Guards have high HP and ATK which gives them high DPS output. They often have good synergy with the other classes, especially Defenders who can block enemies to be pummeled by Guards or with each other to deal even more damage with coordinated attacks.
The Guard class is divided into ten branches: Dreadnought, Centurion, Lord, Arts Fighter, Fighter, Swordmaster, Musha, Instructor, Liberator, and Reaper.
Dreadnought Guards (Chinese: 无畏者; Pinyin: Wúwèi zhě; lit. "Fearless [Guard]"), formerly known as ST (Single-Target) or Duelist Guards, have the highest HP and ATK of all Guards, but have the lowest DEF and can block only a single enemy.
Dreadnought Guards excel in dueling enemies, especially those with high HP and low DEF like bosses.
Centurion Guards (Chinese: 强攻手; Pinyin: Qiánggōng shǒu; lit. "Striker [Guard]"), formerly known as AoE (Area-of-Effect) Guards, can block up to two enemies, which is increased to three once promoted to Elite 2, and their attacks hit multiple enemies equal to their block count. Centurion Guards have average-high HP and ATK, and average attack interval, but their DP cost is the second highest of all Guards.
Centurion Guards are effective in dispatching hordes of enemies and stalling powerful enemies.
Lord Guards (Chinese: 领主; Pinyin: Lǐngzhǔ; lit. "Lordmaster [Guard]"), formerly known as Ranged Guards, have a ranged attack which allows them to damage approaching enemies before they are blocked and are capable of targeting aerial units; this ranged attack deals 80% of the Guard's base ATK.[note 1] Lord Guards have average overall stats and DP cost, and can block up to two enemies.
Lord Guards are quite versatile for every situation since they can also provide support for Vanguards and Defenders, or take down aerial enemies should the opportunity present itself.
Arts Fighter Guards (Chinese: 术战者; Pinyin: Shù zhàn zhě), formerly known as Arts Guards, are identical to Dreadnought Guards, but deal Arts damage instead of Physical damage. This makes them effective against enemies with high DEF but inefficient against enemies with high RES, and possesses innate RES in return for a higher DP cost.
Fighter Guards (Chinese: 斗士; Pinyin: Dòushì) are similar to Dreadnought Guards, but sport a very low attack interval, allowing them to deliver large number of hits in a short time which makes them an excellent option against enemies with low DEF, and a lower DP cost – one of the lowest of all Operators – that allows Fighter Guards to be deployed early in the game, in exchange for a low ATK to offset their high attack rate that makes Fighter Guards highly ineffective against enemies with high DEF.
Swordmaster Guards (Chinese: 剑豪; Pinyin: Jiàn háo), formerly known as Dualstrike Guards, deliver two hits in one attack, essentially doubling the damage they deal, with an average-low ATK and block of up to two enemies.
All Swordmaster Guards' skills have offensive SP recovery, but even though their attacks hit twice, it is still considered as one attack, thus Swordmaster Guards only gain 1 SP in each attack as usual.
Musha[note 2] Guards (Chinese: 武者; Pinyin: Wǔzhě; lit. "Warrior" [Guard]"), formerly known as Enmity Guards (after the namesake mechanic in Granblue Fantasy), are similar to Dreadnought Guards, except they cannot be directly healed by friendly units[note 3] but recovers HP in each attack to offset that and their talent buffs their ASPD as their HP lowers. Musha Guards also have the highest DP cost of all Guards.
Instructor Guards (Chinese: 教官; Pinyin: Jiàoguān), formerly known as Support Guards, have a range of two tiles ahead of them and their attack deals more damage against enemies they are not blocking, but their attacks are still considered as melee (thus they cannot attack aerial enemies). Instructor Guards are capable of providing support for other Operators with their talents which can be enhanced by their skills.
Liberator Guards (Chinese: 解放者; Pinyin: Jiěfàng zhě) are similar to Dreadnought Guards, but they will only attack and block enemies when their skill is active, and have their ATK gradually increase sometime after their skill is not active, reverting to normal when the skill expires. Liberator Guards have an unusual attack range of the tiles in their front and sides, can block two (three at Elite 2) enemies like Centurion Guards, and have 80s of redeployment time unlike the other subtypes.
Reaper Guards (Chinese: 收割者; Pinyin: Shōugē zhě) hit all enemies within their very unusual sweeping range of 1×3 tiles ahead of them, but cannot be directly healed by friendly units[note 3] and recovers HP for every enemy hit in each similarly to Musha Guards, up to their block count; Reaper Guards can only block a single enemy or two from Elite 1.
- Out of all eight Operator classes, the Guard class has the most members; with the introduction of class branches, the Guard class have the most branches as well. Because of this, the Arknights community jokingly calls the game "Guardknights".
- When blocking an enemy, Lord Guards will use a melee attack which deals full damage.
- "Warrior" in Japanese; written with the same kanji as the Chinese name (武者)
- Indirect healing, such as from Angelina's Part-Time Job talent, affects the Operator as usual.