"Grass absorbs water. If you hit a bird with a brick, it'll stop moving. Afraid of the dark? Punch it."
— Professor Tree, So This Is Basically... Pokémon
The Pokémon franchise's complex type matchups rely heavily on exploiting logical weaknesses.
- Electric-type attacks are strong against Water-types because water conducts electricity while having no effect against Ground-types (think "grounding").
- Heavy rain will halve the power of fire, or conversely, intense sunlight will halve the power of water.
- Grass-types are typically weak to bugs since most bugs subsist on plants.
- Similarly, Bug-types are typically weak to Flying types thanks to the fact that many flying types, being birds (and several flying type moves are bird-based), are the natural predators of bugs.
- Why are Pokémon with the Water/Ground type combination doubly weak to Grass? Because most plants need water and soil (Ground) to live. Similarly, Rock-types have trouble with the eroding power of water, not to mention rocks sink in water.
- Fire-types are strong against Grass, Ice, Bug, and Steel-types. Fire kills plants and bugs and melts ice and steel.
- Dragon's weakness to Ice reflects most dragons being reptiles, which aren't usually capable of controlling their body temperature. Grass-types can't tolerate cold temperatures very well, either — after all, cold temperatures can kill off plants.
- Poison's weakness to Ground. Ever been in a chemistry lab (whether it's one in school or not) where kitty litter-like substances are used to absorb chemical spills? And it's useless against Steel (think stainless steel, a possible container for toxic chemicals, and the fact that poisons only affect organic matter, which steel is not).
- Fighting does half-damage to Flying-types, because, well, it's kind of hard to punch a bird
(and most birds are skilled at attacking their prey from above). It does no damage to Ghost-types, because ghosts are incorporeal. Then again, Ghost-types can't hurt Normals, either, since normal people don't believe in ghosts. So why can Ghost-Types hurt Fighting-Types? Well, this is a case of being Hoist by His Own Petard; the strict discipline of martial artists means they are more attuned to the world around them, including the spiritual. Also, just because you can feel the ghost doesn't mean you can hurt it. - Psychic is weak to Bug, Ghost, and Dark types, all common phobias. It's hard to concentrate when you're frightened.
- Fire-types are weak against Water-types because water puts out fire.
- Fairy's weaknesses reflect traditional weaknesses of The Fair Folk, such as Cold Iron (Steel) and certain incenses (Poison). There's also a bit of Green Aesop at work here, since Fairies are traditionally associated with life and nature, whereas Steel and Poison represent the industry and pollution that encroach on and destroy it. Fire also resists Fairy, since fire is a common ward against The Fair Folk in many cultures and tales.
- Ground does no damage to Flying, because it doesn't make sense to manipulate the ground while your enemy hovers in the air. Rock, however, is effective against Flying, since it involves launching the rocks at the flier, and basically has the same effect as shooting a bird with a rock via a slingshot.
- Ice and Rock are weak to Fighting. We've all seen those demonstrations where master martial artists use their hands, feet, and heads to break open blocks of ice and concrete, haven't we? Same with bending Steel.
- Grass is weak to Poison. Weed-killers and herbicides are made to get rid of plant life.
- Fighting is weak to Psychic, because of the old "brains over brawn" conflict. Also it's hard to hit someone when they're reading your mind and foreseeing your every move.
- Rock and Ice are weak to Steel, because metals, especially when refined into usable tools, are harder than stone and ice. Stone can also be made into tools and is harder than ice, which is why Ice is weak to Rock.
- Flying is weak to Electric and Ice, as lightning and icing conditions are hazards frequently faced by flying creatures and airplanes alike.
- Why is Psychic strong against Poison? Either because the brain controls the immune system and can get rid of most illnesses and diseases (the "poisons" of the body) or it's symbolic of how common sense and learning can prevent poisonings from happening.
- Dark's strengths and weaknesses make more sense when one considers that it's called the "Evil" type in Japan (even though dark types can still be good, so we get a weird case of Evil is Not Evil), and some aspects of Japanese culture in general. They're immune to psychic types either because Good Cannot Comprehend Evil or because A Mind Is a Terrible Thing to Read; they're advantaged against ghosts because the most threatening end for a ghost is demons (Houndooms?) coming to collect them; and they're weak against bug and fighting-types because insects and martial artists are "heroic" archetypes in Japanese pop culture (just look at Kamen Rider), and so the natural predators of dark-type "villains". Fairy types being effective against Dark types may be reminiscent of "holy" or "light" archetypes being the enemies of dark type villains in the western world.
- There are two types weak against themselves: Ghost and Dragon. Ghosts are often portrayed as being more of a threat to each other on the astral plane than to anything in the physical one, whereas in many myths and legends, the most and/or only effective way to kill a dragon or other large monster is with another dragon.
- Any Pokémon using Dig takes double damage from Earthquake and Magnitude. Makes sense given that being underground is generally one of the last places you want to be during an earthquake. Something similar goes on for using Surf on a Pokémon that has used Dive, as a sudden current will be worse for you if you're underwater.
- Why are Ice types strong against Ground? Same reason cities in temperate climates are often notorious for potholes. When water gets inside cracks in the street and freezes, it makes the crack expand.
- The reason why Gust, Twister, and Whirlwind ignore Fly, Bounce, or Sky Drop's invulnerability effect is that they are manipulating the air. That also explains why the former two deals double damage as being in the air is the last place you want to be when a tornado or a hurricane is ongoing.
- Any Pokémon in the rain or in the air are definitely going to be hit by Thundernote , as lightning strikes are common during rain storms and like the previous example, being high up in the air is a great way to be struck by lightning.
- On the opposite end, Thunder has its accuracy halved under harsh sunlight, as any lightning strike in clear weather would literally be a bolt out of the blue.
- Gravitynote has such effects because it's going to be very difficult to move about if the gravity is higher, which can also make attacks more likely to land as the opponent needs more time between reacting to the attack and actually getting out of the way. Also, having high gravity negates Levitatenote and the Flying-Type since trying to stay airborne is very difficult under high gravity. Generation 8 added another side effect — Flapple's Secret Art Grav Apple has more power as it involves, well, gravity.
- Minimizenote causes its user to take double damage from several moves such as Stomp, Body Slam, and Flying Press, all of which are based around slamming into the enemy from above. Shrinking your body would just make such impacts hurt more.
- Fighting-type attacks are strong against Normal-types, because a skilled martial artist can mop the floor with an untrained fighter.
