Gengar

Levitate
This Pokémon is immune to Ground-type moves.
Type Tier
Ghost / Poison OU
Statistics
Min- Min Max Max+
HP
60
- 261 324 -
Atk
65
149 166 229 251
Def
60
140 156 219 240
SpA
130
266 296 359 394
SpD
75
167 186 249 273
Spe
110
230 256 319 350
Name Item Nature

Standard

Life Orb Timid
Moveset EVs
~ Shadow Ball
~ Thunderbolt
~ Focus Blast
~ Hidden Power Fire / Explosion
4 Def / 252 SpA / 252 Spe

Gengar is a major threat, and with good reason. With base 130 Special Attack and 110 Speed, as well as a great STAB type and good type coverage, Gengar is capable of dealing heavy damage to the opponent's team. Gengar also has three extremely useful immunities to Ground, Normal, and Fighting to work with, allowing it to switch in against Pokémon such as Scarf Flygon locked into Earthquake, Choice Band Machamp locked into DynamicPunch, or Choice Scarf Heatran locked into Earth Power. Shadow Ball and Focus Blast give Gengar complete type coverage and hit some of the metagame's top threats for super effective damage. Focus Blast always OHKOes max HP Tyranitar in sandstorm; however, Gengar should be cautious due to Focus Blast's shaky 70% accuracy. It also does a good amount of damage to standard Snorlax and always OHKOes min HP Heatran. Thunderbolt offers a quick OHKO against Gyarados and 2HKOes max HP Suicune.

Hidden Power Fire OHKOes Scizor and deals 59.34% - 70.33% to max HP Metagross. It should be noted that by running Hidden Power Fire, Gengar is forced to have an imperfect Speed IV, which means that it will almost always lose the speed tie against opposing Gengar and Latias. 40 Attack EVs and a Hasty nature (92 Attack EVs when using Timid nature) are recommended when using Explosion, allowing Gengar to OHKO standard Blissey after Stealth Rock (watch out for Protect though). Hypnosis could be used in the final slot, however its low accuracy makes it a less than ideal option. It is one of Gengar's best options against Blissey, who does not threaten Gengar immediately with Flamethrower or Ice Beam. Gengar should watch out for Thunder Wave though.

Without Hidden Power Fire, a lot of Steel-type Pokemon in the game - Scizor, Metagross, and Jirachi, to name a few - can come in on most of Gengar's attacks and threaten it with their STAB attacks. Metagross can easily dispatch it with Meteor Mash, while Jirachi can paralyze it with Thunder Wave or send it to oblivion with repeated hits with Iron Head. Scizor gets particular mention as it can take down Gengar with a swift Bullet Punch, or punish a fleeing one with Pursuit. Without Explosion, Blissey can entirely wall this set, paralyze Gengar with Thunder Wave, and even start weakening it with one of her special attacks. Choice Scarfed versions of Heatran can come in on Shadow Ball or get a Flash Fire boost from Hidden Power Fire and proceed to easily KO Gengar with Fire Blast.

Since most of Gengar's counters are Steel-types, Magnezone makes for a great partner. Not only can it trap and take down Scizor, it can also utilize a set with Magnet Rise and Substitute to deal with both Metagross and Jirachi. Gengar is also immune to the Fighting- and Ground-type attacks that are commonly directed at Magnezone, should you not want to run Magnet Rise. Ironically, a Scizor of your own can be of great help to Gengar, as it can slowly weaken Gengar's common counters with its ever-broke U-turn attack. Scizor can also come in on Blissey without really minding paralysis and then use Superpower for the OHKO or heavily damage a fleeing Blissey with Pursuit. A Pokemon that can take on both Heatran and the other Steel-types well is Swampert. Swampert can easily come in on most Heatran and scare it off with Earthquake or Waterfall, netting you a free turn to set-up Stealth Rock. Swampert can also deal with most of the Steel-type Pokemon that threaten Gengar with its STABed Earthquake.

Name Item Nature

Choice

Choice Scarf / Choice Specs Modest / Timid
Moveset EVs
~ Shadow Ball
~ Thunderbolt
~ Focus Blast
~ Hidden Power Ice / Trick / Explosion
4 Def / 252 SpA / 252 Spe

Odd though it may seem to use Choice Scarf on something as fast as Gengar, this set has some very alluring advantages. Gengar's varied movepool lets it act as an effective revenge killer against some of the biggest threats in the game; Azelf, Tyranitar, Gyarados (including bulky varieties), and Salamence will all fall in one hit to their corresponding moves if they lack significant defensive investment or type-resisting berries such as the Wacan Berry. Choice Scarf Gengar is by no means a counter to such Pokémon, but it can easily save you the match should you make an error and let your Gyarados counter be KOed by something like Pursuit.

When you're finally tired of or no longer need to revenge kill any of your opponent's Pokémon, Gengar can then relieve itself of the penalties of its Choice Scarf at the expense of one of your opponent's Pokémon with the move Trick. This cripples most of Gengar's common switch-ins like Blissey and Snorlax by swapping their Leftovers for your Choice Scarf and more or less making them a burden for your opponent for the remainder of the match. Trick can also be used in lieu of Thunderbolt, as Trick cripples most targets of Thunderbolt anyway (Skarmory for example).

Explosion (preferably used with a Mild or Hasty nature) allows you to revenge kill a large number of Pokémon with one move as well, but don't expect to beat Blissey without a significant amount of investment in Attack or some previous damage.

Alternatively, this moveset is also ideal for Choice Specs Gengar. With such high Speed and Special Attack stats, Choice Specs is indeed a fearsome item on an opposing Gengar. In comparison to the Choice Scarf set, you won't be outspeeding Pokémon like Weavile or a once Dragon Danced Salamence here, but you'll pack way more power so neither can afford to switch in safely, nor can much else. Timid is the nature of choice here, as without a Choice Scarf you're going to want Gengar to be outspeeding as much as possible.

Along with the aforementioned Steel-types, a Pokemon that can easily deal with Choiced Gengar is Tyranitar. With Sandstorm bolstering its above average Special Defense stat, Tyranitar can easily come in on anything bar Focus Blast, and then end Gengar's sweep with Pursuit. Tyranitar, however, can be easily stopped by Swampert, while Gliscor also makes a very fine switch-in as it can take on most of Tyranitar's attacks and give it a heavy blow with Earthquake. Snorlax is in a similar boat with Tyranitar, as it can come in on Gengar with its respectable Special Defense and KO it with Pursuit.

Defensive Pokemon such Celebi, Jirachi, Suicune, and Cresselia can all come in on resisted hits and then start setting-up as they force Gengar to switch out. Celebi can paralyze one of your Pokemon, Jirachi and Suicune can start boosting their stats with Calm Mind, and Cresselia can set up both Reflect and Light Screen to weaken your attacks and help set-up for an eventual sweep. As such, having a Pokemon that can deal with such threats, such as a Suicune of your own, would be necessary. As they start setting-up, Suicune can set-up alongside of them, Roar them out, and then get ready to sweep their team. Suicune is also capable of taking on the Steel-type moves that Gengar hates with ease, as it is resistant to them and has naturally high Defense.

Name Item Nature

Substitute + Focus Punch

Expert Belt Hasty
Moveset EVs
~ Shadow Ball
~ Substitute
~ Focus Punch
~ Hidden Power Fire / Hypnosis / Explosion
100 Atk / 156 SpA / 252 Spe

Substitute allows Gengar to deal with the Pokémon that commonly switch into it — namely Blissey, Scizor, and Snorlax.

Substitute not only blocks status and eases prediction, but allows Gengar to Focus Punch without risk of being hit. Focus Punch with the given EVs and item deals 63.29% - 74.81% to 0 HP / 252 Def Calm Blissey and 53.08% - 62.46% to 252 HP / 252 Bold Blissey, both a 2HKO even when factoring in Leftovers recovery (however, Bold Blissey can avoid the 2HKO with Protect). Focus Punch also deals 62.23% - 73.37% to min HP Heatran, meaning Stealth Rock followed by Focus Punch and Shadow Ball has a small chance of KOing.

Normally, Gengar should Substitute first turn, allowing it to OHKO Scizor hoping to OHKO with Bullet Punch or Forretress with Gyro Ball. Once behind a Substitute, Gengar can more safely use Hypnosis without fear of retaliation. Once the opponent is safely asleep and Gengar is behind its Substitute, it can begin to wreak havoc with the unresisted type coverage provided by Focus Punch and Shadow Ball.

Expert Belt is chosen over Leftovers for one main reason: it saves Gengar from having to transfer a significant amount of Special Attack EVs into Attack (because Blissey and Snorlax are hit super effectively by Focus Punch), which would significantly lower Shadow Ball's damage on common neutral threats like Salamence and Gyarados. The lack of any kind of recovery is a non-issue too because Gengar can switch in numerous times on one of its many immunities (hopefully only ever taking damage from Stealth Rock).

Explosion can be used in the final slot in place of Hidden Power Fire, allowing Gengar to go out with a literal bang, dealing more damage than normal due to the investment in Attack.

Although this set can be dangerous, it doesn't have the raw power that the standard set has. The bulky Pokemon mentioned earlier all fair well against this set, although they should to be wary of being put to sleep by Hypnosis. That said, another Pokemon that can be very troublesome to this set is Spiritomb. Its dual Ghost- and Dark-typing makes it both immune to Focus Punch and neutral to Shadow Ball, and with its respectable Special Defense it can take on Gengar's attacks with ease and use Pursuit or Dark Pulse to inflict massive damage. A weakened Spiritomb can also take on Gengar with Sucker Punch, possibly finishing the latter off.

Heatran can usually take on most of the bulky Steel-types that this Gengar has trouble with. Since Spiritomb occasionally carries Will-O-Wisp, Heatran can come in and grab a Fire Flash boost and then start spamming over-powered Fire Blasts that can open holes in your opponents team, possibly allowing you to end the game with an easy win.

Name Item Nature

Substitute Special

Leftovers Timid
Moveset EVs
~ Substitute
~ Shadow Ball
~ Focus Blast
~ Hidden Power Fire / Hypnosis
4 HP / 252 SpA / 252 Spe

Substitute is an excellent move on Gengar and serves a multitude of purposes. On something as frail and susceptible to Pursuit and priority attacks as Gengar, having an "extra life" beyond those meager defenses is a great asset. It helps it deal with Tyranitar and Scizor, two of its greatest threats, by scouting their switch in with Substitute and then hitting them with the respective 4x super effective attack. Substitute also allows you to evade status, meaning you don't need to fear paralysis from Celebi, among others.

Shadow Ball and Focus Blast pair up to give Gengar the unresisted Ghost / Fighting coverage, and Focus Blast in particular is essential for dealing with any Tyranitar or Weavile that try to come in and Pursuit you. Hidden Power Fire in the last slot grants Gengar a quick OHKO on Scizor and Forretress, as well as giving it a way of hurting Skarmory without having to risk Focus Blast's poor accuracy. However, another very viable option for the last slot is Hypnosis. With its unreliable 60% accuracy, it is a risky move to try and use on a standard Gengar set. Substitute, however, effectively gives Gengar two shots at sleeping an opponent, and Hypnosis has a reasonable 84% chance to hit at least once out of two uses. The fact that it is so unexpected from Gengar anymore makes it all the more effective. Hidden Power Fire is useful but not essential, as Focus Blast hits Scizor plenty hard anyway, meaning Hypnosis is a useable option as well. Alternatively, you can play this Gengar just like the standard sweeper set but with Substitute, and so go with Thunderbolt in the last slot to get the super effective hit on bulky waters and Gyarados.

Even without a specific boosting item, Gengar gets the KOs it needs to. Focus Blast OHKOes 252 HP Tyranitar after taking Stealth Rock damage, and the bulkier 252 HP / 216 SpD Careful Tyranitar won't be OHKOed even by a Life Orb Focus Blast. However, this Gengar has the advantage of Substitute, usually giving it two shots against Tyranitar if Focus Blast's accuracy lets it down the first time. Leftovers provides a reliable source of healing for Gengar and helps offset the HP loss from Substitute. It also means that in a sandstorm, Gengar won't be losing obscenely large amounts of health to residual damage. There are other item choices for this set, such as Wide Lens to slightly increase the chances of Hypnosis and Focus Blast hitting, and Petaya Berry to turn Gengar into a deadly sweeper when at low health, but usually Leftovers is the best item to have. The advantages of using this Gengar over a similar set utilizing Substitute and Focus Punch are that it is not required to run Expert Belt and split its offensive EVs, and it can use Focus Blast to revenge kill threatening Pokémon such as Lucario and non-Scarf Heatran.

Most of what deals with the Focus Punch + Substitute set above fairs well against this set. Special mention goes to Blissey, as it can take on Focus Blast with ease and then recover the damage. Another great Pokemon capable of dealing with Gengar is a specially defensive Zapdos. It can come in on Gengar, get rid of any damage it has with Roost, set up Light Screen, and proceed to deal with Gengar with its STAB attacks.

Name Item Nature

MYSTICgar

Life Orb Timid
Moveset EVs
~ Protect
~ Shadow Ball
~ Focus Blast
~ Hidden Power Fire
4 Def / 252 SpA / 252 Spe

Shadow Ball, Focus Blast, and Hidden Power Fire give Gengar great coverage, and Protect allows for general scouting. Life Orb is necessary, as many Choice Band Tyranitar run a lot of Special Defense, and without Life Orb the OHKO with Focus Blast is nonexistent. The EVs maximize Speed so that Gengar can both outspeed Adamant Choice Scarf Scizor and Infernape and have a 50% chance of outspeeding other Hidden Power Fire Gengar.

Protect allows Gengar to defeat most versions of the two Pokemon that give it the most difficulty in the Platinum metagame: Pursuit Tyranitar and Bullet Punch + Pursuit Scizor. After Gengar has switched in and Tyranitar or Scizor have then switched in as well, Gengar will first use Protect to see if Tyranitar or Scizor uses Pursuit. If either Pokemon uses Pursuit, Gengar will use the proper move to OHKO it. If neither Pokemon uses Pursuit, Gengar can safely switch out. Note that even with Protect, Gengar needs to remain wary of non-Choiced Scizor with Bullet Punch and Pursuit and Choice Scarf Tyranitar with Pursuit.

This specific version of Gengar acts as a great lure for many of Gengar's counters. As such, having a Pokemon that benefits from having Pokemon like Scizor eliminated makes for a great partner. Gengar lures out and eliminates Scizor, for example, and then Pokemon like Latias can sweep easier, as one of its main counters has been eliminated. Latias can also greatly enjoy Tyranitar being significantly weakened or even eliminated by a a super effective Focus Blast from Gengar. Other offensive Pokemon such as Salamence and Tyranitar can significantly benefit from there counters weakened, and thus are great partners.

It should be noted that Pokemon that can beat the aforementioned counters should be also considered as partners for this Gengar. For example, Gengar can OHKO a Scizor with Hidden Power Fire if it uses Pursuit, but will need a Magnezone to trap and eliminate a Scizor that is using Bullet Punch.

Name Item Nature

Ubers Choice Scarf

Choice Scarf Timid
Moveset EVs
~ Shadow Ball
~ Hidden Power Ice
~ Focus Blast
~ Trick
4 HP / 252 SpA / 252 Spe

Gengar’s high Speed and useful typing make it a great Choice Scarfer in OU as well as Ubers. Gengar functions very well in Ubers because of its ability to check many common threats while holding a Choice Scarf and its immunities to types like Fighting, Normal, and Ground.

Hidden Power Ice is extremely effective, and can be used to eliminate threats such as Rayquaza, Garchomp, Shaymin-S, or even Jumpluff (when there is no sun). Shadow Ball, however, will be your main attacking move, as it hits a huge amount of the tier for super effective damage (Pokémon like Mewtwo, Latios, Latias, Giratina, and more) plus it gains STAB. This works out to 240 Base Power, compared to 210 Base Power from a STAB Draco Meteor (albeit Gengar has 20 less base Special Attack than Dialga or Palkia); it also does not cause your Special Attack to drop by two stages.

Focus Blast can hurt a few leftover Pokémon, such as Darkrai and Lucario. Choice Scarf Gengar outspeeds both of these Pokémon (unless Darkrai has a Choice Scarf), so Gengar can easily come in on a free turn, or after one of your Pokémon has fainted, to stop their sweep. However, you must always be wary of Focus Blast’s rather lackluster 70% accuracy, so it should be used only when necessary. Trick can be used as a last ditch effort, and only should be considered when Gengar is low on HP or if it is truly imperative to cripple an opponent, as Gengar will mostly be dead weight without its Speed-boosting item. Trick can cripple walls, such as Lugia, Giratina, or Blissey (who gives Gengar massive problems in particular); stat-boosting sweepers or sweepers reliant on wide coverage, by preventing them from using their stat-boosting moves or switching moves; or, possibly most importantly, Wobbuffet.

Gengar does not need much support itself, since, as a revenge killer, it will mainly be picking off already weakened enemies. However, it will be as good as dead if you do not take precautions by eliminating your opponent’s Pursuit-users. The most common users of Pursuit in Ubers are Scizor, Tyranitar, and, to a lesser extent, Metagross. Scizor, who is the most common of the lot, can be handled by a luring Mewtwo who has Fire Blast. Many Scizor will normally switch into Mewtwo, as it is normally quite vulnerable to Scizor, only to be met with a Fire Blast, which will OHKO it. Metagross can be dealt with in a similar way. Tyranitar is also always 2HKOed by an Aura Sphere from Mewtwo (assuming that Tyranitar has maximum HP and Special Defense EVs with a Careful Nature). Another Pokémon who can deal with these threats is Calm Mind + Rest/Sleep Talk Kyogre. With Kyogre’s large bulk, access to Rest + Sleep Talk, and resistance to Steel-type, it can Calm Mind in the face of these threats and Rest when necessary. Then, it can use its boosted Surf to eliminate these threats. The only Pokémon of Scizor, Metagross, and Tyranitar who can threaten Kyogre is Metagross’s Explosion. While this will end up with Kyogre being defeated, it is also a way (albeit slightly perverse) of getting rid of Metagross.

Gengar’s biggest ways of helping its teammates are by freeing up positions on the team and by crippling Wobbuffet. By having Gengar as a revenge killer who can revenge kill many of the Uber metagame’s most deadly sweepers, you can let other would-be revenge killers, such as Palkia or Dialga, take on other roles on your team, such as mixed sets, which help your team fight stall. Also, by crippling Wobbuffet with Trick, you can prevent it from using its Encore + Counter/Mirror Coat combo, or stop it from setting up a sweeper. Furthermore, because it is locked into one move, it becomes much easier to predict around its Mirror Coat or Counter. Similarly, by crippling a wall, such as Blissey, with its Choice Scarf, Gengar can prevent it from doing its duties properly, therefore making it easier for Pokémon to sweep. In the example of Blissey, it becomes much easier for Pokémon like Calm Mind + Rest / Sleep Talk Kyogre to sweep if Blissey can only do one thing before switching out. Gengar can also revenge kill Dragon-types who are locked into Outrage, more specifically, Garchomp and Rayquaza. If you eliminate these threats, it will be much easier for a Dialga or a Rayquaza or Garchomp of your own to sweep, as they become much harder to revenge kill.

Name Item Nature

Ubers Life Orb

Life Orb Timid
Moveset EVs
~ Shadow Ball
~ Icy Wind
~ Focus Blast
~ Hidden Power Fire
4 Def / 252 SpA / 252 Spe

This Gengar’s function is twofold: it is a revenge killer who can switch moves, and it is a lure. While this set may seem inferior to the Choice Scarf set, the power boost from Life Orb and the ability to switch moves, without switching out, should not be underestimated.

With the power boosted granted from Life Orb, Gengar can OHKO Rayquaza 100% of the time with Icy Wind, as long as Stealth Rock is down (about 80% of the time without). Because of this, Gengar can now use a Hidden Power that is not Ice-type. Furthermore, Icy Wind has the beneficial side effect of lowering your opponent's Pokémon's Speed by 1 stage. This allows Gengar to outspeed all Pokémon who reach a Speed stat of 522; this includes all base 100s with a +Speed nature and a Choice Scarf. By using Hidden Power Fire, Gengar can eliminate its biggest counter: Scizor. Choice Band Scizor (and therefore Trapper Scizor as well) is OHKOed by Hidden Power Fire even when the sun is not out; however, it is only a 2HKO in the rain. Make sure you hit it on the switch in though, or make your opponent think that you will switch, since Bullet Punch will OHKO after LO and Stealth Rock damage. Metagross, on the other hand, is 2HKOed by a Hidden Power Fire with no weather (in the sun it has a small chance to OHKO, but its only a 3HKO in the rain). Tyranitar is also handled more easily, as now Gengar can simply use Focus Blast without switching out (theres a 100% of an OHKO even when Tyranitar has maximum HP and Special Defense and a +SpD nature, as long as there is Stealth Rock and a layer of Spikes up).

Protect and Explosion are other possibilities for the set. Protect allows you to scout whether Metagross or Scizor are using Bullet Punch or Pursuit; this allows you to predict correctly as to whether or not to stay in and use Hidden Power Fire. Protect also just aids prediction in general. Explosion can be used as well, and it serves as a “last ditch” attempt to KO one of your opponent’s Pokémon; make sure to use a Hasty nature though. It will do tremendous damage to any Pokémon who is not immune or resistant to it (Blissey will be OHKOed, and max HP Kyogre and Ho-oh will be OHKOed after they take Stealth Rock damage). Explosion does, however, come with the obvious drawback of causing Gengar to faint as well. Both Protect and Explosion are hard to fit on this set because of each move’s importance.

Since Gengar will be eliminating mainly Scizor and Tyranitar, it will be much easier for certain Pokémon to sweep or wall. Some Pokémon who will benefit from this are Mewtwo, Darkrai, and Lugia. A Calm Mind Mewtwo is normally stuck when facing Scizor, as Scizor resists Ice Beam and takes neutral damage from Aura Sphere (the two most common attacks) and can hit back for super effective damage with U-turn or Pursuit. Likewise, Nasty Plot Darkrai is usually in a pickle against Scizor, unless the Sleep Clause is not activated, or if Darkrai has near full health. Scizor can use U-turn or Superpower on it for super effective damage or Bullet Punch it for priority, as it is only truly threatened by a +2 Focus Blast (which also has a large chance of missing). Lugia can also play a much larger role in teams, whether it be sweeping or walling, after Tyranitar has been eliminated. Not only does Tyranitar deal huge amounts of damage to Lugia with Crunch, Stone Edge, or Pursuit, but it also brings the sandstorm, which chips away at Lugia’s health and boosts its own Special Defense (then Lugia’s Ice Beam will only deal about 9%). Since Gengar deals with both Scizor and Tyranitar, it will be much easier to use Mewtwo, Darkrai, and Lugia after Gengar has done its job.

Team Options

OU

Gengar is a fast and destructive Pokemon, albeit very frail. Usually, any neutral STAB attack from the opponent can take out a big chunk of Gengar's health, and maybe even OHKO it. That said, Gengar tends to benefit from almost any Pokemon that can deal with or at least weaken its counters. Stealth Rock can also help Gengar secure some OHKOs or 2HKOs that would otherwise be hard to get. Gengar also has a great typing and one of the most useful abilities in the game - Levitate. Having an immunity to some of the most abundant moves in the game - Earthquake and Earth Power - means that Gengar generally tends to come in on its immunities rather than on resisted hits. This means that not only Gengar but also most of its Steel-type partners can benefit from its immunities to Ground- and Fighting-type moves.

As previously mentioned, most of Gengar's partners tend to be Steel-type Pokemon. Magnezone is one of Gengar's most beneficial partners as not only can it eliminate most Steel-types that give Gengar lots of trouble, but also resists Steel-, Ghost-, and Dark-type moves that hit Gengar for super effective damage. Gengar is also immune to the Fighting- and Ground-type attacks that Magnezone fears. Most of the aforementioned Steel-type Pokemon are great partners to Gengar as they can at least weaken most of its counters, possibly allowing an almost unhindered sweep.

On the offensive side of the game, Pokemon like Infernape and Salamence are great partners to Gengar, as they are fantastic wall-breakers that can severely cripple most of Gengar's counters. For example, Infernape can easily OHKO Tyranitar, Scizor, Blissey, Snorlax, and most other general walls that Gengar has trouble with. Scizor is also another great partner that can deal with most of the above Pokemon. Gengar Pokemon like Latias have common counters, meaning that if one of them can at least weaken its counters, the other Pokemon can have a field day against the opponent's team.

Ubers

As with all offensive Pokémon, Gengar appreciates the additions of entry hazards, especially Stealth Rock and Spikes. They do immediate damage, and Gengar cannot afford to wait for its opponent to die to mounting poison damage from Toxic Spikes. The most notable Pokémon who can set this up are Deoxys-S, Deoxys-A, Forretress, Dialga, and Groudon. All of these Pokémon can work excellently as leads, and Groudon or Forretress can work well as general supporters throughout the match. However, if you choose a Deoxys forme, then you must be especially careful, as both Deoxys and Gengar are weak to Dark-type moves (Pursuit in particular); this goes especially for Deoxys-A, who has horrible defenses (although if Deoxys-A has a Focus Sash it can KO Scizor with Fire Punch). If you are using a Fire-type move then you should consider including Groudon on your team. If you decide to stay in on Scizor to kill it with Hidden Power Fire, you should make sure that it will KO it, or else Gengar will be taken out by Pursuit. Furthermore, Groudon’s sun will cancel out the possible sandstorm (or the rare hail), which will only add to Gengar’s recoil per turn. This even further weakens an already weak Pokémon.

Like many Pokémon who use special attacks, Gengar will have problems facing special walls, such as Blissey (unless it has Explosion). Not only does Blissey take very little damage from most of Gengar’s moves, but also she is immune to Shadow Ball, Gengar’s most powerful move. Therefore, be sure to use a Pokémon who can break Blissey with powerful physical attacks. Dialga or Palkia are both good choices, as they are normally thought of as special attackers, so mixed versions can surprise Blissey with physical attacks. Groudon is also a good choice, as it can hit Blissey with Earthquake, as well as absorbing Thunder Waves that are aimed at Gengar, which would ruin its effectiveness; Gengar can also absorb Toxics in return. Another possibility is to use the combination of Tickle Wobbuffet and a Pursuit-user, such as Scizor or Tyranitar. By using Tickle four times, an Adamant Scizor with 100 Attack EVs and a Life Orb will OHKO Blissey as she switches out; Blissey must be Tickled twice for a Tyranitar with 56 Attack and a neutral nature to KO her while she switches out. Since now your team has a Dragon Dance / Swords Dance Rayquaza counter in Gengar, it is possible for Palkia or Dialga, respectively, to use a set other than Choice Scarf. By using mixed sets, they can not only help Gengar (as mentioned above), but they can also obliterate stall teams, which give many sweepers, such as Rayquaza, Darkrai, or Lucario, problems. Finally, defensive Kyogre sets can pose problems, as Kyogre's base HP and Special Defense stats are deceptively large. Without Thunder or Explosion, Gengar will struggle to deal damage with Kyogre, while Kyogre can just Surf it to death, or set up Calm Minds while Resting off any damage that it might attain. Any Palkia version with Outrage or Thunder can deal with Kyogre because of its 4x resistance to Water-type moves. Likewise, Latias with Soul Dew and Grass Knot or Recover can deal with Kyogre by switching in and dealing heavy damage (or Recovering).

Gengar has extremely poor defenses, especially by Ubers standards, so it will need a lot of defensive support. Gengar has weaknesses to Dark-, Ghost-, and Psychic-type moves, but many other types of attacks will be used on it as well (since it really can’t take any attack). It is important that you have Pokémon who have resistances or can take attacks, as Gengar will add no defensive aspects to your team. Since Gengar will be primarily used on offensive teams, Pokémon like Dialga, Palkia, Scizor, and Groudon can all provide for a strong defensive core, while also maintaining a threatening offensive presence. Pursuit users, such as Scizor, Metagross, and Tyranitar, can kill Gengar before you have the chance to switch out to a suitable counter, so it is important that you find a way to eliminate them first. Scizor can be dealt with by a Mewtwo who has a Fire-type move. Scizor will normally switch in on it to Pursuit or U-turn it, only to be met with an OHKO. If your Gengar has the ability to switch moves, it can use Hidden Power Fire; however, this is risky, as you will have to predict well, or else Gengar will be taken out by Bullet Punch. In this case, it is best to have a Groudon and also a check to Kyogre, since when Kyogre switches in it brings the rain, which causes Scizor not to be OHKOed. Metagross is tricky, as Gengar itself cannot reliably take it out, even when it has a Life Orb. A luring Mewtwo can work similarly with Metagross as well, however, Dialga and Palkia are also potential helpers, as they resist Bullet Punch, can outspeed Metagross, and OHKO it with Fire Blast. Finally, there’s Tyranitar, who can be handled by Kyogre, who can come in with its bulk, change the weather, and take out Tyranitar with Surf. If Gengar can switch moves, then a well-placed Focus Blast can take it out. Calm Mind Rest + Sleep Talk versions of Kyogre can also handle all three of these threats (unless Metagross uses Explosion).

The Pokémon who are most commonly paired with Tyranitar, Metagross, and Scizor are Garchomp, Lugia, Dialga, Kyogre, Palkia, and Darkrai. Lugia can completely stop Garchomp in its tracks by using Reflect and Ice Beam; it is also immune to one of Garchomp’s STAB attacks. Jirachi can also use Body Slam to paralyze Garchomp, which totally destroys its usefulness, especially when it’s a Choice Scarf user. Lugia can be tormented by Wobbuffet, who will trap it with Shadow Tag and then proceed to Mirror Coat it to death, or use it to set up a sweeper. Whirlwind won’t even work, as its negative priority will allow Wobbuffet to Encore its last-used move. Dialga can be revenge killed with Wobbuffet via Mirror Coat as well, however Choice Specs sets would have to be handled by either a special wall, or a bulky Steel-type, such as Jirachi or Scizor. Kyogre is a fearsome monster, and the only two Pokémon who can reliable check it are Palkia and Latias. They can both switch into even a full-power Water Spout, and then attack Kyogre to weaken the Base Power of the move (Latias can also Recover). There is no true counter to Palkia, and it must either be revenge killed, or taken on a set-by-set basis; the most common set, the Choice Scarf, can be revenge killed by Wobbuffet. Finally, Darkrai can be dealt with by Scizor, who can use U-turn or Superpower, or Bullet Punch if Darkrai is weakened. However, Scizor can only truly counter Darkrai if Sleep Clause is activated, and even then it must be wary of a +2 Focus Blast.

Other Options

OU

Sludge Bomb was left out of the main sets, as it offers rather poor type coverage despite being Gengar’s most powerful attack. Most Grass-types won't enjoy a hit from Shadow Ball (especially Celebi), and are unlikely to stay in on Gengar, as Gengar resists their main STAB attacks.

Gengar has Energy Ball and Giga Drain to hammer Swampert and Rhyperior, if either is a problem for your team. Psychic hurts Fighters more than Gengar's other attacks, but most of them won't enjoy boosted Shadow Balls, so it still remains a lesser option.

Mean Look can trap an opponent so you can Explode on them and Perish Song can phaze opponents. Mismagius is better than Gengar in this respect due to Mismagius' higher Special Defense, but Gengar can employ Hypnosis (and it also has more Speed than Mismagius). Taunt can prevent Blissey from firing off Thunder Wave and Toxic, allowing you to switch in your physical attackers without fearing status. Will-O-Wisp can hit Tyranitar and Scizor hoping to switch in; however, it is an option better left to any of the Rotom Appliances. Destiny Bond works well in place of Explosion if you are sure that Gengar will be KOed with the following attack.

Because of Gengar's plethora of attacks, Expert Belt is a fine option. It allows Gengar to hit harder, but without the 10% recoil that Life Orb inflicts. If you're playing under item clause, you can use Black Sludge over Leftovers.

Ubers

Thunder or Energy Ball can be used to hit Kyogre and/or Groudon harder. However, Latias or Palkia can generally deal with Kyogre and Groudon better, although it still can be handy if your team does not have one of these two. Explosion is another possibility on the Choice Scarf set, as it provides a fast way to almost instantly take out a Pokémon (remember to use a Hasty nature in this case). Destiny Bond is a possibility, as it can prevent some Pokémon from KOing you, or else they will die too. By strategically using Destiny Bond, you can eliminate more counters to your other Pokémon, as well as threaten any would-be counters to Gengar. The drawback to this, however, is obviously that it involves Gengar dying in the process. Finally, Substitute is a possibility on the Life Orb set. Substitute aids in prediction, like Protect, however it allows you to take out Pokémon, such as Scizor, who would otherwise destroy you with priority moves. The only drawback of this is that Gengar will be losing a lot of health from Substitute + Life Orb recoil alone.

A Choice Specs set is also possible, as Gengar has very good Special Attack and Speed stats. However, Gengar loses its ability to revenge kill as effectively (which is really its niche), and the role of Choice Specs user is better filled by by Mewtwo, Kyogre, Palkia, or Dialga.

EVs

OU

341 Speed (216 EVs) outruns max Speed Adamant Dugtrio and Timid Mismagius. 347 beats max Speed Infernape, while maximizing your Speed gives you the chance to win the coin flip against opposing Gengar. 204 Speed EVs is a good point to aim for on Choice Scarf sets so Gengar will outrun Adamant +1 Dragon Danced Salamence and positive natured Choice Scarfed base 90 Speed Pokémon, though max Speed is generally preferable to tie with other Choice Scarf Gengar. A Timid nature allows you to outspeed up to positive-natured base 105 Speed Pokémon. You can, however, opt to use a Hasty or Naive nature if you want to use Explosion.

An Attack stat of 200 (Hasty or Naive nature, 136 EVs) is required to guarantee an OHKO on 252 HP / 252 Defense Bold Blissey with a Life Orb Explosion.

Gengar can invest 72 EVs in Defense allowing it to always survive CB Scizor Bullet Punch assuming it has not taken any prior damage.

Ubers

Gengar’s Special Attack and Speed EVs should always be maximized so it can hit hard and fast. Its defenses are sub par (especially by Ubers standards), so it will be unable to take any hits anyway.

Opinion

OU

Gengar is one of the most unpredictable Pokémon you will encounter. It has an excellent movepool backed up with great Speed and impressive Special Attack. Although Gengar's defenses are awful, its immunity to the popular Ground- and Fighting-type attacks (and Normal-type ones too) allows it plenty of opportunities to switch in and wreak havoc.

Ubers

Although Gengar is normally thought of as an “OU only” Pokémon, it actually has an important niche in the Ubers Metagame: revenge killing. While Gengar has terrible defenses, it has extremely useful immunities to Fighting-, Normal-, and Ground-type moves. These, plus its high Special Attack and Speed stats, and its great movepool, make it a great revenge killer who can check a large portion of the metagame’s ferocious sweepers.

Counters

OU

Anything with Pursuit will really ruin Gengar, especially Choiced variants, although Weavile and Tyranitar fear Focus Blast and Metagross won't enjoy a burn or repeated hits from Shadow Ball / Focus Blast (which can 2HKO with Choice Specs). If Tyranitar has 252 HP / 216 Special Defense and a Careful nature it will always survive Timid Gengar's Life Orb Focus Blast. If it has 252 HP / 128 Special Defense, it will survive Modest Choice Scarf Gengar all the time. Beware of Choice Scarf Heracross' Pursuit too. Spiritomb has both Pursuit and Sucker Punch and plenty of Special Defense to absorb Gengar's attacks. Be wary of Sucker Punch and / or Pursuit from various other less common opponents as well, like Absol, Drapion, Dugtrio, and Toxicroak.

Scizor also makes an excellent counter to Gengar as it resists Shadow Ball. Once in, Scizor can either use Bullet Punch if Gengar stays in, or Pursuit a fleeing one.

Blissey does well against most sets; she can paralyze Gengar with Thunder Wave or wear it down with whichever special attack (Ice Beam, Flamethrower, Thunderbolt) she happens to carry. Blissey can be easily shut down by Tricking a Choice item onto her, though. Snorlax with Crunch does a fine job, especially Sleep Talk versions as they can absorb Hypnosis. Snorlax can also put the hurt on Gengar by packing Pursuit. Beware of Focus Punch, Focus Blast, and Explosion though. Jirachi and Bronzong both do well with their high Special Defense and neutrality to most of Gengar's attacks. Heatran (especially Choice Scarf versions) can switch into everything barring a Fighting-type attack, and gets a boost from Hidden Power Fire. Even without a boost, Fire Blast will OHKO standard Gengar 100% of the time when accounting for Stealth Rock damage.

Gengar's attacking power and incredible movepool mean that countering it is a rather daunting prospect. Thankfully, Gengar is incredibly fragile and most neutral attacks will at least score a 2HKO.

Ubers

Pursuit users give Gengar a lot of problems, especially Choice Scarf users, as they can OHKO Gengar even if it doesn’t switch out. The common Pursuit users in Ubers are Tyranitar, Scizor, and Metagross. Of these, Metagross is probably the most threatening, as it has a humongous Attack stat, and it is also extremely bulky.

Steel-types are also problematic, as they resist a good portion of Gengar’s moves, especially its most common one, Shadow Ball. Metagross and Scizor come up again, as they are also able of using Pursuit. Jirachi (and Metagross) is also worth mentioning, as, while it does not resist Shadow Ball, it still resists Hidden Power Ice, and it is neutral to Focus Blast. Jirachi also has great bulk with its 100 / 100 / 100 base defenses, and it also generally carries status moves, such as Thunder Wave, which will leave Gengar totally useless.

Kyogre can be a problem for Gengar, since it actually has base HP and Special Defense stats that are quite large. Without Explosion or Thunder, Gengar will not be able to do with a Kyogre who has Calm Mind + Rest / Sleep Talk. In return, Kyogre can alternate between Calm Minding and Resting (and using Sleep Talk) until it gets the boosts it needs. Then, it can sweep your team with Surf. In a similar manner to Kyogre, Ho-oh will take little damage from Gengar that lack Thunder or Explosion, and then OHKO Gengar with Brave Bird or Sacred Fire. Furthermore, Pokémon who are faster than Gengar will generally force Gengar to switch out, because of its terrible defensive stats.

Finally, Blissey will pose a large problem for Gengar, unless it carries Explosion. Blissey is immune to Gengar’s STAB Shadow Ball, and it also takes pitiful damage from its other moves. Also, even when Gengar uses Explosion, it can be predicted with a switch to a Ghost-type. This will cause Gengar to basically kill itself while doing absolutely no damage.