed, my primary complaint is that it really ought to be more generally useful than it is; your enemies are all running around in armor that almost certainly has integrated electronics of various sorts. Something as simple as Disorienting ADVENT soldiers as a representation of their suite of electronics being temporarily down would make perfectly logical sense and have made the EMP Grenade a lot less terrible in the base game release.

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Note that the following three Items are added by and thus exclusive to War of the Chosen.


Ultrasonic Lure
Acquisition: Unlocked by Lost Autopsy.
Cost: 30 Supplies. (60 Supplies)
Tossed like a grenade up to range 28. Has a blast radius of 12. Draws Lost to the Lure. Has two charges.

The Ultrasonic Lure is basically a gimmick. It's useless if the map doesn't include Lost, questionable if the map has Lost but no non-Lost enemies, and even when there's Lost and non-Lost it's not necessarily worth the bother. (Among other things, it does break Concealment to throw it, and so you can't use it to pull Lost toward an ADVENT pod you'd like to soften up before fighting) The big problem is that it's the only reward for Autopsying Lost, and even if you roll a Lost-corpse-providing mission (A Lost-containing mission is guaranteed early in the game, but this particular case is never a mission where you loot bodies), there's just so many other priorities that are more generally useful that it's difficult to justify burning Research time on the Autopsy. I suppose you could abuse Lost spawn mechanics to kill 80+ in your very first body-looting Lost mission and so hit the instant-Autopsy threshold right away, making that particular concern moot...

 ... but the Ultrasonic Lure struggles to justify itself regardless. Lost go after ADVENT/Alien forces on their own semi-reliably and will do so completely reliably if your squad is still in Concealment, and I wouldn't want to bet on the AI cooperatively chasing down the Ultrasonic Lure over targeting your forces when this doesn't apply. XCOM 2's AI isn't put together well enough for me to trust that.

 Also note that using the Ultrasonic Lure has the same sort of effect as tossing a proper explosive in terms of accelerating Lost wave spawns. This is another reason why it's a dubious Item; in theory, you can use it to save yourself trouble with AI infighting, but Lost spawn mechanics mean that spawning a new wave is basically guaranteed to be causing you trouble, while probably not causing trouble for the Aliens.

 Alas. I like the idea of it, but the execution is extremely lackluster. Don't even bother building it unless you just want to have fun messing around with it.

 Narratively, the unlock is... wrong on a details level, in that honestly I'd think Shen could cook up the idea without needing Tygan to study them, but the basic flow of 'encounter Lost->now you understand them enough to think to make an Ultrasonic Lure' makes perfect sense at the broadest level. Sure, whatever.


Sustaining Sphere
Acquisition: Unlocked by ADVENT Priest Autopsy.
Cost: 50 Supplies, 1 ADVENT Priest corpse. (75 Supplies, 1 ADVENT Priest corpses)
If the equipped soldier would die, instead they go into Stasis with 1 HP. Upon activation, the Sustaining Sphere is lost forever.

This is a moderately neat thing to have, making it a little less risky to eg have a soldier you've invested a ton of AP and Covert Operation bonuses into, as you can ensure they won't drop dead from one turn of bad luck. If you're still learning the game, or are Ironmanning things (Don't do this, the game is sufficiently prone to gamebreaking bugs you're unlikely to actually complete your campaign), this can be a great Item to put on favorite soldiers.

 Once you're reasonably skilled, it's a lot more dubious. Your soldiers mostly shouldn't be getting into that kind of trouble in the first place, and giving them a Sustaining Sphere may be what leads them into such trouble, in the sense that a different Item would've let them prevent the situation from deteriorating that far in the first place. The main caveat here is that Lost+ADVENT missions can be horrifying, chaotic messes where things go uncontrollably wrong with little ability on your part to avoid it through better play. I personally just reload when things go really, really wrong in these situations (There's too many janky, screwed-up mechanics regarding Lost+ADVENT for me to feel like I'm 'cheating' by reloading in the face of catastrophes caused by said bizarre mechanics), but if you're stubbornly insistent on never reloading outside of actual gamewrecking bugs... yeah, you might want to give everyone who doesn't have natural Sustain a Sustaining Sphere in such missions.

 The fact that it's used up forever when triggered and Priests are somewhat uncommon is a particularly limiting factor, especially if you have odd luck and keep getting Priests in missions where you don't loot corpses. Even if you love the Sustaining Sphere, you may not be able to build more than a handful. Though conversely if you eg get an early Psionic Storm, you may have more Priest bodies than you know what to do with...

 Narratively, this is, uhhhh, weird. It seems to be operating under the same logic as ADVENT Priests getting Sustain; psionically putting themselves into Stasis at the last second. This is obviously a technique rooted in psionic ability, not a device. So being able to build a device that does it for your troops by studying one of these people... this really ought to either be impossible, or suggest literally any Psi Operative technique can be extracted and codified in technological form. And without needing to cut open the dead.

 I'm willing to gloss over this, partly because the idea of a 'save your soldier's life' Item makes perfect design sense and Sustain is right there to copy+paste, but if XCOM 3 returns to any vaguely similar idea I hope more thought is put into it, 'cause this has implications I don't think are at all intended.


Refraction Field
Acquisition: Unlocked by Spectre Autopsy.
Cost: 50 Supplies, 1 Spectre corpse. (100 Supplies, 2 Spectre corpses)
Once, the soldier may immediately enter Concealment. This ends the user's turn, and the Refraction Field is lost forever.

That's right: Refraction Field is recycling the icon for Mimetic Skin from Enemy Within.

I'll be getting into this a lot more over time, but this is one of many examples of War of the Chosen not being fully completed when it was released. The graphic works fine, I'm not objecting to its usage, but I'm strongly confident it made it into the final game entirely due to them not getting around to making a new graphic in time for release, not as a deliberate decision to be efficient.

 Refraction Field itself is... ehhhh. I'd generally rather burn some Ability Points on purchasing Conceal or Phantom on a soldier. I can maybe see an argument for building a few if you're playing with Grim Horizon on and High Alert shows up before your team is really developed enough to have a good array of Concealing scout options, but overall it's just kinda... there. If it was once-per-mission, it would be somewhat niche, but kind of cool, potentially worth tossing on a Ranger for an extra Shadowstrike trigger, or other more creative uses. Since it is once-ever, you really need to have an extremely strong certainty that you'll get a lot of value out of it this mission for it to make any sense to build and bring along. High Alert is really the closest thing to a clear-cut 'here's where Refraction Field is Very Good' situation.

It does have the potentially-useful quirk that a Reaper using it will enter Shadow, and more specifically that it's a way to work around the fact that normally Reapers can't re-enter Shadow the same turn they break it. I don't care enough to use this, personally, but it is a unique advantage.
Narratively, this is... yeah, sure, Spectres can enter Concealment, but the game pretty heavily implies Spectres can enter Concealment because of the nature of what they are, in a manner that your crew really shouldn't be able to imitate with a device. There's a straightforward gameplay connection -get Concealment Item from Concealing enemy- but the underlying world elements are pretty confusing if you try to think deeper on them.

 -----------------------------

 Overall, regular Item balance is a bit better than in the prior game, but unfortunately there's still a pretty strong trend of the game having a few very good Items, a few kind of good Items, and a bunch of cruft you tend to ignore because it's lackluster or too niche with the game not designed to ever predictably maximize said niche. I'm sympathetic to how this happened, but it doesn't change the fact that this is one of the weaker elements of XCOM 2's design.

 Alas.

 Next time, we move on to Experimental Ammo.

 See you then.