Battling is the core mechanic to the game of Pokemon. And Competitive Pokemon has now emerged as one of the biggest competitive video game sects in the world. As such, there is a certain vernacular that has emerged as commonplace in the world of competitive battling that can make it intimidating and impossible for beginners to jump in and start battling. Therefore, I have put together this little list of terms that are commonly seen in the competitive scene to help you understand what people mean (or should mean) when they use these terms and to help clear up common misconceptions about roles and the sometimes subtle differences between roles that many don't understand.
GENERAL TERMS
Metagame: An all-encompassing term that refers to the competitive pokemon scene as a whole, and also the tiers that make up the game. Example: Stall is still a viable part of the OU Metagame.
Hard Switch: The act of manually switching your Pokemon during a turn. This does not include using moves like Volt Switch and U-Turn, and does not include switching after a Pokemon is knocked out. Example: He brought in Talonflame, so I had to make a hard switch into my Tyranitar.
Switch Initiative: The advantage that arises when you can make a switch while having a general idea what the opponent is about to do. The easiest way to accomplish this is through the use of the moves U-Turn and Volt Switch. The other way switch initiative is gained is by having a Pokemon knocked out and choosing a replacement. Example: Using U-Turn on my Scizor gets me switch initiative throughout the battle.
Check: A Pokemon that can hard switch into an opposing Pokemon and render it ineffective, but not beat it. A check stops an opposing Pokemon's strategy, but cannot actually turn around and beat that opposing Pokemon. Example: Skarmory is a great check to Mega Mawile, because it can stop its attacks and heal up, but can't defeat it.
Counter: A Pokemon that can hard switch into an opposing Pokemon, take its attacks, and beat it one on one. Typing plays probably the biggest role in whether a Pokemon is able to counter another Pokemon. Example: The best counter to Talonflame is Rotom-Wash.
Invest(ment): The amount of EV's placed into a particular stat. Investment simply refers to how much training is put into the stat. Example: The first stat into which a defensive Pokemon should invest is HP.
Core: A group of two or more Pokemon on a team whose typings and characteristics complement each other and provide superior offensive coverage and/or defensive resistances. Cores can be defensive, offensive, or even a combination of the two. Cores constitute the main backbone of your team, so a strong core will lead to a strong team. Example: Heatran, Venusaur, and Rotom-Wash constitute a great Fire/Water/Grass core.
POKEMON ROLES
Sweeper: A Pokemon that is used with the intention of knocking out the majority of the opponent's Pokemon. They can be Specially based, Physically Based, or Mixed (able to use Physical and Special moves on the same set). They often require setup moves such as Swords Dance, and often (although there are lots of bulky sweepers) have considerable speed or else a way of boosting it. Examples: Dragonite, Greninja, Gyarados.
Cleaner: A Pokemon that has the ability to hit a wide variety of Pokemon with its moves that excels at finishing a game by being able to take out weakened Pokemon. A sweeper is designed to take out Pokemon at full health. A Cleaner is something to keep until the game is almost over, and the opponent has Pokemon that have taken considerable damage but aren't knocked out yet. It usually has good Speed and good coverage. Examples: Mega Manectric, Mega Gyarados, Sharpedo.
Revenge Killer: A Pokemon that can switch in after a teammate has been knocked out and knock out or threaten the opposing Pokemon. The Pokemon needs enough speed to outspeed common Sweepers, enough power to knock them out, and the movepool to hit across a broad spectrum. Examples: Garchomp, Deoxys-Speed, Talonflame.
Wall: A Pokemon that has very high defenses and/or a good defensive typing and ability aimed at taking as little damage as possible from an attack. They can be Physical, Special, or Mixed. These Pokemon will often switch in to take a hit and play another defensive role. These roles don't require very much offensive presence, so a wall is the perfect type of Pokemon to fill them. Examples: Skarmory, Blissey, Forretress.
Tank: A Pokemon that has considerable defensive bulk, but a good offensive stat as well. These Pokemon are usually slow, and are aimed at attacking, thus differentiating them from Walls. Examples: Goodra, Tyranitar, Snorlax.
Wallbreaker: A Pokemon that has a very specific moveset aimed at defeating Wall Pokemon. These Pokemon carry some way of defeating common Wall Pokemon so that the Sweeper(s) can have a clear path to win the game. Common strategies include simply overpowering the wall with offensive might, using a mixed attacker to take advantage of the Wall's weaker Defensive stat, or using Taunt to take advantage of the fact that few walls have any offensive presence or attacking moves. These strategies usually utilize a Choice Band or Choice Specs, or are played more to rack up constant damage (in the case of Taunt), so they are not suited for sweeping and should not be run as such. Examples: Mega Garchomp, Mega Charizard Y, Gliscor.
Wish Passer: A Pokemon that carries the move Wish with the intention of passing it to teammates to heal them. Wish is a move that heals half of the user's HP to whatever target is present at the end of the next turn. So if a Pokemon has 400 HP and uses Wish, whatever Pokemon is out at the end of the next turn will receive 200 HP. Very often, Pokemon other than the user that receive the Wish will have less HP than the user, so they get healed at greater than 50%. Examples: Vaporeon, Alomomola, Jirachi.
Cleric: A Pokemon that carries the move Heal Bell or Aromatherapy to heal teammates' status. It's a pretty self explanatory role, this can be what you need to give your sweeper a second shot at winning the game to come back from a seemingly debilitating status infliction. Examples: Umbreon, Florges, Granbull.
Pivot: A Pokemon that can switch into an opposing Pokemon and apply some sort of pressure to the opponent, stopping any momentum they may have and gaining some for your team. While nearly any Pokemon can serve as a pivot, there are a handful of Pokemon that can act as a dedicated one. This can be accomplished through Volt Switch and U-Turn on a slow Pokemon, a typing with a lot of resistances, or a Pokemon with the ability to inflict status or stat drops on an opposing sweeper. Examples: Forretress, Tentacruel, Sableye.
Spinner/Defogger: A Pokemon that carries Rapid Spin or Defog with the intent of removing hazards from your own side of the field. These are almost always a necessity, especially on teams with Pokemon like Talonflame and Charizard. They can be either Offensive or Defensive. Offensive makes it harder to switch into, and Defensive makes it harder to take down. Examples: Forretress, Starmie, Mandibuzz.
TEAMS
There are several playstyles and terms used when referring to entire teams, and those will be covered here.
Balanced: A playstyle in which the amount of offensive pressure on a team is balanced with the amount of defensive capacity of that team. These teams always have 1-2 Sweepers, while the rest of the Pokemon are geared toward removing those Pokemon's biggest threats and weakening the opponents team. This is by far the most popular team in all of the metagame.
Bulky Offense: A playstyle in which the majority of the offensive Pokemon are Tank style Pokemon. Bulky offense relies on the Pokemon's bulk to sponge attacks from the opposition while investing into it's own attacking power to defeat the typically frail sweeper before it secures too many boosts. As these teams are designed to take damage, recovery is generally important to these Pokemon.
Hyper Offense: A playstyle in which at least 4-5 of the Pokemon are very offensive Pokemon, often setup sweepers. A balanced team focuses on clearing a path for one or two sweepers, while Hyper Offense assembles a team of setup sweepers and hopes that one of them will be unchecked by the opponent's team. Sometimes, these teams will carry Hazard support to either break Sturdy and Focus Sash or to protect a vulnerable Pokemon on that team from Hazards.
Stall: A playstyle in which the Pokemon are defensive in nature, and the overarching strategy is to stay alive longer than the opponent, causing them to faint from indirect damage or rendering them useless by running them out of PP. Stall is very difficult to use successfully, especially in today's boosting metagame. Stall teams almost never rely on direct attacks, and instead usually carry Pokemon that spread status (especially Toxic) and the ability Pressure, to stall out PP. They always have reliable recovery on several of their Pokemon, and Leftovers and HP restoring items are crucial.
VoltTurn: A playstyle in which at least 4 of the Pokemon carry either Volt Switch or U-Turn. VoltTurn's success is predicated on Switch Initiative. By constantly using these two moves, the team can stay one step ahead of the opponent's switches and attacks, forcing a lot of switches and minimizing the chances for the opponent to safely switch in their sweeper.
Weather (Sand, Sun, Rain, Hail): A team built around the effects of Weather conditions and the benefits they provide. Weather lasts 5 turns (8 with a boosting item like Damp Rock), so the benefits of the Weather must outweigh the turns spent setting it up. They typically carry at least two Pokemon that can set it, and all of the other Pokemon should be at the very least not affected or inhibited by the effects of Weather.
Trick Room: A playstyle built around the effects of Trick Room. Fairly simple, these teams count on their members being as slow as possible, because under Trick Room, the slowest Pokemon moves first. The major drawback is that Trick Rpom only lasts 5 turns, limiting how non-setting members can utilize this effect.
Gravity: A playstyle built around the effects of Gravity and the benefits it provides. Gravity does two things. First, it brings Flying type and Levitating Pokemon down to the ground, not losing their Flying typing but making them vulnerable to Ground attacks and all forms of entry Hazards. Second, it lowers the evasion of all Pokemon to 60%, essentially raising accuracy by 5/3; i.e., a 60% accurate move will now become 100% accurate. Like Trick Room, it only lasts 5 turns with no way to extend it, so it's tough to pull off.
Baton Pass: A playstyle in which at least 5 Pokemon know Baton Pass and the goal is to pass boosts from Pokemon to Pokemon and either maintain the boosts or pass them to a receiver. This is a style that can have variety, but unfortunately, there is a recipe for success that is used very often, causing it to be deemed noncompetitive and nerfed by Smogon. The only true counter to the team is Unaware Clefable and Quagsire, and those are shaky at best.
