XCOM 2 Item Analysis: Experimental Grenades
Experimental Grenades work a lot like Experimental Ammo, including costing the same and taking just as long to build, it's just the final result is a grenade. Thankfully, while you only get one copy per Experimental Grenade Project performed, these are magical grenades that reassemble themselves and then teleport to their holder after missions, so just like with Ammo you only lose them if the carrying soldier('s body) gets left behind, rather than needing to build a new one every time you use the existing one.
Note that all three Experimental Grenades don't actually do direct terrain damage, which is an important disadvantage relative to Frag/Plasma Grenades. Also note that all three Experimental Grenade types have a mere 20% chance of rolling their +1 damage, making their listed damage ranges deceptive compared to eg primary weapons, though this is the same as with Frag/Plasma Grenades so that particular comparison is thankfully relatively straightforward.
All Experimental Grenades have a basic version and then an advanced version that's (name) Bomb instead of (name) Grenade. Performing the Advanced Explosives Proving Ground Project causes all current and future grenades to upgrade for free. Visually, Bombs just put a little graphic in the corner of the graphic; if they have modified in-battle visuals, I haven't noticed.
Do note that it's possible for a Rumor to generate a basic Experimental Grenade after you've finished Advanced Explosives. You may want to sell these at the Black Market to avoid accidentally giving one of your soldiers an unnecessarily weak explosive. Any Experimental Grenades you acquire before completing the Project will be upgraded regardless of their source, so if you happen to have things line up such that you'll complete a Rumor that provides an Experimental Grenade shortly after you would complete Advanced Explosives, you may want to arrange to delay Advanced Explosives to avoid this scenario. (You can do this without losing any current progress simply by reordering the Proving Grounds production queue so something else is in front of Advanced Explosives, and then shifting it back after you've done the Rumor if you still want it done soonest)
Also note that Grenadiers with Heavy Ordnance are generating a second use out of thin air. You don't need two Acid Grenades for a Grenadier to get two uses out of it or anything like that. As such, Experimental Grenades are generally best put onto Heavy Ordnance Grenadiers to maximize value, particularly your early copies, since you'll initially have plenty of Frag Grenades loaded on other soldiers.
Covers units in the blast radius with Acid, which does 1-3 damage per turn. Additionally, the blast zone will have randomly-placed Acid clouds linger inside of it, which will inflict Acid on units that take any kind of movement action inside those tiles.
The Acid Grenade is ridiculously good. Almost nothing is immune to its damage over time effect -Codices and Andromedons are it in the base game, with War of the Chosen adding Spectres and nothing else- and it has unusually high Shred at both tiers for a grenade, in fact having double the Shred of equivalent grenades. Even if you include Heavy Weapons, only the Shredstorm Cannon so much as equals the Acid Bomb for Shred, making the Acid Bomb arguably the single best source of Shred in the game, if only because it's a lot more accessible than the Shredstorm Cannon. And since its damage over time effect works on nearly everything, its functional damage profile is higher than it seems!
In the early game, when Armor is uncommon, it's actually probably the least valuable Experimental Grenade to get, particularly in the base game, as very early in the game nothing is immune to fire or Poison, Armor is rare to nonexistent, Acid doesn't have beneficial side effects, Gas Grenades have a wider radius, and in the base game Incendiary Grenades do more damage on impact. As you get deeper into the game, Armor becomes more common and individual unit Armor rises, and it becomes increasingly common for enemies to be immune to Burn and/or Poison but not Acid, making Acid Grenades more relevant and valuable relative to the competition.
Once you've acquired Advanced Explosives, the limited blast radius on Acid Bombs tends to encourage giving other explosives to non-Grenadiers, as being stuck at a radius of 3 means un-enhanced Acid Bombs tend to struggle to hit more than 1-2 targets at a time, even when they're conveniently clumped because you haven't broken Concealment yet. Indeed, I often don't bother to give Acid Bombs to non-Grenadiers unless I'm deeply concerned about the team's ability to deal with Sectopods/Gatekeepers while unable to bring a Grenadier, or at least a good enough Grenadier. Meanwhile, Gas Bombs and to a lesser extent Incendiary Bombs have a big enough blast radius that even without Grenade Launcher backing they're pretty decent at hitting groups of enemies.
One trick to keep in mind with the Acid Grenade, and indeed with all of the Experimental Grenades, is that while a direct explosion kill will prevent an enemy from dropping loot if they happened to be carrying loot, damage over time inflicted by an explosive will not. As such, tossing such a grenade at a target that will be almost killed by the grenade will fairly reliably avoid destroying the loot while still killing them with the grenade.
This does come with the caveat that you can't 100% reliably leave them on 1 HP to ensure a kill; your options are either toss when minimum damage will leave them with 1 HP, with a 20% chance you get +1 damage and directly kill them, or lob when minimum damage will leave that at 2 HP and hope the damage over time kills them. I don't understand the exact mechanics of damage over time effects, but this is really unreliable if you're not stacking multiple types, as the vast majority of the time a low HP victim will only take 1 damage from damage over time effects. (My experience is that proportion of max HP factors into damage over time, such that a max HP late-game unit will often take 3 damage and only occasionally take 1, whereas when it comes to low HP victims I have literally never seen a 3 damage roll without weird interactions from Blood Trail and whatnot) So either way this is chancy if you don't have two or three of Poison, Burn, or Acid afflicting the victim.
Also, some notes about cloud mechanics: clouds are made of a series of individual tiles, which shuffle about randomly over turns. Importantly, if a cloud moves into the tile a unit occupies, this will not inflict its effect on them, unless they specifically move: thus, if you toss an Acid Grenade close by one of your own soldiers and then one Acid cloud tile drifts into their tile, they can actually just stand there and keep shooting without being hit with the Acid status effect. Cloud-generating effects produce a somewhat randomized number of cloud tiles in random locations within the radius, and then these cloud tiles shuffle about randomly until their timer expires. Said timer is consistent across all cloud tiles: an Acid Grenade's Acid cloud will dissipate all at once, instead of gradually over time or something. I think clouds are allowed to shuffle into the same tile and so appear to disappear, but I haven't significantly tested this and may be imagining the effect. In any event, the random movement is very limited -only 1, maybe 2 tiles for each cloud tile- and as far as I'm aware there's no 'wind' mechanic and no sanity checks explicitly forcing cloud tiles to stay clumped. (That is, the combination of slow movement and short duration means you'll never see one cloud tile wander way off from the rest, so there's no need for the game to explicitly tether cloud components together)
Clouds are, it should be noted, almost never a complete barrier unless you toss out multiple cloud-producers. Units can move diagonally between cloud tiles, and cloud placement is sparser than you might expect and in particular heavily disfavors producing straight lines of the stuff. As such, their area denial potential is less great than you might expect: even in a relatively tight corridor, tossing an Acid Grenade or other cloud-producer won't usually prevent a melee enemy from running between the cloud tiles and hammering someone.
Speaking of stacking cloud-producers, clouds cannot share tiles, including that fires cannot share a tile with Poison or Acid. Furthermore, cloud tile placement is first-come-first-served: if you toss an Acid Grenade down and then toss down an Incendiary Grenade in the same area, the tiles of Acid clouds will remain Acid clouds, with the Incendiary Grenade instead filling in the empty tiles. Notably, this means that while an individual Experimental Grenade cannot be used for reliable area-denial, tossing two Experimental Grenades at the same spot will pretty reliably result in a wall of suffering most enemies refuse to run through. In theory, this should also mean that you have to sometimes pay attention to the order you toss Experimental Grenades into an area, but in practice this basically isn't true: Chryssalids are the only melee-aggressive enemy that isn't either vulnerable to all cloud types or immune to all cloud types, and they're lightning-fast and have extremely flexible movement, so trying to dissuade them with clouds is largely futile. They'll just go around, even if that means hopping on top of a building, and probably still manage to attack someone. Your own SPARKs and access to Medikits are the primary reasons to care in practice: tossing an Acid Grenade first is bad if you want your SPARK to be able to pass through an area you're going to toss multiple Experimental Grenade in, and Poison is the best cloud to start with if you have one or more Medikits equipped for ensuring your own troops will be able to walk on through.
Also, the AI is aware of the fact that movement causes clouds to afflict them, and will completely refuse to move if a cloud ends up over them when they're not already afflicted. This mostly isn't very important in normal play, since anything that creates a cloud inflicts that cloud's status effect on all hit victims, but there are edge cases where this can lead to a freshly-activated enemy standing still instead of running for Cover, such as if they're standing in a corner in a building with exactly one tile available for leaving that tile, which a cloud generated in. More likely to crop up due to a developer oopsie is that Gatekeepers are immune to fire, and yet are tagged internally to 'fear' fire: this means if you activate a Gatekeeper by chucking an Incendiary Grenade at it, it will almost certainly refuse to move because fire is in one of its tiles, it wasn't set on fire because it's immune, and therefore it's not willing to ignore fire tiles because it isn't already on fire. Never mind that the fire can't affect it. This still isn't liable to crop up often simply because you basically have to use Concealment to set such up and Gatekeepers are restricted to very late in a run, with one of their guaranteed missions basically ensuring you'll have lost Concealment by the time you reach the Gatekeeper and the other not even having squad Concealment in the first place, but if you've ever had a Gatekeeper mysteriously refuse to move, this is probably why.
War of the Chosen makes it notably more likely to crop up due to the Chosen all being able to summon minions atop themselves, which immediately perform a pod activation scramble. If you've tossed multiple Experimental Grenades atop a Chosen, they may well summon some minions, only for said minions to not move at all because they're standing inside clouds. This can make their minions easier to deal with if you're concerned you'll be overwhelmed; hurl Experimental Grenades at the Chosen to immobilize their reinforcements! (... though if they've got Mechlord this isn't very useful)
Of course, you can also deliberately produce this effect even in the base game simply by tossing multiple Experimental Grenades at incoming enemy reinforcements. It's pretty wasteful, but it's a thing you can do, and it is technically possible for this to happen organically.
Damage: 4-5/5-6 (2-3/5-6 in War of the Chosen)
Units caught in the blast radius are set on fire, doing 1-3 damage per turn and disabling most capabilities that aren't Standard Shot or Hunker Down. Additionally, random tiles in the blast radius are set on fire, which will set on fire units that move inside those tiles, and can potentially destroy/degrade flammable terrain over the course of a few turns.
Note that even if a unit can't actually be set on fire, it still takes the full up-front damage and Shred of an Incendiary Grenade, unlike Dragon Rounds contributing nothing in such cases. (To be clear, Acid Grenades will similarly do full damage and Shred to eg Andromedons, even though they're immune to Acid) Also note that units standing in water can't actually be set alight, regardless of whether they normally can or not, and indeed you can clear Burn from your own units by walking them into water if the map happens to contain a river or something. In War of the Chosen, burning units can also put out the fire by Hunkering Down, though as I noted last post enemy units lack access to Hunker Down so this change in particular is pure benefit for the player.
The Incendiary Grenade is something you have to be a bit careful about planning to use it, as the flames can spread and move in ways you didn't plan for. This is particularly important if you use Rangers and/or Templar, since they're a lot more likely to have motive to pass through the area you've made dangerous to pass through. With the right gear or skills it won't necessarily be a problem, but if you don't have those it's something to keep in mind when considering whether to use, or even bring, Incendiary Grenades over Frag Grenades.
In the base game, the Incendiary Grenade is probably the best Experimental Grenade to roll early in a run, hitting ridiculously hard up front, still Shredding Armor, and crippling many enemies by virtue of setting them on fire disabling many critical abilities, with melee-only enemies in particular suffering from losing the ability to attack at all. It's arguably better than a Plasma Grenade!
In War of the Chosen, Incendiary Grenades are shifted to more of a powerful supporting role instead of an omnieffective super-grenade: being on fire doesn't disable as many abilities (Melee-only enemies can now attack through it) and the grenade's up-front damage is slightly worse than a Frag Grenade so against targets that can't be set on fire it's actually worse than a Frag Grenade. (eg ADVENT Mecs) It's still usually more effective than a Frag Grenade, mind, but it's less dramatic and consistent, and the inability to directly smash Cover is a bit more noticeable a flaw.
And then you upgrade it to an Incendiary Bomb and it goes right back to being arguably the best explosive in the game, aside the Blaster Launcher.
Note that fire behaves kind of like Acid and Poison clouds, but not entirely. Among other points, the 'hold still and take a shot even though you're standing inside fire to avoid being set on fire' trick does, in fact, work. Usually the unit will be set on fire on the following turn, at the start of its turn, but sometimes the fire will simply go out, and even if it doesn't this can buy you a turn before the fire is a problem, which can be critical in an all-hands-on-deck situation. This is particularly useful to know about in War of the Chosen, where it's possible for a unit to end up Dazed and standing in a burning tile; moving will set them on fire, and they'll not have an action point afterward to Hunker Down, and further you probably want their help for fighting the Chosen. Putting off being set on fire for a turn can be critical to know you can do in that kind of situation.
Anyway, fire is kind of like a cloud, but in addition to actually being able to inflict its status effect on a unit that holds still indefinitely, it also slowly does damage to the environment, and unlike Acid and Poison clouds there isn't a fixed number of fire patches with a fixed timer such that they'll all vanish simultaneously. An Incendiary Grenade tossed nearby a building wall, for example, will often have the fire spread to the wall and over time punch a hole in it and part of the ceiling, even multiple turns after the originally-targeted area of ground has stopped burning.
Fires are, however, fairly restricted. I don't know the exact mechanics, but you'll never catch a corner of a building on fire and twenty turns later it's completely burned down. It'll just be a part of the building that falls apart from fire damage. I suspect there may be some absolute timer where the game keeps track of when a fire originated and snuffs out all resultant fires if they haven't gone out before that point on their own, as I've repeatedly seen cases of a building having multiple tiles clearly on fire where eg 4 tiles are still burning one turn and then the next turn they all go out, but it's possible it's a less artificial mechanic -this often also goes hand-in-hand with a significant chunk of building collapsing, so it's possible fires in buildings tend to put themselves out by virtue of destroying the tiles they were attached to while lacking mechanics to fall to the ground or otherwise jump tiles.
Also note that, as far as I'm aware, flammability of a tile or object isn't really a mechanic. ADVENT's metal-and-plastic-looking constructions don't seem to be any more fire-resistant than eg a wooden church, except in the sense that the wooden church is a frailer structure and so the fire will destroy elements of it more quickly. The only exception is that water tiles can't have fires in them. (I'm not sure what happens when eg a destructible piece of Cover is inside a river; can it be on fire anyway?)
In War of the Chosen, fire damage to the environment ticks over very specifically at the beginning of the player's turn. Critically, this means fire damage will never create a clean shot on one of your own soldiers with no chance to respond by destroying their Cover, but can absolutely do so to enemies. Notably, this is a mechanic that's true even on Legendary, even though it reworks multiple mechanics to be less player-favoring. This makes it surprisingly safe to play with fire, particularly if eg you have multiple soldiers with Fortress and/or Hazmat Vests. Just keep in mind that fire can tear the ground out from under them if it's destructible.
In the base game, fire damage instead ticks over the end of your turn, which can result in units you thought were in good Cover very suddenly being made extremely vulnerable, with no opportunity to react and correct it. I consider it a hugely positive thing that War of the Chosen changed this; technically it's a shift to a player-favoring rule, but in practice it works out to being basically fair; most AI units are pretty reliable about not moving into or remaining next to burning Cover that will disintegrate next turn, whereas the player doesn't get useful feedback on how fire damage is doing. As such, where in the base game fire damage can, with essentially no warning or ability to avoid the situation, get soldiers abruptly killed, in War of the Chosen even if you're very fire-happy it's pretty rare for the AI to end up suddenly screwed over by fire damage. There's a handful of units prone to deciding some action or another is more important than leaving burning Cover, but they're very much the exception. So this is basically just all-around better design.
Anyway, said environmental damage is interacting with the invisible environmental object HP, gradually wearing it down. Among other points ,just because something that's on fire hasn't collapsed just yet doesn't mean it won't, and it also means fires can downgrade High Cover to Low Cover if that object is coded to do that when taking enough environmental damage. This also means that if you're in a mission type where patience is fine, it can be acceptable to toss an Incendiary Grenade at a wall to burn a hole through it, such as if you're in an Avatar Project Facility, don't want to fight a pod guarding the actual entrances, and didn't bring anything that can do direct environmental damage.
Another note about environmental fires: they can actually be caused by regular weapons fire on misses. (This is part of why base-game fire damage timing is bad; you may have no idea a fire was even started) This is impractical to deliberately leverage, but it's a minor, somewhat hidden bit of utility on Saturation Fire and Kill Zone, and you should certainly keep it in mind. Among other points, if you hear terrain destruction occur just before your turn starts, you may want to check if a fire started somewhere in the direction you've been shooting, particularly if you've actually been doing a certain amount of maneuvering with an eye to the future: it may be the case that a ladder you were planning on climbing has collapsed, for example.
Finally, note that fires causing environmental damage extends to them being able to cause environmental explosives, such as cars, to detonate. You can get away with tossing a Frag Grenade such that its explosion is just barely not touching a car and then promptly running someone up against said car without worrying about it exploding, in most cases. Doing so with an Incendiary Grenade is quite likely to do terrible harm to them unless they have Fortress. So... don't do that, and in general keep an eye out for fires nearby environmental explosives before you consider using them as Cover.
... well, the actual final note is about pre-existing fires. Retaliation missions frequently have a few of these scattered about, and they're special, in that they will never spread or burn out. They will set units on fire that pass through them, and that's it. You might think it would be easy to confuse these with fires caused by enemy weapons fire in the fog, but civilians have a hidden modifier that makes it so enemies have +20 Aim when shooting at a civilian. Since civilians are usually not in Cover, you will only very rarely see enemies miss a civilian, and therefore it's actually very rare for enemies taking shots at civilians to result in a fire. Much more likely is that your own shots create fires in the fog, and ideally you're avoiding taking risky shots in the first place so this isn't a big concern.
Units caught in the blast radius are Poisoned, doing 1-3 damage per turn, lowering their Mobility by 4, and lowering their Aim by 30. This Poison can jump to adjacent units. Additionally, the blast zone will have randomly-placed Poison clouds linger inside of it, which will inflict Poisoning on units that take any kind of movement action inside those tiles.
Somewhat like Venom Rounds vs Dragon Rounds, Gas Grenades tend to be less useful than Incendiary Grenades in the base game, but it's a much more even comparison than with the Ammo Items.
First of all, the Gas Grenade's initial explosion is fully effective even against targets that can't be Poisoned. This contrasts with Venom Rounds failing to provide bonus damage in equivalent situations, and means Gas Grenades aren't literally worthless just because you're fighting Poison-immune enemies. Second, Gas Grenades have a superior blast radius to Incendiary Grenades (And indeed to all meaningfully equivalent explosives), which makes them particularly worth considering slapping into the hands of a non-Grenadier, where that +1 to blast radius can easily be the difference between being able to catch 2 or even 3 members of an active pod vs just 1 member. Third, pods being mixed means even if any given member of the pod is immune to Poison, usually it's not the entire pod, and Gas Grenades being a tool for softening up enemies is inherently synergistic with Poison's stat penalties: opening with a Gas Grenade on a Sectopod and its two ADVENT Troopers where you end up focus-firing the Sectopod and not having firepower to spare on the ADVENT Troopers means the ADVENT Troopers are a lot less likely to hit your soldiers, where with directed fire the goal is normally to completely kill the target, making it much less likely you'll get the opportunity to benefit from having Poisoned the target.
As such, Gas Grenades are actually pretty solidly good to get early in the game, particularly since enemies immune to Poison are uncommon that early. Hitting multiple enemies with Poison can also be a life-saver if you've messed up and pulled multiple pods when you're not ready -such as because you accidentally broke Concealment early- thanks to being a widespread Aim reduction. That's like a reverse Smoke Grenade, but even better! (-30 Aim vs +20 Defense, benefits your whole squad regardless of their positions, lasts longer, throws in free damage...)
Late in the game, so many of the most threatening enemies -particularly the ones you want to toss explosives at- are immune to Poison that the Gas Bomb becomes basically inferior to the Acid Bomb, particularly for Grenadiers thanks to their personal blast radius expansions tending to drown out the innate blast radius advantage of Gas Bombs, but there's a pretty solid chunk of the game they're pretty darn good. Even late in the game, they're good if you like to use SPARKs, which can casually walk through a Poison cloud unaffected but not an Acid cloud, which is especially important if you're a big fan of Strike.
War of the Chosen tilts things substantially more in the Gas Grenades favor, even with multiple new Poison-immune enemies. With Incendiary Grenades having massively lowered damage, the Gas Grenade is the more lethal option, fire disables fewer abilities, and the introduction of the Chosen provides a reliable target for Shredding that doesn't care about fire disabling abilities but does care about Poison's stat penalties.
It's still the case that the late game is pretty harmful to Gas Grenades, though. Gas Bombs are still weaker than Incendiary Bombs, you will ideally be permanently killing off the Chosen, and it's still the case that Acid Bombs should be your go-to choice for Shredding serious endgame threats. I rarely find myself able to justify Gas Bombs in the last few missions of a run, and usually if I'm bringing them it's because I've gotten bizarrely few Elerium Cores and/or had Experimental Grenades give me really tilted results like 5 Gas Grenades vs 1 each of the other two possibilities.
But it's nice War of the Chosen made things more even, and in fact is a bit impressive given how it made it happen.
Experimental Grenades is very easy to justify chancing Elerium Cores on. With only 3 possibilities, it doesn't usually take much investment to get what you want, and Gas Grenades are the only one that could be viewed as a 'dud' result, particularly once you've got Advanced Explosives, and even then only in the base game/late in a War of the Chosen run. And even then, most of the time I'm perfectly happy to use a Gas Grenade, as it has a wider blast radius than a Frag Grenade while otherwise performing the same if the target is immune to Poison (And the Gas Bomb outright hits harder than the Plasma Grenade, in addition to the blast radius advantage), so it's only if I need the terrain destruction or am worried about the resulting Poison clouds hurting my own forces that there's an actual negative involved.
I tend to go for Experimental Grenades at least three times as a result, and more if I don't get an Acid Grenade out of those first three attempts -Acid Bombs are simply too useful in the late game to do without, and it's quite unlikely I won't get them by my sixth attempt. And it's not like I can't get decent use out of spare Incendiary or Gas Grenades.
Design-wise, I like Experimental Grenades well enough as an idea, but the execution is a little weird. With only three possibilities, Experimental Grenade results across runs tend to be pretty same-y; it's stupendously unlikely you'll fail to get any result for long enough to eg not have Acid Grenades/Bombs in time for Gatekeepers and Sectopods. Furthermore, Incendiary Grenades are the only one that wouldn't be more natural as an Autopsy payoff from a base-game enemy; Vipers for Gas Grenades, and Andromedons for Acid Grenades would make perfect sense, a lot more than their current payoffs.
On the other hand, Experimental Grenades is by far the best-tuned of the Experimental Proving Ground Projects. Even in the base game, no result is tremendously lower in value than any other result, and while I consider Acid Bombs very important to have on hand in the late game they're not actually a generally fantastic tool, they're just very helpful against the most dangerous regular enemies. Every other Experimental Project has... really uneven quality in the results.
Conceptually/narratively, I think it might've made more sense to make Experimental Projects more serious of investments but also have more permanent payoffs; if an Experimental Grenade result unlocked unlimited general production of the result, or even provided an unlimited supply outright, but Experimental Grenades took longer and cost more Elerium Cores, that would both make more in-universe sense (You invent a grenade type and establish a production line, instead of having a magic one-of-a-kind grenade that replaces itself if you retrieve the body) and also open the way for the results to make runs feel more distinct. Then a run that rolled Gas Grenades first time would be very different from one that rolled Acid Grenades first time, for a long time to come. As-is, the randomness is... usually unimportant in the mid-to-long-term, and not necessarily all that meaningful even in the short term. (eg one run gets Gas Grenade and then Incendiary Grenade... in a gap where no missions happened between those two productions... making it indistinguishable from a different run that got Incendiary Grenades first and Gas Grenades second, also in a gap between missions)
I do hope that if XCOM 3 brings back the Experimental Projects idea that it takes a form along those lines. This approach isn't terrible or anything, but it doesn't live up to its potential.
Anyway, next time, we cover Experimental Armors.
See you then.