The mainline Pokémon games are one of the most accessible JRPG series to get into due to their relatively easy difficulty. Except for certain boss fights (Gym Leaders, Elite Four, etc.), the games are as easy or difficult as players want to make them -- depending on whether they choose to venture into competitive play.
That being said, though, there are several key mistakes most, if not all players are prone to make on their first Pokémon playthroughs. These slip-ups range from focusing too much on training their starter, forgetting the Type matchups, or leaning too hard into raw damage output.
Picking The Starter With The Early-Game Disadvantage
Picking one of the weaker starter Pokémon of the bunch without knowing the disadvantages ahead is one of the most commonly made mistakes. Depending on the generation, picking a certain Pokémon may immediately put players on the defensive with some early Gym Leaders, rival battles, and more that lie ahead.
The most infamous case for longtime fans is likely when choosing Chikorita from the second generation/Johto region. Despite the line's admittedly endearing design, this monotype Grass Pokémon makes it seem like the Johto region was designed against it. Those games started with a Flying-Type and Bug-Type Gym right from the off, which are direct counters to Grass.
Overtraining Their Starter Pokémon
In an opposite problem to beginning with a weak starter, picking some of the best starter Pokémon could lead to a dose of favoritism from players. Picking the likes of Venusaur, Blaziken, Greninja, and others could easily lead to payers overtraining them given their inherent strength.
It can happen even if players are still catching other species on the side, they just end up being relegated to the sidelines. This creates several issues, one of which being that once that starter meets an opponent with a clear advantage over it, there's no support to rely on.
Forgetting The Type Matchups
A staple of the mainline Pokémon series has been the classic rock-paper-scissors-style Type matchups between its various species. It's an overall straightforward chart to have memorized naturally throughout several playthroughs, but someone new to the series could easily be overwhelmed to start.
As easygoing as the Pokémon games generally are, a fun and smooth ride through a game could come to a frustrating stop if players don't realize what they're up against. For instance, Steel-type Pokémon are some of the strongest in the games, but a new player could be surprised to see them also get devastated by Fighting or Ground-types like Rock-types do.
Not Diversifying Their Teams
The biggest appeal to the Pokémon games is, of course, catching and raising hundreds of different species. However, in an issue that can go hand-in-hand with players prioritizing their starter over everyone else, not having a Type-diverse team of Pokémon can easily become a detriment.
Most of the trainers and Legendary Pokémon that players will encounter have creatures of different Type combinations, so having only one or two present within the players' team will eventually put them at a disadvantage. In addition to having several different Types available, players should experiment with the various Pokémon that have a Dual-typing.
Neglecting Held Items
On top of a Pokémon's Type and moves, Held Items are another mechanic that can be used to gain an edge in battle. While they aren't particularly necessary to win battles in the story, they can provide a key boon in one of the tougher boss fights.
These items can range from things like Charcoal (which boosts Fire-type attacks) to berries that trigger automatically in a battle to heal, and more. Generation 2 onwards used Held Items as a mechanic, so it couldn't hurt to read the descriptions of those seemingly random items found during players' Pokémon journeys. And when it comes to competitive battling, these are essentially a requirement.
Neglecting HP Healing Items
It's understandable given these games' aforementioned friendly level of difficulty that players can start to feel comfortable brute-forcing their way through the story. At times, this includes skipping stocking up on medical items.
But even for the most confident players, it's also common to come into a pinch during a battle and realize they never bothered to stop by the mart to buy potions. Berries can factor in this too, especially since some are free to pick in the wild, but making sure players are carrying plenty of Potions, Super Potions, Hyper Potions, and more are crucial nonetheless.
Neglecting Status-Curing Items
Potions are one thing, however, given the kinds of Pokémon that players can meet in battle, stocking up on status-curing items can be just as important. Even in simple story playthroughs, having a teammate afflicted with Poison, Burn, Paralysis, and more can ruin players' otherwise steady progress through the games.
Especially if players find themselves dealing with a status ailment in the middle of a dungeon. Having fainted Pokémon also counts toward this, making Revives and/or Max Revives another necessity while adventuring and during Gym Leader/Elite Four challenges.
Unprepared For Competitive Training & Battling
When it comes to difficulty, there's a notable spike when transitioning from single-player gameplay to competitive battling. The metagame has an admittedly high barrier to entry, though it's gotten steadily lower and more streamlined since the 7th generation.
Needless to say, newcomers to the competitive scene are often met with a rude awakening. Competitive battling involves far more grinding, namely when it comes to breeding for certain Natures, IVs, EV training, Pokémon movesets, and overall team synergy to be best prepared for what an online opponent might throw out.
Focusing Too Much On Damage Vs. Strategic Moves
Battling with Pokémon more strategically is another requirement if players want to consistently win online battles, but experimenting with different moves can be worthwhile regardless of the format. Especially for longtime fans, many will remember the days when the answer to challenges was simply to spam attacks like Earthquake as many times as possible.
However, using more defensive and status-affecting moves will pay off in the long run. There are countless powerful stat-boosting moves in Pokémon, so being able to get one Swords Dance in to raise a Pokémon's Attack or a Thunder Wave to Paralyze a foe might be the difference between victory and defeat.
Knocking Out A Shiny Pokémon
Though coming across a coveted Shiny Pokémon is rare enough as it is, there have been hundreds of stories told by players online of the times they accidentally KO'd one. The odds of encountering a Shiny have been lowered over the years, namely with Key Items like the Shiny Charm.
But even with items and clever exploits, accidentally knocking out a wild Shiny is one of the most gut-wrenching mistakes a player can make. There's nothing statistically beneficial to catching a Shiny variation, but even though it's purely an aesthetic feature, it's made these Pokémon all the more desired since the mechanic's introduction in Gold and Silver.