* Klefki has access to a large number of support options, in particular Spikes, Thunder Wave, Reflect, Light Screen and Magnet Rise.
* Its wide movepool in tandem with Prankster allows it to function as a very effective support Pokemon.
* Prankster Thunder Wave means that Klefki can act as a check to the majority of setup sweepers.
* A Light Clay set with dual screens ensures that its teammates can more reliably set up.
* Fairy / Steel typing gives Klefki two key immunities and nine different resistances, which grants it more opportunities to switch in and set up Spikes or screens.
* 57/91/87 defenses mean Klefki cannot take hits well.
* Dark-types gaining an immunity to Prankster means that Klefki has to run Fairy-type STAB moves if it wants to be able to even touch Dark-types.
* Weaknesses Fire and Ground further reduce its longevity, although the latter is somewhat remedied by Magnet Rise.
* Incredibly passive; 80/80 offenses give it little to no presence offensively.
move 1: Spikes
move 2: Thunder Wave
move 3: Play Rough
move 4: Foul Play / Magnet Rise
item: Leftovers / Sitrus Berry
evs: 252 HP / 252 SpD / 4 Def
* Spikes is a great support move in general and it allows Klefki to slowly rack up damage on the opposing team's Pokemon, punishing any switches.
* Thunder Wave is also crucial for its ability to permanently halve the Speed of faster threats, as well as stop setup sweepers in their tracks.
* Play Rough allows Klefki to actually hit Dark-types, as they're immune to Prankster, in particular Mega Sableye.
* Foul Play hits Jirachi for good damage, while also discouraging sweepers like Excadrill and Scizor, who don't mind a Thunder Wave, from setting up.
* Magnet Rise turns Klefki's weakness to Ground into an immunity for five turns, which gives it more time to set up Spikes and can force out Pokemon which normally rely on Ground-type moves to check it, like Garchomp and Excadrill.
* Full investment into HP EVs is necessary to maximize Klefki's longevity on the battlefield.
* 252 EVs are placed into Special Defense to allow Klefki to shrug off special hits from Pokemon like Starmie, Clefable, Keldeo, Latios, Latias and Tornadus.
* The rest of the EVs are thrown into Defense to increase physical bulk.
* A Careful nature is used to further increase Klefki's Special Defense while dropping its unused Special Attack.
* Leftovers is the item of choice to give Klefki some passive recovery while it places Spikes.
* Sitrus Berry is also viable to provide Klefki with immediate recovery as soon as it falls to below half of its HP.
* Prankster is the only real reason to use Klefki for priority on all of its Status moves.
* A spread of 252 HP / 252 Def / 4 SpD with a Bold nature and a Rocky Helmet can be used to better take on physical attackers like Weavile, Azumarill and Tapu Bulu.
* Due to how passive Klefki is, it can easily be taken advantage of, particularly by setup sweepers who are immune to its Status moves. As such, it should be switched out often in order to avoid giving free turns to the opposing team if at all possible.
* Klefki should be switched in to tank a hit with one of its numerous resistances or immunities and set up Spikes.
* Klefki can be sent in to use Thunder Wave on a setup sweeper and stop a potential sweep, but generally only when it gets a free switch, as Klefki cannot afford to take too many hits.
* Spikes or Toxic can be used on a predicted switch into a Pokémon immune to Thunder Wave.
* Magnet Rise should be selected if a Ground-type, such as Garchomp, Landorus-T or Excadrill, decides to switch in on Klefki.
* Foul Play should be used on physical set up sweepers to discourage them from using boosting moves.
* Klefki is a fairly specialized Pokemon which fits mostly on more offensive teams which appreciate the Spikes support to help wear down their checks and counters and gain more KOs.
* Pokemon such as Mega Scizor and Mega Sharpedo, make for good partners as their checks are mostly grounded Pokemon that are worn down by Spikes.
* Gyarados and Mega Gyarados are excellent teammates for Klefki, as Spikes allows them to wear down checks like Mega Manectric and Magnezone. They also have good defensive synergy with Klefki, able to switch in on Fire- and Ground-type moves.
* Defiant users, the two most relevant in OU being Bisharp and Thundurus, work well with Klefki because they discourage Defoggers from getting rid of Spikes.
* Water-types in general make decent partners for their ability to wear down the Fire- and Ground-types which threaten Klefki.
* Metal Sound, Flash Cannon, and Dazzling Gleam allows Klefki to break through bulky Calm Mind users, such as Clefable, Slowbro, and Keldeo.
* A dual screens set with Fairy Lock makes for a useful partner for most setup sweepers.
* Z-Psych Up has a niche in restoring Klefki's HP to full, but is only usable once and once used is mostly a waste of Klefki's item slot and one of its move slots.
* Dazzling Gleam can be used over Play Rough to hit physically defensive walls harder.
Checks and Counters
**Ground-types**: Ground-types are immune to Thunder Wave and can easily beat Klefki with a super effective STAB move.
**Electric-types**: Electric-types like Magnezone and Tapu Koko also can’t be touched by Thunder Wave and so can pretty easily switch in on Klefki and sometimes even set up on it
**Ferrothorn**: Ferrothorn is immune to Toxic and a Thunder Wave only makes Gyro Ball stronger. It takes little from Play Rough or Foul Play, meaning that it can easily use Klefki to set up entry hazards or get up Leech Seed.
**Excadrill**: Excadrill is able to shut down Klefki as it's immune to Thunder Wave and Toxic and can easily Rapid Spin away any Spikes Klefki might set up against it.
**Tapu Fini**: Misty Terrain being on the field stops Klefki from using both Spikes and any kind of status-inflicting move it might carry, meaning that Tapu Fini has to be eliminated before Klefki can do it's job effectively.
**Taunt Users**: Taunt users can shut Klefki down, though most of them, except Thundurus, have to watch out for priority Thunder Wave.
**Defensive Pokemon**: Klefki generally has a harder time dealing with bulkier Pokémon like Rotom-Wash, Heatran and Slowbro. It can beat theme with Toxic or Heal Block though.