Guide: Stationary Security Service

From Arknights Terra Wiki
Jump to navigation Jump to search

A comprehensive guide for Stationary Security Service.

For this guide, "{no} {class} (A/B)" (e.g. "5 Guard A") will be used to designate specific Tactical Equipments.

General tips and strategies

  • Try to raise the Operators that are to be used as high as possible (preferably to at least Elite 1 max. level and with the skill level of 7) to lessen the difficulty the player might face.
  • Remember that the player can borrow others' Support Units, but it must be done during initial recruitment; Support Units can no longer be recruited afterward!
  • It is recommended to ensure that the number of Operators from each class are balanced.
    • If this is not possible, try to recruit the missing Operators after clearing operations.
    • However, for players who understand their team and know the core Operators they would be using to clear stages, they have the option to fill their squad with only Operators that grant certain, desired Tactical Equipments to buff their core Operators. For instance, running Goldenglow as the main Arts DPS needs either 3 Snipers + 2 Casters or 4 Snipers + 1 Caster).
      • While this strategy is effective, it must be noted that some of the Operators being relieved must also be strong, in case the player does not transfer their desired core Operator early.
      • One also have the option to fill their squad with more relieving Operators, given the initial squad size is 20.
      • It is also recommended to have more than just one core DPS Operator, given the large beginning squad size for this strategy.
  • Due to the relieving mechanic of S3, sometimes it is not necessary to have all the Operators at higher rarity. Low rarity Operators can be used as "fodder" to boost Tactical Equipments.
  • Do not fret if one fails S3 operations more often than completes them! Unlike in Integrated Strategies, failing an S3 operation does not compromise the entire mission, so every failure can be a lesson and experience that allows one to be more familiar with the operation.
    • In fact, S3 operations can become more difficult to complete as time passes; at the highest possible Danger Level of 20, enemies will have as much HP and doubled ATK/DEF, not to mention that the core and/or fodder Operator(s) may not be available when needed, so quitting out of an S3 operation (especially the LT-4 and LT-8 ones) and retrying it if things aren't going well is advised.
    • There are secret medals that require the player to complete an entire S3 mission without quitting out or failing any operation, which can be easily achieved if the player has high-level Elite 2 Operators and use correct strategies.
  • Make good use of Tactical Equipments! The Equipment buffs are the only way to offset the Danger Level mechanic in S3, so players should learn about the effects of each Equipment and which Operators benefit the most from them.
  • Adapt with the S3 operations and enemies. Since S3 operations are fixed, players should know them well to clear them as efficiently as possible. The EC Units are helpful as well but Special ones are only awarded at the LT-3 operation by beating the bonus enemies, hence one should know their strengths and weaknesses to find the most efficient way to defeat them.
    • Arts damage is highly preferred since the Danger Level mechanic do not increase RES in any way, thus enemies are just as vulnerable to Arts damage as they would normally. Against enemies with high RES, make use of RES debuffs or ignores to counter them.
    • Ranged enemies are rare in S3 operations, so ranged Operators (especially Casters and Supporters) would be invaluable. Of the S3-exclusive bosses, the only ones capable of harming ranged units are Spherical Colossus (due to its damaging aura) and Nature's Compromise (with its Deciduous Hormone special attack).
  • Relieve Operators instead of retreating them! If an Operator is retreated, whether manually or for being downed for too long, all of the Tactical Equipments on them will be lost, so players should avoid doing the former under any circumstances and relieve them instead. If an Operator has to be retreated however, make use of Emergency Recall Boxes or Specialists with Tactical Equipment A which would allow the retreated Operator to retain their Equipments.


  • When choosing Temporary Reinforcements, prioritize Operators of the following class, from the highest to lowest: Supporters > Specialists > Vanguards.
    • Supporters will help in getting Operators into the Deployment Waiting Zone quickly due to their Tactical Equipments, and can be useful to get the necessary fodder Operators.
    • Specialists with Tactical Equipment A can retreat an Operator and return them into the Waiting Zone instead of taking them into the Recuperation Area, which can help in building buff stacks and in saving a downed Operator.
    • Vanguards with Tactical Equipment A are useful in the early game where DP is tight and can help in enhancing melee Operators.
  • When choosing EC Units, prioritize the following units, from the highest to lowest: Equipment Activation Valve > Preparation Area Transmitter > Emergency Recall Box > Recuperation Area Transmitter > Reassignment Transmitter.
  • Due to the low deployment limit in S3 Operations, it's not recommended to use Operators with summons that were counted into unit limit, since they will be unable to perform at full effectiveness. This includes all Summoner Supporters, Phantom (Phantom in the Mirror) and Kal'tsit (Mon3tr).
  • The greater the Danger Level, the tougher the enemies get. Because of this, it's not advised to use Operators with low Block Count or Operators that only attack one target at a time. Instead, Operators with AOE potential are recommended in S3, especially Operators that deal Arts damage.
  • For Operators with skills with multiple charges (such as Eyjafjalla's Ignition, Ifrit's Pyroclasm, Passenger's Glorious Shards, etc.), it is recommended to have them inherit Tactical Equipments that provide SP to increase the frequency of skill usage.
  • For Operators with skills with unlimited duration (such as Blaze's Chainsaw Extension Module, Thorns's Destreza, Fiammetta's "Reponite", etc.), it is recommended to have them inherit Tactical Equipments that increase ATK to further increase their damage output, with some Tactical Equipments that provide SP or Ptilopsis as support to charge their skills faster if necessary.
  • For Operators with skills that deal high Arts damage (such as Surtr's Twilight, Carnelian's Mark of Gluttony, Dusk's Flowing Ink, etc.), it's recommended to have them inherit Tactical Equipments that increase ASPD to further increase their damage output.


Because of the randomness in S3, it's not recommended to have several Operators to inherit many Tactical Equipments. However, there's some of them that we highly recommend if the opportunity presents itself:

Operator Description
Eyjafjalla's Volcano (S3) proves to be as useful as before, even more so after with 3 Sniper A + 2 Caster A (to compensate the skill's high SP cost), Volcano can be used much frequently, allowing Eyjafjalla to burn most of the enemies to ashes quickly.
Gnosis' ability to inflict Cold (and eventually Freeze) will prove to be very valuable, allowing him to stop enemies dead in their tracks and leave them vulnerable to other Operators, especially due to Rigid Ice's second effect of inflicting Fragile to Cold/Frozen enemies within his range. Have Gnosis inherit at least 4 Sniper A, and watch as he "perma-Freezes" enemies that stray into his range, which can be very helpful against bosses and bonus enemies! Do note that some S3-exclusive bosses are immune to Freeze, so it'd better to use Suzuran against them (see below).
With no less than 5 Sniper A, Goldenglow becomes an "Arts machine gun" with Surging Current (S2) or Crystalline Shine (S3) who can swiftly take out most enemies with a combination of her talents to both deal splash damage on occasion and ignoring some RES. Do note that even with 4/3 Sniper + 1/2 Caster A, Goldenglow will still perform just as well, with a little bit of higher ATK and also slightly better skill uptime.
Horn's high base ATK, being a melee unit and using ranged AOE attacks mean that she can not only bombard enemies from a distance, but she can block them and let others or herself to defeat them if necessary. With at least 4 Guard A, she can be a literal artillery cannon that unleashes hell to whoever in her range. All of Horn's skills can be used for various scenarios, but her Ultimate Line of Defense (S3) is more recommended when facing elites and bosses.
The Shields provided by Mudrock's Ward of Fertile Soil can help her tank strong enemies, who will inevitably have their ATK increased to sheer levels to OHKO most weaker Defenders; her Unshakable Solidarity will also prove helpful to withstand attacks from Sarkaz enemies. The best course of action is to have Mudrock use Crag Splitter (S2) and inherit at least 2 Defender A + 1 Vanguard A, and preferably supported by at least two Medic Tactical Equipments A, Bard Supporters, or Perfumer.
With no less than 5 Caster A, the once-weakest 6★ Operator has now ready to place his judgment on his enemies by unleashing Glorious Shards (S3) roughly every ten seconds, not only slowing down their movement but also burst down weaker enemies in an instant. Do remember that his Operator Modules are recommended for this to work better.
The Corrupting Heart scales off of ATK, and with Wish of Burial Beyond the Light (S2), she can act as a substitute for Medics while simultaneously buffing friendlies' ATK and DEF. It is recommended to have the Corrupting Heart inherit at least 1 Caster B as this makes her healing and Wish of Burial's ATK buff more potent, but she is still viable without it, as she benefits from all ATK buffs, so Caster A can work well with her as well. Her Skadi's Seaborn can be used to project her aura to friendlies outside her reach.
With Childhood Frolic (S2) and at least 3 Sniper A, Suzuran can "perma-Slow" enemies as well as inflicting Fragile on them due to her talent Binding Circle, making her a solid replacement for Gnosis, especially against enemies that are immune to Freeze.
As everyone's favorite overworked uncle, Mlynar greatly benefits from both ATK and ASPD buffs feeding into his Unbrilliant Glory (S3). The two recipes to really get uncle cooking are either 5 Vanguard A or 4 Vanguard A + 1 Guard (for even higher damage). Afterwards, one may simply activate the skill whenever it is available and watch as he forces his enemies into early retirement.
SilverAsh functions largely the same as Mlynar, but being a Lord Guard rather than a Liberator, he has more freedom with his build: specifically, he can inherit 5 Vanguard A for better damage and better uptime which is also something that Irene performs exceptionally well with, given her Judgement (S3) both plays into her DEF-ignoring talent and deals significant damage on top of that.
Although both Lock of Shattered Time (S2) and Key of Chronology (S3) benefit from 5 Caster A, she truly shines through with a maxed out Module, paired with Key of Chronology, allowing her to deal high AoE Arts damage and slow all enemies within her range by a staggering 90% (99% at Potential 5), allowing for easier wave management against a horde of enemies and providing some decent stalling utility to keep drawing Operators and inheriting Tactical Equipments while her skill is active, and because she's buffed by 5 Caster A, the uptime for Key of Chronology is significantly better than elsewhere.
Already a loud man himself, Chongyue becomes even louder now! Jokes aside, with Anatta (S3) and at least 3 Guard A, he can literally spam the skill and temporarily become a multi-targeting, AOE-attacking Guard who can fold his enemies left and right with more consistent activations of An End to War.