When referring to Pokémon in the competitive sense, terms such as OU, UU, PU, etc. get thrown around. None of these terms are found within the Pokémon games or in the VGC itself, leaving many players unsure of what they mean. These terms come from Pokémon Showdown, a downloadable computer application that can also run through a browser and allows for competitive Pokémon battles with people around the world. The game allows for varied teambuilding and metagames for players to hone their skills and feel the effects that different features have on any particular format.
Pokémon Showdown, which first came out in Oct. 2011, was adopted by Smogon, an online resource for competitive Pokémon, in July 2012. Pokémon Showdown is completely free to play and lets players create a profile and save their own teams, as well as check their rankings in comparison to other players. At any given point there are likely to be over 10,000 players online and over 2,000 active battles.
One of the biggest draws to Pokémon Showdown is teambuilding. Unlike the mainline Pokémon games, players do not actually have to acquire their perfect IV Pokémon and EV train them with the proper egg moves. Showdown allows the player to just choose what they want as long as it is something that they'd hypothetically be able to acquire, no matter how unlikely. This is helpful to anyone who wants to get into the competitive scene, as it allows them to get started right away and avoid the tedious process that would otherwise be raising a Pokémon.
On top of this, the teambuilder within Showdown will notify the player if something is wrong. Whether there is a Pokémon with an illegal move, a Pokémon not allowed in that specific format or a Pokémon missing EVs, the teambuilder informs the player, allowing them to fix the problem before actually playing.
Showdown also allows players to try out different formats and metagames, which each have their different rules. These formats range from the basic OverUsed (OU), UnderUsed (UU), RarelyUsed (RU), NeverUsed (NU), PU (a pun meaning that the tier is bad) and ZeroUsed (ZU) of the most recent games, such as the current Sword and Shield formats. Players can also choose between singles or doubles for many of the current metas. Each of these formats has its own set of Pokémon that are allowed and not allowed.
For example, a Pokémon such as Conkeldurr is currently in the Sword and Shield UU tier, meaning that it is available in UU, OU, and Ubers, but is an illegal choice for the RU and below formats. This allows each format to feel fresh and unique as they have their own set of Pokémon to use, each having unique quirks about how the format-specific Pokémon all come together to create a unique meta. They track the player's ranking separately, allowing one to track their own skill between the different formats.
For those looking to spice up their gameplay, Showdown also has a host of other formats for players to try. There are simple options such as Random Battles (which randomizes each player's team) and Monotype (where players can take on the role of gym leaders and fight other teams with a common typing). There are also more wild options, like Sketchmons (which allows Pokémon to learn almost any move) and Godly Gift (which allows one Uber onto a team). With Godly Gift, all other Pokémon on the team have one of their stats changed to that of the Uber, depending on which slot they are in. There are dozens of these metagames that rotate each month -- each allows players to try out new strategies and use their creativity to craft a team they'd otherwise be unable to.
Pokémon Showdown continues to grow in popularity, and it isn't hard to see why. Almost every fan of the series can find something they'll enjoy within it, and it doesn't come with many of the hurdles found in normal Pokémon games. While some may enjoy the grind of perfecting a Pokémon, many do not, and Showdown is the perfect home for those players.
