Poison-type Pokémon are weak to just two types: Ground and Psychic. Moves of either type deal double damage to a pure Poison type in the main series games, and 1.6x damage in Pokémon GO. Poison resists five types (Fighting, Poison, Grass, Bug and Fairy) and has no immunities, though a second type can change all of that.
So if you’re staring down a Muk, a Toxapex or a Nidoking, reach for Earthquake or a Psychic move first. The catch is dual types, and almost every Poison Pokémon has one.
Poison type weaknesses and resistances at a glance
Here is the full defensive picture for a single-type Poison Pokémon, as listed on Bulbapedia and PokémonDB for the current games (Generation VI onward).
| Attacking type | Damage to a Poison type | Pokémon GO equivalent |
|---|---|---|
| Ground, Psychic | 2x (super effective) | 1.6x |
| Fighting, Poison, Grass, Bug, Fairy | 0.5x (not very effective) | 0.625x |
| Everything else | 1x (normal) | 1x |
That resistance list is long for a type with only two weaknesses, which is why Poison is a useful defensive type. Fighting and Fairy moves, which flatten plenty of other types, both bounce off it.
Questions trainers keep asking about Poison matchups
“Why is Toxapex weak to Ground? Isn’t it mostly Water?”
A question on PokéBase came from exactly this confusion. The answers there were clear: there’s no “main” type. Every type a Pokémon has counts fully. Toxapex is Poison/Water, Poison is weak to Ground, and Water doesn’t resist Ground, so the double damage stays. Type order on the Pokédex page means nothing for damage.
“If my target is poisoned, do Psychic moves hit harder?”
No. In a PokéBase thread on this, the replies agreed that being poisoned is a status condition, not an extra type, so it never adds a weakness. One answer pointed to the one move that does care: Venoshock, which doubles its power against a poisoned target. That’s a move effect, though, not a super effective hit.
“Why does Psychic beat Poison anyway?”
The games never explain it. In a long Smogon question-and-answer thread, fans traded theories: a strong mind resisting illness, psychic power standing in for medical knowledge in Generation I, or telekinesis bursting the toxin sacs some Poison types carry. None is official. It’s a design choice from the original games that stuck.
“My Ivysaur took super effective damage from Dig in the old games. Wasn’t Grass supposed to resist Ground?”
Someone asked this on PokéBase about Generation I. The answer: the damage was actually neutral (Poison’s weakness and Grass’s resistance cancel out), but the game printed the wrong message. That display bug is a known Gen I glitch, and it explains why a lot of players grew up thinking Grass/Poison types were weak to Ground. They aren’t.
What is Poison weak to when it has a second type?
Multiply the two matchups together. A move that’s super effective against both types does 4x, one that’s super effective against one and resisted by the other does 1x, and an immunity on either type wins outright. Bulbapedia’s type page explains the rule. Applied to the most common Poison pairings, using the standard type chart, it gives this:
| Typing | Examples | Weak to | What changes |
|---|---|---|---|
| Grass/Poison | Bulbasaur, Venusaur | Fire, Ice, Flying, Psychic | Ground is only neutral |
| Poison/Ground | Nidoking, Nidoqueen, Clodsire | Ground, Water, Ice, Psychic | Immune to Electric |
| Poison/Flying | Zubat, Golbat, Crobat | Electric, Ice, Psychic, Rock | Immune to Ground |
| Poison/Dark | Skuntank, Drapion, Overqwil | Ground only | Immune to Psychic |
| Poison/Water | Tentacruel, Toxapex | Electric, Ground, Psychic | Few weaknesses, lots of resistances |
| Poison/Ghost | Gastly, Haunter, Gengar | Ground, Psychic, Ghost, Dark | Immune to Normal and Fighting |
| Poison/Bug | Beedrill, Venomoth | Fire, Flying, Psychic, Rock | Ground is only neutral |
| Poison/Psychic | Galarian Slowbro, Munkidori | Ground, Ghost, Dark | Psychic is only neutral |
| Poison/Fighting | Croagunk, Toxicroak, Sneasler | Psychic (4x), Ground, Flying | Psychic hits very hard |
| Poison/Fire | Salandit, Salazzle | Ground (4x), Psychic, Water, Rock | Ground hits very hard |
| Electric/Poison | Toxel, Toxtricity | Ground (4x), Psychic | Only two weaknesses, one doubled |
| Steel/Poison | Varoom, Revavroom | Ground (4x), Fire | Immune to Poison; Psychic is neutral |
| Poison/Fairy | Galarian Weezing, Fezandipiti | Ground, Psychic, Steel | Immune to Dragon |
| Poison/Dragon | Dragalge, Naganadel | Ground, Psychic, Ice, Dragon | Fairy is only neutral |
Two things jump out. Ground is the more reliable answer, since only Flying, Grass and Bug partners take the sting out of it, and Abilities such as Levitate can switch it off entirely. Psychic is the riskier pick: it does nothing at all to Poison/Dark Pokémon and only neutral damage to Steel and Psychic pairings.
Pokémon GO: poison weakness works the same, with smaller numbers
The matchups are identical in Pokémon GO. Ground and Psychic are still the types to use. What differs is the size of the multipliers, according to PokémonDB’s GO type chart:
- Super effective: 1.6x (2.56x if both of the target’s types are weak)
- Not very effective: 0.625x
- “Immune” matchups: GO has no true immunities, so they become a double resistance of about 0.39x
That last point matters for raids and the GO Battle League. A Psychic attack against a Poison/Dark Pokémon such as Skuntank or Drapion isn’t wasted in GO the way it is in Scarlet and Violet: the 1.6x and the 0.39x cancel out to roughly 0.63x. Still poor, but not zero. A Ground attacker remains the safer choice for almost every Poison raid boss.
What Poison moves are good against (and where they fail)
On the attacking side, Poison moves are super effective only against Grass and Fairy. They’re not very effective against Poison, Ground, Rock and Ghost, and they don’t affect Steel types at all (0.39x in GO). PokémonDB calls Poison “one of the weakest offensively”, and the numbers back that up: four resisting types plus a full immunity is a lot to work around.
Poison still earns a team slot because of Fairy. Since Fairy arrived in Generation VI, a Sludge Bomb is one of the cleanest ways to hit Fairy types hard.
Other Poison type perks worth knowing
- They can’t be poisoned. Poison types are immune to the poison and badly poisoned status, with one exception: a Pokémon with the Ability Corrosion (added in Generation VII) can poison them, per Bulbapedia.
- They clear Toxic Spikes. A grounded Poison type that switches in removes Toxic Spikes from its own side of the field.
- Toxic never misses for them. From Generation VI on, Toxic used by a Poison type skips the accuracy check, even hitting targets in the middle of Fly or Dig.
Did Poison always have these weaknesses?
Not quite. In Generation I (Red, Blue and Yellow), Poison types were also weak to Bug, and Poison moves were super effective against Bug types. Generation II flipped Bug into a type that Poison resists and added Steel, which Poison can’t touch. Generation VI then added Fairy, giving Poison both a new target and a new resistance. If you’re replaying a Gen I game, add Bug to the weakness list.
Frequently asked questions
What is Poison weak to in Pokémon?
Poison is weak to Ground and Psychic. Both deal 2x damage to a single-type Poison Pokémon in the main series games and 1.6x in Pokémon GO.
Is Poison weak to Fairy?
No. Poison resists Fairy, taking half damage from Fairy moves, and Poison moves are super effective against Fairy types.
Is Poison weak to Bug?
Only in Generation I. From Pokémon Gold and Silver onward, Poison resists Bug moves.
What type is Poison immune to?
None. A pure Poison type has no type immunities, but it can’t be given the poison status except by a Pokémon with Corrosion. Second types such as Dark, Flying or Ground add immunities to Psychic, Ground or Electric.
Why can’t Poison moves hit Steel types?
Steel is immune to Poison-type damage in the main series, so moves like Sludge Bomb do nothing. In Pokémon GO the same matchup deals about 0.39x instead of zero.
What is the best type to use against Poison Pokémon?
Ground is the most dependable choice. Psychic also hits Poison types for super effective damage, but Poison/Dark Pokémon are immune to it and Steel/Poison Pokémon take only neutral damage.
Sources
- Bulbapedia: Poison (type)
- Bulbapedia: Type
- PokémonDB: Poison type Pokémon
- PokémonDB: Pokémon GO type chart
- PokéBase: Why is Toxapex weak to Ground types?
- PokéBase: Does a poisoned Pokémon take more damage from Psychic moves?
- Smogon Forums: Orange Islands SQSA thread
Featured image: Nintendo / The Pokémon Company
