‘Complex beast’: Official Pokémon legality check continues to crumble in the face of data

The Pokémon Company International (TPCi) has been increasingly strict about hack checks at in-person tournaments, but more and more evidence is pointing to flaws in the system—and it could even be penalizing the wrong players.

Kurt a.k.a. “Kaphotics,” creator of the genning program PKHeX, posted a report on X (formerly Twitter) on May 6, mainly regarding a “new instance of VGC judges incorrectly removing a Pokémon” from a player’s team. According to Kurt, the issue revolves around traded eggs and can be triggered if the breeder has “a very long OT name.”

The PKHeX creator stated if you have a long OT name, breed an egg, and trade that egg over to a player with a shorter name (by two characters or more), the Pokémon they hatch will likely fail TPCi’s hack check. Based on the rules, there’s nothing illegal about this, but it will still flag Pokémon hatched under these circumstances as hacked. After explaining all the science behind it, Kurt commented, “Legality checking is an incredibly complex beast filled with game quirks and edge cases across dozens of games.”

In fact, this wasn’t even the first instance of Pokémon hack checks gone wrong. Back in March, there was also an issue with Gold Bottle Caps causing perfectly legal Pokémon to fail hack checks. Gold Bottle Caps and Hyper Training may allow you to take some shortcuts when building your team for tournaments, but it’s a feature of the game and totally legal. Under no circumstances should a competitor be punished or disqualified due to a flaw in the hack check system when they didn’t break any rules.

Unfortunately, these types of errors can affect a lot of different players. Chances are, if players have Gold Bottle Caps in their bag, they’re eventually going to use them to give their Pokémon perfect IVs. Similarly, it’s totally normal to trade eggs to a friend—breeding and hatching eggs is part of piecing together a competitive team, and sometimes you might want help from a friend. It’s sad to think that trading with a friend or using a Gold Bottle Cap could get you in trouble at a tournament and paint you as a hacker without knowing.

But this just goes to show that hack checks need to be more reliable and accurate at future Pokémon events. It is nice that TPCi wants to reinforce the rules, but hopefully, the system can be fixed soon to keep the game fun and fair.