Generally, lots of things that the Pokédex in
Pokémon says directly contradict gameplay. Ironically, some examples were done correctly. One example is the Shedinja actually "shedding" from a Nincada, others could include a Mantyke requiring a Remoraid to evolve. If they were all Hand Waved, one could just assume they kept the games simple... but when half of it is correct, it turns weird.
- Drowzee/Hypno are said to live off of dreams; it's their defining trait. Yet they can only learn the attack Dream Eater by TM (or, in later games, via breeding). You'd think they'd be able to learn it by leveling up, but...
- Abra is said to sleep through most of the day, teleporting away from danger in its sleep, yet the Sleep status affects it just like everything else.
- Cubone is said to lose its mother as it is born and wears its skull as a memento. Breeding for a Cubone, however, doesn't cause any ill effects for the mother, whether or not it is a Marowak.
- Evolving Nincada into Ninjask also earns you a Shedinja, but only if you have a slot free in your party and an unused Poké Ball in your bag. For some reason you can't just ship the thing off to your PC like everything else you catch. And staring into Shedinja's backhole is supposed to mesmerize and then steal the soul of the victim. All of its player-side battle sprites have the backhole clearly visible, but nothing unusual happens to you when you fight others with it.
- Pichu is said to hurt itself whenever it uses a lightning based attack; however, this doesn't happen in the games unless you use Volt Tackle. Unfortunately, it does happen in Super Smash Bros. Melee, and is a significant drawback to using Pichu.
- The games insist on judging your power by number of badges, regardless of the level of your Pokémon. Mt. Silver should be no problem for a trainer with six Pokémon of levels 80-100, but you can't get to it unless you have 16 badges. Of course, the same argument could be made at that point that getting those badges should be rather easy.
- Supposedly, Charizard's fire breath is hot enough to melt boulders. Still doesn't have much effect on Rock types. It's also stated that the surface of Magcargo's skin is hotter than the surface of the sun. Somehow, the Earth and everything else around it aren't becoming instant slag. Spiritomb is 108 souls sealed in a stone, but it can breed and create more Spiritomb. Arcanine is renowned for its impossible speed, but there are a lot of mons that have higher Speed stats, including its counterpart, Ninetales.
- Metapod and Kakuna are supposed to be totally immobile and only know Harden. And ones you fight in the wild do only know Harden. Where this trope comes into play is that a Caterpie or Weedle you evolve yourself will still know the moves it did before. Pupitar, on the other hand, are flat out stated to be fully mobile.
- Regice is stated to be so cold that dipping it in magma would not harm it at all and instead freeze the magma solid. Just being near it exposes you to the intense aura of near-absolute zero air surrounding it. Yet its opponents suffer no ill effects from biting it, punching it, kicking it, wrapping their bodies around it, etc. And fire is still super-effective against it.
- In Generation I, only Pokémon with the bird-like overworld sprite could learn Fly. This meant that you couldn't fly on the back of a Charizard (in Red and Blue), Golbat, or Dragonite, but a tiny Pidgey had no problem ferrying you from one side of the region to the other. Venomoth and Beedrill can clearly fly but are not classified as flying types. Doduo and Dodrio are said to have poor flying skills and have no visible wings, nevertheless, they can learn Fly. This one at least has a explanation; the Japanese name for the move can also mean "Sky Jump."
- Qwilfish is often refered to as a bad swimmer, but can learn Surf and has Swift Swim as one of its abilities.
- The Pokédex entry for Escavalier says it flies around at high speed. Turns out it is one of the slowest Pokémon in the game.
- Many Pokédex entries for the Slowpoke line make mention of Shellder biting onto a Slowpoke's tail/head in order to evolve. While it is like this in the anime, one does not even need to see a Shellder to evolve Slowpoke into Slowbro (evolves via leveling up) or Slowking (evolves via trade while holding a King's Rock) in the games.
- Nidorina and Nidoqueen are unable to breed, perhaps originally due to a bug in Gold and Silver, four major engine rewrites and fifteen years ago. This is despite the fact that their Pokédex entries mention (and in the case of the latter, make a major point out of) them taking care of their young.
- Snorlax cannot be battled at all without waking it first with a pokeflute, but once the battle begins you're free to both fight it when it uses Rest (making itself fall asleep) and put it to sleep yourself. Likewise you can't use any sleep canceling attacks or abilities to wake it without the flute.
- Goomy's Pokédex entry describes it as the weakest of all Dragon-types, even though stat-wise, that designation belongs to Noibat.
- Anytime an NPC stands in your way and bonus points if they're an enemy team grunt. The point of a pokemon battle is that a regular human can't fight even low level pokemon without risking serious injury so wining a battle means that the opponent has no defenses and likely has to flee. If a grunt flat out refuses to stop blocking your path they're treated like an impenetrable wall rather than someone you could use your endless array of abilities on even if you wanted to be gentle and just use a sleep attack.
- This same problem applies to the existence of HMs. These moves are the only things that can solve puzzles outside of battles, doing things like destroying rocks, moving boulders, or cutting down trees. Things like swimming or flying are more or less sensible, but the game never really explains why a tiny little bush can only be cut down by a special hidden technique, and not, say, any of the dozens of moves that should be effective at getting a tiny little bush out of the way. This might make sense if Cut was a strong move and could therefore destroy obstacles that Fury Cutter or Slash or Sacred Sword or Flamethrower can't, but in battle, Cut is utterly unremarkable even for an early-game move.
- Mega Evolution is supposed to be possible because of strong bonds between trainer and Pokemon. However, Mega Evolution has no required Friendship level, and in fact the first time you press the button is with a Lucario you just received, with 70 Friendship.