Shiny Pokémon are Pokémon that have an unnatural coloration. The coloration can be mild, only a few shades darker or lighter than the original, or drastic. They are not to be confused with Boss Pokémon, which are tinted differently than Shiny Pokémon and cannot be caught. Each Pokémon has a very rare (1 by default) chance of being Shiny, and Shiny Pokémon are much sought after for their unique look and rarity.
A Shiny coloration gives no advantage in battle, with the effect being purely cosmetic. A Shiny Pokémon will emit particles and have a star under its level while in battle with a trainer. Shinies will have a golden name tag as well. Wild Shiny Pokémon will not engage in battle with other wild Pokémon.
If two breeding Pokémon have differing original Trainers, their Eggs have double the normal chance of hatching into Shiny Pokémon. You can also increase the chance of Shiny Pokemon appearing by using a Shiny Charm, increasing the chance of them appearing from 1/4096 to 3/4096, roughly around 1/1365. Another way to increase shinies appearing is to use a Weak Shiny Lure for a 1.22x shiny multiplier, or a Strong Shiny Lure for a 1.73x shiny multiplier.
- "Shiny spawn rate": The rarity of Shiny Pokémon spawning in the wild (1).