One-hit knockout move

One-hit knockout moves (Japanese: 一撃必殺技(いちげきひっさつわざ) one-hit knockout move), commonly abbreviated as one-hit KO moves or OHKO moves, are moves that deal fixed damage to bring the target's HP to 0 and thus fainting, but have a particularly low chance to successfully hit the target.

One-hit knockout move

Fissure	Guillotine
Ground	Normal
Horn Drill	Sheer Cold
Normal	Ice

In the core series

	This move effect may be in need of research. Reason: 1. Can Endure, Focus Band, and Affection allow a Pokémon to survive a one-hit knockout move (in each generation)? 2. Interaction with substitute 3. Does the accuracy formula change against the Dynamax barrier? You can discuss this on the talk page.

One-hit KO moves deal fixed damage to bring the target to 0 HP (65535 in Generation I, equal to the target's current HP from Generation II onward). Despite being damaging moves, they do not consume a Gem. If the target faints, the game displays the message "It's a one-hit KO!" (or simply "One-hit KO!" in Generation I).

In Generations I and II, super effective one-hit knockout moves display the super effective message and play the appropriate sound effect. From Generation III onward, type-effectiveness messages no longer appear, but appropriate type-effectiveness sound effects still play.

In Generation III only, due to an oversight, a one-hit knockout move can fail to break a substitute. If a Pokémon's substitute has more HP left than the Pokémon does, the substitute will not break when hit by a one-hit knockout move. This occurs because one-hit knockout moves deal damage equal to the Pokémon's current HP. This oversight was fixed in Generation IV.

Pokémon with the Ability Sturdy are immune to one-hit KO moves. Since one-hit KO moves deal damage, a Focus Sash or the Ability Disguise can allow a Pokémon to survive such moves.

All OHKO moves have a base PP of 5. If an OHKO move becomes a Z-Move, it will have a base power of 180. If it becomes a Max Move, it will have a base power of 130.

One-hit KO moves will always fail against Dynamax Pokémon and Tera Raid bosses are unaffected by them. However, in Max Raid Battles, one-hit KO moves can deplete two bars of strength from a mysterious barrier.

OHKO moves are not featured in Pokémon Legends: Arceus.

Accuracy mechanics

Generation I

All OHKO moves have an accuracy of 76/256 (approximately 30%), but they will automatically fail if the user's Speed stat is lower than the target's. An X Accuracy will guarantee that all OHKO moves hit. The accuracy of OHKO moves in Generation I is affected by the standard accuracy and evasion stats.

Generation II

OHKO moves automatically fail if the target has a higher level than the user. Their accuracy starts at 76/256 (approximately 30%) and increases by 2/256 (approximately 0.8%) for each level the user is above the target. This means that if the user's level is at least 90 levels greater than the target's, the move will have 100% accuracy. An X Accuracy will guarantee that all OHKO moves hit. The accuracy of OHKO moves in Generation II is affected by the standard accuracy and evasion stats.

Generation III onward

OHKO moves automatically fail if the target has a higher level than the user. Their accuracy starts at 30% and increases by 1% for each level the user is above the target. Accuracy and evasion stats no longer influence the move's accuracy, including modifiers that do not use stages, such as Gravity, Wide Lens, and Compound Eyes. Effects that allow moves to always hit (such as No Guard or Lock-On, but not Telekinesis) still work on OHKO moves.

Since Generation VII, the accuracy of Sheer Cold starts at 20% instead if the user is not Ice-type. In addition, all OHKO moves now display their accuracy as 30% instead of —, although the calculation remains unchanged (except for Sheer Cold used by a non-Ice-type Pokémon).

In spin-off games

Pokémon Mystery Dungeon series

In the Pokémon Mystery Dungeon series of games, OHKO moves can hit regardless of level, although they are very prone to missing as always. When one hits, the game states that the target fainted through "calamitous damage" (changed to the standard "It's a one-hit KO!" in Gates to Infinity). However, they actually do 9999 damage, which can be seen when the attacks are reflected by IQ skills such as Counter Hitter if the Pokémon is revived by a Reviver Seed.

Trivia

• Lapras can learn the most one-hit KO moves of any Pokémon (excluding Smeargle), being able to learn Sheer Cold, Fissure, and Horn Drill.
• Starting in Generation VII, all one-hit KO moves are normally ineffective against one type. Fissure cannot affect Flying-type Pokémon, Guillotine and Horn Drill cannot affect Ghost-type Pokémon, and (starting in Generation VII) Sheer Cold cannot affect Ice-type Pokémon.
  • Immunity to Sheer Cold is the only one not based on a type immunity, and thus cannot be bypassed (e.g. with Gravity, Foresight, or a Ring Target). Sheer Cold is also the only one-hit KO move where this immunity did not exist until after its debut generation.
• Starting in Generation VII, Sheer Cold is the only one-hit KO move with different accuracy mechanics from other one-hit KO moves.
• Sheer Cold is the only one-hit knockout move to be introduced after Generation I.

In other languages

Language Title Chinese Cantonese 一擊必殺的招式 Yātgīkbītsaat-dīk Jīusīk Mandarin 一擊必殺的招式 / 一击必杀的招式 Yījíbìshā-de Zhāoshì / Yījībìshā-de Zhāoshì French Capacité pouvant mettre K.O. en un coup German K.O.-Attacke Italian Mossa che causano KO immediato Korean 일격필살 기술 Ilgyeokpilsal Gisul Spanish Movimiento fulminante

References

This article is part of Project Moves and Abilities, a Bulbapedia project that aims to write comprehensive articles on two related aspects of the Pokémon games.