Arknights: Rosa in-depth analysis

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Hello again! With what looks to me like a surge of attention to Rosa due to chapter 8’s presence (especially the drones), I figured that it’s a great time to talk about her (at least when I first write the post, I am pretty late with my plan because of CC#3). And Rosa certainly has an amazing kit going for her, opening up many other different strategies for the unorthodox doctors out there to play around.


Rosa is a unique sniper (Heavyweight Sniper) that functions a little bit differently to most other sniper (just not as different as Rosmontis). She prioritises heavy enemies, and then ignore a large portion of their DEF, of which they tend to have a lot. Her best and most well-known kit is a multi-target, long duration bind over a massive area with a relatively short cooldown. This makes her one of the best units to stop enemies’ advance where your “delete button” units can’t rotate their skill fast enough or are busy somewhere else.


Offensive stats

Rosa, or rather, her archetype, has amazingly high base ATK stat, rivaling that of the Wide Range Sniper (which is the highest ATK archetype in the game before a new upcoming Caster archetype), albeit losing to them slightly. Despite that, their ATK rate is noticeably better than the Wide Range Sniper at 2.4s per attack instead of 2.7s.

For a Single Target unit, it's actually not that great. But as always, it's mainly their skillset that makes an operator.

Defensive stats

You’d think she’d have weaker defensive stats because of the higher offensive stats, but not quite. Her HP is on the higher end of all the Sniper, losing only to the Boomstick Snipers, Rosmontis, Schwarz, and Andreana (a +HP trust cheater). I said “not quite” because her DEF is god awful and is one of the worst of the snipers (but Snipers in general don’t have high DEF aside from the short range one and Rosmontis). She also has no RES like most other Snipers.

Although, her defensive stats don’t truly matter because of her massive range, which I will be getting into soon.


Rosa’s cost is especially high for a ST unit: starting at 22 DP cost, and ending at 24 with E1. This make her the highest DP cost for a ranged ST unit.

Range, Trait, Talent


Rosa’s range is massive, but also weird. She has a massive range in front of her, but she cannot attack enemies close to her.

Rosa's range at base (left) and at E1 (right)

Rosa is the only one so far to be able to consistently reach that corner of her range on the side and it’s more important than it sounds. Personally, since the frontal range is the same as a normal AoE Sniper, I focus more on those side range so they don’t compete for space (but I also use AoE Snipers a lot). The large width of her range also allows her to cover multiple lanes at once, or just to cover a long stretch of lane (a sideway Ifrit so to speak), both of which are great for Rosa since she can have more room to use her skills.

The lack of close range can be an issue sometimes, but 90% of the time it won’t impact her effectiveness that much. Basically it forces you to either put her further back, or to shift the front line forward. In either case, she will be safe behind other operators while providing great cover for them.

In fact, if you’re cheeky enough, you can even use the lack of close range to your benefits, like this in DM-EX-6, where she can ignore the flag guys in the middle but also gaining bonus damage from the vent. But that’s a pretty small quirk and the event will take a while to return.


Prioritises heaviest enemy in range.

Before Rosa, enemy’ weights are only important to the Shifter, where they shift enemies based on the difference between their Shift forces and Weight. Now it’s important to Rosa (and a future operator) to decide who Rosa will attack first.

Luckily, enemy’s weights are all in integer, ranging from -1 to 10 (ok I mean there is one with weight 99 but…). So it’s easy to compare them together and know who Rosa will attack first, and if they are the same weight, then the normal priority is applied (least path left to blue box).

This is actually really good for Rosa, given the effect of her talent coming up next.


First talent: Bone Piercer

Available at E1: When attacking heavy enemies (weight >= 3), ignore 40% of their DEF.

At E2 it increases to 60%.

In a way, this talent sounds limiting, because she can only ignore DEF of higher weight enemies. But in reality, the higher the enemies’ weight, the higher DEF they tend to have. All of the Defender-type enemies have weight 3 and above. Which means, when the talent gets to work, it works extremely well. There is one exception (because there is always an exception): the Rockbreakers, who have at best 100 DEF without any CC risks. But then again that just means they take a lot of physical damage to begin with and need no DEF reduction.

That means, with her high base ATK, and now a talent that ignore a massive portion of DEF towards the enemies that have a lot of them, Rosa can deal with most high armored enemies without needing to look for an arts damage source. I said “most” because there are occasionally some decently high armored enemies that are at weight 2 (especially with Contingency Contract risks).

This also allows her a certain reputation as a boss focus unit, mainly because most bosses have weight 5 and above. So Rosa would prioritise boss in those cases, since all non-boss enemies have up to weight 4. The bosses that aren’t heavy is the number 1 boolied boss in the game, and normal Mephisto who’s teetering at weight 3. I personally don’t consider her a boss killer specifically, but she’s a great opportunity maker to kill bosses and can also contribute massively in damage.

It’s also pretty easy to recognize who’s heavy, because they also tend to look bigger than the rest. All big looking enemies are usually weight 3 and above, exceptions being Sarkaz Caster/Swordman and Fanatic (drunk hammer guy in CoB/Transport Hub).

You may think this is counterproductive with Angelina S3, which reduces enemy’s weight. It’s actually much less of a concern than you’d think. First, since it’s a global effect, it won’t change Rosa’s current attack priority. Second, the only weight level that is affected by this is weight 3, and they rarely have high RES. Guess what Angelina S3 does? That’s right, a 5-targets, massive area, AND massive arts damage. Third, Ange’s S3 is manual activation, meaning you can choose when to use it. While that does mean you need to spend more work to fit those skills together, the first 2 points help offset that a little bit, so you don’t have to worry about it that much. Plus using Angelina normally already required a bit more calculations than usual, so it’s not like you need way more than before by adding Rosa to it.

Second talent: Ideal Student

Available at E2: When in team, all Ursus Student Self-Government members gain +8% ATK.

This is one of the few talents that works without needing to be deployed, but the effect is pretty not noteworthy. It only affects 4 operators so far (HG gib Leto): Zima, Istina, Gummy, and of course Rosa herself. Out of those 4, only Rosa can make great use of it with a really high base ATK, while the rest doesn’t have a high base ATK enough to make 8% meaningful (but obviously more ATK is always nice).

While Rosa loses out to Firewatch for base damage, this talent put her over FW finally, but I supposed it’s not a fair comparison.


RIIC Skills
  • Always available – Student Council President:

When in the Control Center, decreases morales consumption for all operators in the CC by -0.05/h for each Ursus Student operators in it.

The group effect is actually not that great. It’s the same as Ch’en CC skill, but affecting the one that are generally more needed elsewhere. Gummy with the amazing Trading Post skill, Istina to get clue 4 (it used to be rare when I first wrote the post, but now we also have op like Absinthe), and the only free one left is Zima, who has a dorm buff to regenerate morale faster after working with Rosa in the CC, if you choose to use this base skill.

The base skill itself is also not that great, synergy aside. It only affects the morale consumption of the one in the CC itself, not everyone in the base. Which means that it only prolongs their work shift in the CC, so it only works better for people who only check the base once every 2 days (if you have 5 people with this skill, they lose 12 morale after 24h). I think it’s safe to assume then that this skill isn’t that great. At least with Ch’en, you can combo it with Swire and Hoshi whose other base skills doesn’t really get used most of the time, but then again Ch’en’s other base skill is also much, much better (I mean if you E2 her which I assume you didn’t).

  • Available at E2 – Prestige:

When in the HR Office, increases speed by 20%. Additionally, for every 1 contact made, increase chance of getting clue 4 (Ursus clue) in the Reception Room. (working time and recruitment slot improves the chance).

I still don’t know the exact details of this, and it’s actually really weird. We can safely assume that she gives more chance to get clue 4 as she finds more refresh tag. But it also said “working time and recruitment slot improves the chance” so that means the longer she works there, the more chance she’ll give clue 4? Does it add to the amount of chance that she gets from getting a refresh, or does it add separately? Then recruitment slots also affect it, which means HR level is also important (the same importance to Whisperain, for example). But do the slots innately give her more chance as well, or it also has to wait for Rosa to find a few refreshes?

Overall, it’s a bit too vague, and that was before we can even ask about the exact chance it improves to get clue 4. But if you’re lacking clue 4, this could be an option I guess.

The "best" part of this base skill is that a major identity of it is from Rosa getting a refresh, but the speed increase is only half of the normal accessible one (+20% instead of +40%), which reduces the rate of which Rosa get a refresh.

First skill: ATK Up γ

Stats at level 7

ATK +60%, 30 seconds duration, 35 SP cost, 10 initial SP, Auto Recovery, manual activation


Please don't.

Advanced Details

Uhhh… Rosa has a really high base ATK to get a lot from +60%?

Possible usages

When you forgot to E1 Rosa or switch to her second skill in a squad before starting a mission with her.

Second skill: Split Shot
fast explanation

Stats at level 7

ATK +60%, attacks 2 targets at once, 60 seconds duration, 80 SP cost, 45 initial SP, Auto Recovery, manual activation.


M3 gives ATK +90%, 65 SP cost, everything else unchanged.

Advanced Details

This skill has the same ATK +% with her first skill from level 1 to level 7, and coupled with the fact that this skill let her attack 2 targets at once and has near-similar uptime, means that you are 99% never going to need S1.

Do remember her massive range, attacking 2 targets at once in this case has more significant to it than say, Blue Poison. She can cover nearly the entire battlefield, to exaggerate, so taking 2 enemies at once allows her to contribute to the battlefield a lot more than you’d think even if you already have big burst DPS unit like SA, Surtr,…Though it definitely feels overkill sometimes, so just wait for her third skill.

Before, I was pretty dismissive of this skill, because I thought we have too many sources of mass DPS, especially coming from a 6*, but what Rosa can give with this skill is still unique/special enough that it does warrant not being ignored entirely, even if her third skill coming up will be better on her 90% of the time (at least in my opinion). Also because of the amount of high weight high DEF enemies in Chap 7 and 8 I guess.

Personally I prefer a shorter duration if it means similar uptime, i.e. 30s duration 40s cooldown over 60s duration 80s cd, but both has its own merits, and it’s just my preference.

Possible usages

The 1-minute duration is very nice, but the just as long cooldown afterward can feel anemic at time. So it means that, while the skill can cover like 2 or 3 waves in 1 cast, it will also probably be down for just as long afterward, making it just as much as a 1-time skill (or retreat and redeploy). And before M3, the downtime is pretty massive.

But do remember her entire kit so far: massive range, prioritise heaviest, ignore DEF of weight 3+. And then add that with this skill granting a large ATK boost (which she also has a high base ATK), and 2 targets, mean that she can actually take care of those defender-type enemies, but also can clear mobs normally, but also also can kill boss (because again they tend to be heavy). It really does a lot of damage and capable to deal with many types of enemy.

The real issues of this skill, are first, again, the cooldown, where you might even have to retreat (before the skill even ends) and redeploy just to get the skill back up faster, and second, the existence of her third skill, which is just an amazing skill altogether.

Third skill: Avalanche Breaker

Stats at level 7

ATK +10%, find 3 heaviest enemies in range, binds and attacks them once per second, 7 seconds duration, 34 SP cost, 12 initial SP, Auto Recovery, manual activation.


M2 gives +20% ATK, binds 4 enemies, 32 SP cost, 14 initial SP

M3 gives +25% ATK, 8 seconds duration, 30 SP cost, 15 initial SP

Advanced Details

It’s pretty easy to miss this, but the abysmal %ATK boost is offset by the “attacks once per seconds” which effectively boosts her attack rate by 2.4 times. It also doesn't get affected by attack slow or attack speed either, and will always hit once per second if the skill is on going. That’s a massive burst of damage during that 7/8 seconds. And by M3, it’s 125% of Rosa’s ATK per second for 8 times, and that’s by no mean a small amount of damage.

Bind is a great form of crowd control, and while binded enemies can still attack, with how large Rosa range is, she can easily reach someone and stop them far from ever reaching your other allies. Another argument is no enemies are bind-immuned (without risks) while some are stun-immuned, making her bind almost always works when you need it.

This skill might have a great stopping point at M2, making her bind 4 instead of 3 enemies, but I advise go all the way regardless because the bind duration is more important, plus lower cooldown means you get to spam more, meaning you have more chance to stop enemies. Plus it also has a faster first use after you deploy her, for helidropping or just to quickly get her skill ready.

Binding for 8s sounds mediocre, but this skill has the second longest 1-instance (some people call this “gapless”) non-sleep crowd-control in the game. The longest is Eunectes' S2 18 seconds stun. Mostima has 7s stun, and Manticore has 5s slow (just refresh indefinitely if in range), Magellan has 5 instances of 2.5s bind, but with a 0.5s gap in between. Blemishine has 10s of sleep, but it’s sleep, so it doesn’t jive well with others, while Rosa’s bind (and Eunectes' stun) is just too good at helping others doing more work.

There’s a small time for the bind to actually hit, basically from when she fires the harpoon to when it hits the enemies. Most heavy enemies are slow, but if you’re using it to stop fast enemies (e.g. Lancers, enemies with MVM SPD risk,…), that’s an important point to consider. It will still bind and damage enemies even if they left her range, so just need to aim for them at the moment of casting the skills.

Possible usages

There are just so many ways to use this skill, and I love it for that. My favorite joke is that “Rosa appears more in my squad the less melee units I have” and it’s still technically an understatement on how great she can be.

The most basic is as a burst/nuke damage to 4 targets, sometimes it’s enough to let things die faster, especially the high DEF one (which are usually heavy). It has relatively low SP cost for this job too.

The skill is my personal replacement for Gravel. For example (PTSD warning), Twilight of Wolumonde with the Shaman. The easy cost-effective solution is to use Gravel + a Slow Supporter to let them die away from the Gramophone/your squad. But with Rosa, I just use her skill when they show up and they’ll die where they are binded. Shamans have weight 3 so it’s even better. Another example is the Lancers from Darknight Memoirs, these guys aren’t heavy, but if they touch your non-defender melee, they are pretty much gone, so stopping them with Rosa is also great. The better part is Gravel without skill is useless and is out of the battlefield, while Rosa’s basic attack can still do something significant. Gravel’s 14s redeploy time may account for something better than Rosa’s 30SP cost, but most of the time the enemies won’t appear that frequently (especially in the 2 examples I gave). Gravel can only stop 1 enemy, while Rosa can stop up to 4.

Essentially, her massive reach allows you to stop enemies before they reach your allies, and that’s nothing to scoff at. The only thing Gravel can do that Rosa can’t is baiting ranged attack (Faust, Talulah,…), plus Gravel is pretty much accessible by everyone, while Rosa is a 6*. And I’m NOT dissing Gravel btw, just trying to say that if you love Gravel because of what she can give you, you may also be interested in Rosa as well (assuming you have her, of course).

Another great way to use the bind is to allow more time to let other allies to do more damage that they otherwise couldn’t. Especially if they have a really really strong skill but is balanced by having weird range, some even has a straight range. You must have heard/saw the strat in CC#1 that let Rosa bind Crownslayer in the middle of 2 tiles and let Schwarz and Bagpipe to hit her with their 1-width tile in different line.

Do remember that, despite targeting heaviest enemies first, you rarely face too many heavy enemies at once, so you can still bind the lighter one (e.g. the Lancers again). When there are multiple enemies with the same weight, it follows the normal priority again, so you can still somewhat predict who it will bind.

Don’t feel like you have to wait for 4 enemies in her range to bind. If there is an extremely dangerous enemies to stop but no one else is in her range, just stop them first. You may lose 75% of the potential damage, but you also save your team and your sanity.

My favorite record of this skill is to completely replace Angelina and Suzuran in CC#1, the 2 that were considered queens of the map, giving me this CC#1 Risk 19 Week 1 clear (I probably can push 20 if I reduce squad size and switch to bursting CS twice I guess, but the point stand). Another example is my CC#2 Day 10 New Street max risk (super speed day), where I just use her to stop the throwers to be killed by Firewatch and occasionally some Berserkers too. A few smaller examples are my R8-10 with 2 Snipers and CB-EX-8 with 4 Snipers, where Rosa’s role is simply to both kill the big guy and to stop the rushing guys (both the 2-block lance guy and the bulldozer) from advancing.

All are techniques that I have listed above so you can see what I meant, and there is one more great clear below too.

Closing Thoughts

Focus mostly on her third skill and obviously mastery it if you find the needs to. Her S2 isn’t bad either, but it’s not as good because her third skill is just more flexible.

Don’t worry too much about her range, it may be awkward at first, but if you got used to it, it’ll be much better (though that applies to anything I supposed). The 

There is a future 5* unit that is the same archetype as Rosa, but they work too differently to each other that I don’t think it’s worth worrying about her yet, though I shall see how that goes when she shows up. With those two together, they can even do this amazing R8-8 duo snipers clear

My favorite ally with her (aside from Ely of course) is mainly Schwarz, because her S3 has a narrow range. I also don’t use that strat much, even in a lot of my ranged only clear. Rosa just synergizes with too many non-melee ops that I can’t decide, and Schwarz just benefits the most because of her awkward range, the same goes for Ifrit (but I hate casters, so she goes down 1 rank xD).

Fluff: Rosa’s S3 is extremely similar to Cliffheart’s S2 in many ways. It also throws sharp weapon attached to ropes to 3 enemies over a large-ish area to inflict DEF-ignored damage and inflicts crowd-control with a relatively short cooldown. But that’s enough meme I guess.

For those that have Rosa, how do you find her? For me, certainly she is nowhere “niche” that people tend to claim (the claims that I saw), but my playstyle as a whole is too unorthodox for me to ever try to dispute those claims. Admittedly, her binds aren’t really needed if you have either strong defenders or are capable of killing them with ease already.

Anyway, thanks for reading, and I’ll see you next time.

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About the Author(s)

Random pleb Arknights guide writer on reddit