Unblockable

Ares breaking block with God Smack.

An Unblockable attack cannot be blocked. They will deal the same damage and apply the same effects regardless of block. All super moves are unblockable, but can be resisted for up to 50% of their damage in Online Battles.

Mechanisms

There is a subtle difference between an unblockable attack and a block breaking attack (also called block breaker). The former has a wider definition; it includes unblockable moves used against an opponent who wasn't blocking in the first place. Block breaker is the hit that breaks block; therefore, if the enemy is not blocking, there will be no block breaker. This is significant because a block breaker cannot crit (this is easily seen on Deathstroke/Arkham Origins's infamous special 1, the first hit cannot crit if it breaks block). However, it can still apply other gear effects, such as power drain, and can be affected by reflect special. Additionally, while Static's passive does not work against a block breaking special, Superman/Godfall's passive does work against a block breaking basic attack.

Previously, inherent unblockable attacks are penalized by having their damage reduced by 50%. While the likes of Ares/Prime's God Smack are unblockable, they are technically a part of their passives and will be disabled in Dead Zone. Killer Frost/Prime's Black Ice is the first special to be at least partially unblockable without penalty and with no association to passives.

Block breaking attacks can still be reflected by gear or passives such as Static's Charged Disc and Superman/Godfall's passive, but only the first hit that breaks block, not the following ones that cannot be blocked because you are already being hit.

Superman/Blackest Night's passive grants immunity to block breaker to all Blackest Night characters. His passive doesn't work against Super Move and block breaking effects that don't deal damage: The Flash/Earth 2's tag-in stun and Deadshot/Suicide Squad's block disable.

Unblockable attacks

• Batman/Blackest Night grants him and all fellow Blackest Night characters an unblockable chance on all attacks.
• Batgirl/Cassandra Cain has an unblockable tag-in attack.
• Catwoman/Batman Ninja has an unblockable tag-in attack.
• Deathstroke/Arkham Origins's Point Blank is unblockable if 200% is reached.
• Doomsday, Martian Manhunter, Nightwing, Solomon Grundy and The Flash have access to a percentage chance of unblockable basic attacks with their signature gear; The Arkham Knight's Custom Rifle and Killer Croc's Massive Sharpened Teeth both offer a chance of unblockable basic attacks to any character, but the chance is lower to compensate.
• The Flash/Metahuman's basic attacks have a chance to be unblockable and crit during his passive.
• Superman/Regime's Heat Vision.
• All versions of Harley Quinn have an unblockable bomb as one of the three possible items from her Bag-o-Tricks (four in the case of Harley Quinn/Suicide Squad).
• Doomsday/Regime's next special is unblockable upon knocking out an enemy.
• Bane/Luchador's chance to stun upon tag in.
• Harley Quinn/Arkham gives all Arkham characters a 50% unblockable chance on every hit of their special 2.
• Ares/Prime's God Smack. His passive also allows him to disable entire enemy team's ability to block after his SP2 (if it doesn't knock out its opponent).
• Killer Frost/Prime's Black Ice is partially unblockable; only the third hit of the starting frozen wind is unblockable.
• Superman/Godfall's Frozen Delivery is partially unblockable; only the third hit, the freezing breath is unblockable.
• Batman/Red Son gives all Red Son characters an unblockable chance on their special 1.
• Deadshot/Suicide Squad has a chance to disable block when a Suicide Squad teammate uses a special.
• The Flash/Earth 2's tag in stun cannot be blocked, although not a normal block breaking attack as it doesn't deal damage and ignores Invulnerability.
• Achieving 190%+ on Nightwing/Batman Ninja's SP1, Warrior of the Night, will cause it to become unblockable, although it's not explicitly stated in his Passive or Special’s description.
• Upon landing 12 basic attack hits (minimum 7 when evolved) without getting openly hit himself, The Merciless/Metal's next special cannot be blocked.

Gears that grant unblockable basic attack chance are:

• Custom Rifle (The Arkham Knight)
• Hyperspeed Plated Suit (The Flash)
• Knife Collection (Solomon Grundy)
• Martian Hunter Garb (Martian Manhunter)
• Massive Sharpened Teeth (Killer Croc)
• Mutated Bone Spikes (Doomsday)
• Powered Eskrima Sticks (Nightwing)
• Soultaker Sword

Testing indicates unblockable chance on basic attacks stack multiplicatively. Even if The Flash/Blackest Night has Soultaker Sword, Hyperspeed Plated Suit, and Massive Sharpened Teeth, and is teamed with Batman/Blackest Night and another Blackest Night teammate, his basic attacks still won't have 100% unblockable chance (but rather, maximum of 70.6%, in theory).

There are a few effects that, while not technically block breaking, forces you to stop blocking briefly:

• If The Batman Who Laughs gets the chance to pick a card after using a special, the opponent's block is disabled until the card hits.
• When Batgirl/Arkham Knight rescues a teammate (triggered if the teammate would otherwise be KO'ed, which can be done while blocking with deflect damage), her opponent's block is disabled before she throws a stunning smoke bomb.
• The Flash/Elseworld's passive disables block (along with special attacks) when triggered by reflect damage (does not disable when triggered by Raven/Prime's passive).
• Ares in Breakthrough will disable block when he activates RAGE (or is about to, which may allow him to use his specials without being able to block). Characters will automatically block if RAGE is successfully defended.
• Batman/Gaslight prevents the opponent from blocking when he is evading an enemy tag in and throws a grenade due to his passive.

There are some specials that are not meant to be unblockable, but are glitched to occasionally cause you to randomly stop blocking (the text "block breaker" does not pop up for these).

• Aquaman/Flashpoint's Cephalopod Strike (particularly on the 3rd hit)
• Batman's Explosive Batarang (versions with 7 hits)
• Darkseid's Omega Blast
• Lex Luthor's Lance Blast
• Harley Quinn/Animated's Hammer Slam
• Catwoman/Batman Returns's Scaredy Cat
• The Arkham Knight's Tortured Soul
• Batman/Beyond Animated's Future Bat
• Green Lantern/Red Son's Guardian
• Green Lantern/Jessica Cruz Rebirth's Getting The Hang Of This
• Solomon Grundy/Earth 2's Can't Stop Grundy

Trivia

• During the 2.10 update, a bug prevented all unblockable attacks from working. Block breaking specials did not work, despite that full damage is still dealt. When such an attack was blocked, any attack used against the block-breaker user themselves would become a block breaker; but the damage was still halved for this kind of glitched block breaker. Partially block breaking specials (Superman/Godfall and Killer Frost/Prime's s2s) could not break block either, but they did not function as unblockable hits. Specials with a chance to break block on each hit (from Harley Quinn/Arkham's passive) functioned like a normal block-breaking attack. This issue was resolved in the 2.10.1 update.