Instant KO

This article is about KOs that occur instantly with no launching or crossing of blast lines. For launching attacks powerful enough to KO in one hit, see One-hit KO.

Two fighters are thrown into a Danger Zone and instantly KO'd.

An instant KO is a type of KO which occurs instantaneously and in-place, without the fighter passing a blast line or being launched at all. A character suffering an instant KO will disappear into a colorful starburst explosion, then respawn as normal (or not respawn, if no stocks remain). Instant KOs were introduced as stage hazards in Super Smash Bros. Brawl, and a greater variety of attacks and conditions causing instant KOs were added in Super Smash Bros. 4 and Super Smash Bros. Ultimate. Ultimate also introduced instant variations of Star and Screen KOs.

Types of instant KO

Stage hazards

Crush: If a fighter is caught between two moving solid platforms, they are instantly KO'd when the platforms collide.
Danger Zone: Appearing as glowing pools or spiky objects, these hazardous obstacles can instantly KO fighters who touch them. Some Danger Zones only cause an instant KO if the fighter has accumulated 100% or more damage; otherwise, this variant merely damages and launches the fighter similarly to lava.

Final Smashes

Some fighters have Final Smashes that can cause instant KOs, usually when the opponent has reached a certain damage threshold.

Enemies and items

Certain enemies in various modes are capable of delivering instant KOs, sometimes with an attack, sometimes on contact. Starting in Ultimate, some Poké Ball Pokémon have instant KO attacks, and some items can cause instant KOs.

In Super Smash Bros. Brawl

Stage hazards

On the Pirate Ship stage, fighters can be crushed between the hull of the ship and the rock when the ship crashes into it.
Several levels in The Subspace Emissary feature objects that can crush the player: moving walls, blocks, elevators, and more.

All instant KOs in Brawl are the result of a crush.

In Super Smash Bros. 4

Stage hazards

After Midgar is cleaved apart by Odin, the two halves of stage will eventually reconnect. Any fighter caught in the middle when this happens will be crushed.
When Midgar is flooded by Leviathan, opponents with 100% or more damage will be instantly KO'd if the current sweeps them into the right side of the stage.
The Great Cave Offensive features numerous lava-like Danger Zones which instantly KO any fighter who touches them with 100% or more damage.
In Super Smash Bros. for Nintendo 3DS, two distinct types of Danger Zones appear in Smash Run:
- Some floors briefly become lava-like Danger Zones every few seconds, KOing fighters. These can be found in one area on the main map as well as some challenge rooms.
- Danger Zones in the form of lava-colored spiky orbs, which will instantly KO fighters regardless of accumulated damage, are dotted throughout the main map and also appear in some challenge rooms. The "Run!" and "Climb!" final battles also feature the spiky orbs, in addition to static pools which similarly KO regardless of damage.
In Super Smash Bros. for Wii U, the interior of Master Fortress is lined with acid-like Danger Zones which cause an instant KO at or above 100% damage.

Although Pirate Ship is a returning stage in for Wii U, the crushing hazard was removed. Players caught between the rock and the ship's hull will instead be launched and ricochet off the rock.

Final Smashes

At the end of Bayonetta's Infernal Climax, which can trap and damage multiple opponents, any opponent with 100% or more damage will be instantly KO'd.

Enemies and items

Orne, an enemy found in Smash Run in for 3DS, instantly KOs fighters on contact with its Obliviate effect.

In Super Smash Bros. Ultimate

Stage hazards

Returning stage Midgar features the same crushing and flood hazards it had in SSB4.
Returning stage The Great Cave Offensive features the same Danger Zones it had in for Wii U.
New Pork City is a returning stage with a new hazard: the bite of the Ultimate Chimera now instantly KOs fighters, instead of imparting extreme knockback as it did in Brawl.
The Red Bulborb on returning stage Distant Planet instantly KOs fighters with its bite, instead of carrying them off screen as in previous games.

Final Smashes

Bayonetta's Infernal Climax behaves as it did in SSB4.
Bowser's Giga Bowser Punch can instantly KO fighters with 60% or more after being punched (80% when using the weaker version via FS Meter).
Ridley's Plasma Scream can instantly KO fighters with 100% or more damage at the end of its animation.
Zelda's Triforce of Wisdom can instantly KO fighters with 100% or more or more damage at the end of its animation.

Enemies and items

Poké Ball summon Mimikyu will instantly KO the fighter it grabs hold of if they reach 90% damage after its attack.
Death's Scythe will instantly KO when striking a fighter at or above 80% damage with the tip of the scythe during a smash attack.

Other

Ultimate is the first game in the series where Stamina Mode can be played with multiple stocks. Under these conditions, fighters who lose all HP will suffer an instant KO and respawn as long as they are not out of stocks. When the last stock is lost, the standard Stamina Mode KO occurs with the fighter falling to the ground and lying there motionless, then exploding and disappearing for good after a short pause.
If an Inkling suffers an Instant KO, they do not have a standard explosion animation. Instead, as in the Splatoon games, they burst into a puddle of ink and their spirit, in the form of a squid, flies upward briefly before disappearing.