Can you put together any reasoning for why Pokémon can learn only four moves? I mean, I can understand from game perspective but from in-universe perspective? I suppose complicated magical moves would make sense but some moves like Tackle or Peck are really just simple basic body movements. How does learning how to breathe fire or squirt water make you forget how to ram your face into stuff?
Obviously there are compelling gameplay reasons for it, and early seasons of the anime (which doesn’t need to care about that) actually do play fast and loose with this rule occasionally – Drake’s Dragonite uses no fewer than ten different attacks in Ash’s Orange League championship battle. But cases like that are the exception, not the rule, and often seem meant to illustrate that a particular Pokémon is unusually powerful and skilled – most Pokémon can’t do it. Why? I think we need to compare how athletic skills and martial arts techniques work in the real world (because that’s basically what Pokémon attacks are). Video games have sort of conditioned us to expect that you learn an ability and then just have it; it never goes away and you can call on it any time. But that’s not realistic – in real life, you eventually lose martial and athletic abilities if you don’t practise them. You can’t just practise a move in isolation either; you have to use it in realistic contexts, in practise games or sparring matches, so that when you need the move for real, you won’t be thrown even slightly by the fact that the angle is a bit weird, or the ground is an unfamiliar texture, or there’s a strong wind blowing in your face. Pokémon have to be able to deploy their techniques more or less perfectly in a wide range of weather conditions and terrain types (up to and including no terrain at all), against an utterly bewildering array of potential opponents, each with unique combat forms and movement patterns. Some moves would, in the real world, count as whole martial arts styles on their own, when you consider how many different ways you can use them and in how many situations you might need to. Tackle may be the simplest move imaginable, but if you’re an ordinary Bidoof who learned Tackle on a grassy flat outside Sandgem Town in battles against other Bidoof or the occasional Shinx, and suddenly your trainer expects you to Tackle Cyrus’ Gyarados as it flies around the broken ground and alien kelp of the Distortion World while Giratina plays merry hell with the laws of gravity in the background, without falling straight into your opponent’s gaping maw and with a 95% success rate, all I can tell you is you’d bloody well better have practised that Tackle. Ordinary Pokémon may just not be able to maintain a proper training regimen that covers five or more moves to the kind of standard that we, the players, expect of them.