Skill

Most Operators in Arknights have skills; strong, triggerable abilities that can aid them or other Operators offensively or defensively by enhancing their stats, modifying their functionality, or giving them new capabilities altogether.

Only 3★ Operators and above have skills; 1★ and 2★ Operators have no skills whatsoever.

• 3★ Operators only have a single skill that is available initially.
• 4★ and 5★ Operators have two skills; the first is available initially and the second is available once they are promoted to Elite 1.
  • An exception to this is Amiya, who has three skills, following the same mechanics as 6★ Operators (see below).
• 6★ Operators have three skills; the first is available initially, the second is available once they are promoted to Elite 1, and the third is available once they are promoted to Elite 2.

Operators with multiple skills can only choose one of them to be used at a given time, which is done from the Operator or squad menu.

Generally, the first skill is a generic skill shared across all Operators of the same class and/or branch, while the second and third skills are unique to each Operator and often act as core to the Operator's playstyle.

Usage

Skills are activated in two different ways, both of which requires it to be charged by having enough Skill Points/SP and have valid target(s) to be present within the skill's range if it requires one:

• Auto skills are immediately activated as soon as they are charged.
  • Some Auto skills requires a condition related to the skill's effect to be met for it to be activated. For instance, most Trapmaster Specialist's skills will only be activated when the count of their respective trap is not at maximum; if the count is topped off, the skill will be charged but not activate until the trap's count is reduced by deploying one.
  • On the same note, Flametail's Quick Intuition and Vigil's Packleader's Gift will not be activated if she/the Wolfpack still has the buff from the previous activation, hence, until Flametail takes a Physical attack (and dodges it) or the Wolfpack attacks an enemy, Quick Intuition/Packleader's Gift will charge but not activate.
• Manual skills are activated on the player's command, by tapping on said skill's icon in the HUD when it is charged.
  • Certain Manual skills also requires a condition related to the skill's effect to be met for it to be activated.
  • On the same note, Push Stroker/Hookmaster Specialists cannot shift enemies with their Manual skill if there are no enemies within their range. If an enemy is blocked behind the Specialist's range, they will be within the latter's attack range, but not skill range. Certain complex stalling strategies actually makes use of this quirk, as activating the skill will interrupt the Operator's attack.
• Passive skills are active at all times with some being context-sensitive.

Few skills, notably those making use of the Ammunition mechanic, can be deactivated by tapping the skill's button on the HUD while the unit is selected and the skill is active, ending it prematurely. Guard Amiya's Ying Xiao - Shadowless, Silence the Paradigmatic's Dreadnought Protocol, and Sussurro's Deep Healing can only be used a certain times in an operation; once the skill expires after its usage limit is reached, it cannot be charged anymore.

Most skills last for a short duration, but some skills last for an unlimited duration (actually for sufficiently long period to be functionally unlimited in most cases, see Trivia for details). Despite not being unlimited, skills with instantaneous effects (e.g. Power Strike skills) are treated as if their duration is unlimited. Skills making use of the Overload mechanic have additional effects and certain drawbacks when the skill's remaining duration is at most half of the total duration.

Some skills, usually Auto ones with instantaneous effects, can store multiple charges; while the skill is immediately usable after it is charged, the Operator can still charge it and stores additional uses of the skill up to a limit.

Upgrades

All skills start in Level 1 and can be upgraded through 6 additional levels from the Skill Upgrade menu on each Operator's Character Details page. Skill upgrades apply to all of the Operator's skills if they have multiple skills and requires the following:

Level	Skl. Sum.	Material(s)	Requirement(s)
	1	–	–
	2	Few T1 upgrade materials
	1	Few T2 upgrade materials
		Few T3 upgrade materials	Promoted to Elite 1
	2

Level	Skl. Sum.	Material(s)	Requirement(s)
	2	–	–
		Some/few T1 upgrade materials
	3	Some/few T2 upgrade materials
			Promoted to Elite 1
		Some/few T3 upgrade materials
	4

Level	Skl. Sum.	Material(s)	Requirement(s)
	4	–	–
		Some T1 upgrade materials
	6	Some T2 upgrade materials
			Promoted to Elite 1
		Some T3 upgrade materials
	6

Level	Skl. Sum.	Material(s)	Requirement(s)
	5	–	–
		Many T1 upgrade materials
	8	Many T2 upgrade materials
			Promoted to Elite 1
		Many T3 upgrade materials
	8

Specialization

Once the Operator's skills are at Level 7, they can be further improved to three additional levels through the Specialization training function, or colloquially known as Mastery training by the community. Only 4★ Operators and above that have been promoted to Elite 2 can undergo Specialization training.

Specialization training is done at the Training Room of the RIIC. The process takes time to complete (which can be accelerated by assigning certain Operators as trainers), and unlike skill upgrades, are done individually for each skill.

Specialization training requires the following:

Level	Skl. Sum.	Materials	Time	Requirements
	2	Some/few T4 and T3 upgrade materials	8 hours	Level 1 Training Room
	4	Some T4 upgrade materials	16 hours	Level 2 Training Room
	6	Some/few T5 and T4 upgrade materials	24 hours	Level 3 Training Room

Level	Skl. Sum.	Materials	Time	Requirements
	5	Some T4 and T3 upgrade materials	8 hours	Level 1 Training Room
	6	Many/some T4 upgrade materials	16 hours	Level 2 Training Room
	10	Some T5 and T4 upgrade materials	24 hours	Level 3 Training Room

Level	Skl. Sum.	Materials	Time	Requirements
	8	Many/some T4 and T3 upgrade materials	8 hours	Level 1 Training Room
	12	Many T4 upgrade materials	16 hours	Level 2 Training Room
	15	Many/some T5 and T4 upgrade materials	24 hours	Level 3 Training Room

Tips

Specialization training is very resource and time-consuming, especially for 6★ Operators. Thus it is important to know how significant the boost to the skill will be and whether or not it is worth farming the materials for.

Trivia

• 1★ and 2★ Operators have skill activation dialogues, but these went unused due to the obvious fact that they have no skills.
• Skills with unlimited duration are not actually permanent, but has a very long duration of 3600 seconds, or a whole hour. On average, Arknights operations are cleared in 5–8 minutes (10–15 minutes for Annihilation), which is much shorter than the duration and thus unlimited skills rarely, if ever, expire.
  • One of the few instances where it is actually possible for unlimited skills to expire is Research Base Quarantine Zone during Pinch-Out Experimental Operation; enemies there can have about 2.5 million HP and high enough defenses that most Operators barely damage them, resulting in the operation going for over an hour.
  • Even if unlimited skills do somehow expire, most of them actually applies the effect to the subject permanently although it does not stack should the skill is activated again aside from certain effects such as the Unit Limit increase from Command Terminal.