«Extra Skills» (エクストラスキル, Ekusutora Sukiru?), also known as «Hidden Skills», are the kind of Weapon Skills in Sword Art Online with no clear conditions to unlock them, however, most of these skills have at least ten known users who are using them. Certain «Extra Skills» are limited to only one known user per skill and are therefore called «Unique Skills».

Although the exact condition or the quest required to unlock these skills are not publicly known, two known ways of unlocking «Extra Skills» have been revealed so far. Some of these skills are unlocked by training certain regular Weapon Skills, for example, the «Katana» skill appears quite often, as long as the «Curved Sword» skill is trained. Certain other skills are acquired as quest rewards, for example, «Meditation» is acquired by completing a certain quest on the 6th Floor. Like Weapon Skills, most «Extra Skills», including «Unique Skills», have their own special «Sword Skills».

It is said that ten or more Extra Skills have been discovered by the boss battle of the 74th Floor, but only five Extra Skills have been revealed in the novels so far.

Known Extra SkillsEdit

English Name Japanese Name Acquisition References
(Unique Skill)
Unlocked by completing the «Katana» skill.[1][citation needed] [2]
Darkness Blade
(Unique Skill)
(Ankoku Ken)
Unlocked by killing the most other players.[1][citation needed] [2]
Dual Blades
(Unique Skill)
Given to the player with the fastest reaction speed. [3]
Holy Sword
(Unique Skill)
Given to the strongest player. [citation needed]
Infinite Spear (Unique Skill) 無限槍
(Mugen Yari)
Unlocked by completing the «Two-Handed Assault Spear» skill.[1][citation needed] [2]
Katana (カタナ)
Unlocked by training the «One-Handed Curved Sword» skill. [5][6]
Martial Arts 体術
Unlocked by completing a quest to break a nearly unbreakable rock on the 2nd Floor.[† 1] [7]
Meditation 瞑想(めいそう)
Unlocked by completing a certain quest given by an NPC on the 6th Floor. [7]
(Unique Skill)
Unlocked by completing the «Blade Throwing» skill.[1][citation needed] [2]


  1. The skill is also present in ALfheim Online, but it is not clear whether it is an Extra Skill there or not



Skills and Magic
Default Sword Skills
mostly common in SAO, New ALO, UW
Avalanche - Cyclone - Deadly Sins - Embracer - Explode Arrow[1] - Fell Crescent - Flashing Penetrator - Horizontal - Horizontal Arc - Horizontal Square - Howling Octave[2] - Lightning Fall - Linear - Meteor Break - Meteor Fall - Rage Spike - Reaver - Savage Fulcrum - Senda - Sharp Nail - Single Shot - Slant - Snake Bite - Sonic Leap - Spinning Shield - Star Splash[2] - Starburst Stream[3] - Treble Scythe - Tsumujiguruma - Tsujikaze - Ukifune - Vertical - Vertical Arc - Vertical Square - Vorpal Strike - Whirlwind
SAO Dual Blades - Extra Skills - Fishing - Hiding - Holy Sword - Searching - Sewing - Tracking - Unique Skills
ALO Original Sword Skill(Mother's Rosario (OSS))
Magic Butterfly Shield - Cold resistance spell - Concealment - Earth Wall - Fireball - Fire Spear - Healing Magic - Hit Point Buff Magic - Hollow Body - Ice Arrows - Metamorphosis - Moonlight Mirror - Night Vision - Purified Surface - Retrieve Arrow - Sacrifice - Searcher - Smokescreen - Strength Buff Magic - Vacuum Blades - Water Breathing - Wind Needles
Project Alicization Sacred Arts - Incarnation - Synthesis Ritual
  1. Only in ALO.
  2. 2.0 2.1 Only in SAO and ALO
  3. Only in SAO
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