Mother Gengar was a popular competitive deck archetype in Pokémon Trading Card GamePlay! Pokémon in the late 2008-2009 season as well as through much of the 2009-2010 season. The deck placed well at many large tournaments. The deck's name is derived from the combination of Nidoqueen's Poké-Body, Maternal Comfort, and Gengar, on which the deck's strategy is based.
The synergy of Gengar and Nidoqueen stems from Gengar's Fainting SpellPoké-Power, which provides a 50% chance to knock out the opponent's Pokémon if Gengar is knocked out by an attack. After straight Gengar began to see play, more players began to use strategies such as Uxie's Psychic Restore attack and Crobat G's Flash Bite Poké-Power to circumvent Fainting Spell. Most of these tactics had a low damage output, and required Gengar to have relatively low remaining HP. Nidoqueen's Maternal Comfort removes damage from Gengar between turns, making it more difficult for players to knock out Gengar with a low damage output, and as a result increasing the chance of Fainting Spell coming into effect.
Although Nidoqueen is primarily used for Maternal Comfort, it can also provide a decent attacker in a pinch, hitting 40 for just with Mega Punch and significantly more, depending on the size of the opponent's bench with Ruthless Tail, for . However, the deck's primary attacker is Gengar. Gengar's strength was in its ability as a sniper, targeting the opponent's benched Pokémon with Shadow Room. In combination with Crobat G's Flash Bite, one Shadow Room could take easy knockouts on the opponent's benched Uxie and Azelf for just . Additionally, Shadow Room knocked out other common plays at the time such as Unown Q and Unown G, which made taking six prizes with the deck exceptionally easy.
Gengar - The deck's main attacker, Gengar is used primarily to snipe around the opponent's weak benched Pokémon for cheap, easy prizes. However, Gengar is able to knock out the opponent's Active Pokémon, either through a lucky Fainting Spell flip or with the situational but powerful Poltergeist attack.
Nidoqueen - Nidoqueen, while it can provide attacking support, is primarily used for healing Gengar to prevent the opponent from circumventing Fainting Spell.
Claydol - Claydol is the deck's main draw support. With its Cosmic Power Poké-Power, Claydol allows for continual hand refreshment which is critical to recovering lost Gengar.
Uxie - Although Claydol provides a more consistently reliable source of draw, a Uxie Set Up early in the game can be critical to getting off the ground after a bad start or drawing the combination of cards needed to get a Claydol on the field.
Crobat G - Crobat G's Flash Bite Poké-Power, in combination with Poké Turn, is vital to knocking out the opponent's 70 HP benched Pokémon, such as Uxie and Azelf, with just one Shadow Room.
Looker's Investigation - Looker's Investigation helps the Mother Gengar player gauge whether Shadow Room or Poltergeist will be more effective in certain situations by showing how many Trainer, Supporter, and Stadium card the opponent has in his or her hand. It can also provide hand refreshment in a pinch.
Night Maintenance- With only 110 HP, multiple Gengar will often be knocked out in a single game, and Night Maintenance's role is to return them to the field as soon as possible.
Rare Candy - Rare Candy simply allows the Gengar player to skip the Haunter or, in the case of Nidoqueen, Nidorina phase of evolution, which allows for an early advantage due to a faster setup.
Call Energy - Call Energy can salvage an otherwise bad start, or simply add to an already good one. Early in the game, attacking is not especially important to begin with, and taking two Basics out the deck can result in a much faster setup. Putting the Basics on the bench rather than into the hand, as many supporting effects do, means that they can be evolved on the player's next turn. This can often lead to a turn two Claydol, and from there, the Mother Gengar player's setup is generally simple.
The deck list appearing below is not official; it is meant to represent an average build of the archetype, not specifically constructed for any regional metagame. Being that this is merely an archetype, a player may wish to change any part of this deck when building his or her own version.
The following cards are often used in Mother Gengar in place of certain cards included in the above list.
Mewtwo LV.X- Mewtwo LV.X provides a way to easily beat decks based on Pokémon SP. Its Poké-Body, Psybarrier prevents it from being damaged by Basic Pokémon.
Azelf - Azelf's Time Walk Poké-Power can be used in the event that an important Pokémon card(s) is prized. In most Mother Gengar builds, Azelf is not necessary because the deck runs multiple copies of important cards.
Cyrus's Conspiracy - Cyrus's Conspiracy is occasionally used as a component of the deck's engine. Although Mother Gengar only runs two Team Galactic's Invention Trainer cards, both of them Poké Turns, Cyrus's Conspiracy's ability to search out a Supporter card from the deck, as well as a Basic Energy, can be beneficial.