Pokémon Sword and Shield contains a new appearance effect for certain Shiny Pokémon, fans have discovered.
This phenomenon has lead some fans to dub the discovery as a new, even rarer tier of alternate-coloured monsters. But this may not be entirely true.
Shiny Pokémon are meant to be extremely rare in mainline Pokémon games. The odds of finding one are usually around 1/4000, and they offer no advantage other than having an alternate colour scheme. (Pokémon Go makes them considerably easier to find.)
But for collectors, the pursuit of Shiny Pokémon has long been an obsession. Pokéfans have spent hours restarting their games over and over until they get a Shiny version of their starter Pokémon, or employing one of the series' various mechanics to raise their chances of finding a Shiny by a fraction of a degree.
When one does arrive - its alternate colour scheme visible, and with an effect like a flash of stars to make sure you notice - it is a big deal.
So it's an even bigger deal that Pokémon Sword and Shield has certain Shiny Pokémon which boast an alternate effect. Instead of a flash of stars, they arrive with what looks like a flash of squares, or diamonds.
This comparison image comes from Reddit:
Today, we're starting to get an idea of why this happens. Peering into each games' code, Pokémon trainer Kurt claims to have found evidence that the likelihood of a Shiny with the square effect is 1/16th that of the base Shiny rarity.
This is determined, as ever, by each game profile's unique Trainer ID code, and whether it matches the number string of the unique Pokémon ID code in question. A shiny with the square effect requires an even "cleaner" match of these numbers, Kurt says.
In a surprising twist, it looks like chained shinies that are destined to be shiny are forced to be shiny in such a way that the xor results in 0 (squares). So, under certain conditions, you're more likely to get one than the other! pic.twitter.com/ZkjjivEwop— Kurt (@Kaphotics) November 20, 2019
But there's something else going on, too. A follow-up tweet suggests getting a Shiny Pokémon using chaining (a recently-added method which increases Shiny chances) actually pushes the chances of getting the supposedly rarer square effect much higher - making it unclear how much rarer it actually is. Kurt has said more research is now needed.
What is clear is that there are now two appearance effects for Shiny Pokémon in Sword and Shield. And for trainers who do want to catch 'em all - well, the job just became even harder.