FLGS - Friendly Local Game Shop, the place where you spend your money on the entertainment below. Sometimes the "Friendly" is replaced with another word that starts with the letter F depending on the quality (or lack thereof) of the venue in question.
3.75, 3.PF - Pathfinder, the most popular and enduring of all attempts to keep the 3.5 rules set alive, currently the world's best-selling roleplaying game (although ICV 2 3rd quarter numbers, which would reflect Gen Con and the release of D&D 5th Edition, aren't in yet).
Big El - Elminster, the most famous and almost most powerful wizard in the Forgotten Realms.
Loli-Pope - In Eberron, Jaela Daran, the current leader of the Church of the Silver Flame, happens to be a little girl. Also Sailor Pope, for hopefully obvious reasons...
In the same setting, the NPC known as the Lord of Blades (LoB) is often referred to as the LoBster.
Big T - The Tarrasque, one of the strongest monsters that is included in most editions of D&D. Often a standard to compare a character's battle prowess is beating Big T (though not killing it, because that requires a caster with wish or miracle to finish off once it's down).
Purple People Eater: The Purple Worm. Named as such because in almost every edition, it is used to showcase the "swallow whole" monster ability.
Creating a new character is nicknamed 'rerolling', since to make it, you have to roll more dice. This has carried over into MMOs.
CoDzilla - A (3.X edition) Cleric or Druid, so named for their incredible power in the hands of a competent player.
Not to be confused with the alternate term for CoD, which stands for a Circle Of Death monster, a large monster who can unleash devastating full-round attacks on a party member if they don't have to move - which typically means the melee classes.
Pun-Pun - A character who uses the Sarrukh's Manipulate Form ability to give themselves any ability they want. Any. From a famous message-board post with a Kobold named Pun-Pun using this ability to demonstrate exactly how silly it could get, and in Pun-Pun's case that's the single silliest Game Breaker yet known.
Mr. Shouty Man - RPGNet term for D&D 4E's Warlord.
Lazy Lord: a Warlord who eschews ever making any actual attacks for him/herself, instead every action is granted to OTHER players. and staying out of direct combat.
Complete Crud: Complete Psionics. Infamous for its low quality: plotholes note Characters with Illithid Heritage feats are the descendants of mind flayers, despite the species reproducing parasitically. Fans have created a variant where they are the ancestors of the mind flayers, but this was only a fan creation and clearly not the original intent., nerfing things that were perfectly balanced or underpowered to begin with note You are only allowed to have one astral construct at a time because... uh... and introducing classes which were broken in both definitions of the word note Divine minds are unplayable as written, and erudites are broken once abilities added to it by web supplement are added, with even normal erudites being crazy-powerful and oddly-written.. The only things fans consistently enjoy about the book are A. free as an excerpt (Soulbow), B. a variant of a feat in a better book (Practiced Manifester is Practiced Spellcaster, except psionic) and C. the Ardent.
Happy Stick: A Wand of Cure Light Wounds, considered perhaps the most indispensable magic item for a low-level party.
Greyhawk (verb): To loot. Example: "After we kill the orcs, we Greyhawk their bodies."
Laser Cleric: Nickname for 4E clerics that focus on dealing ranged Radiant (i.e. light, holy) damage rather than typicalclerical duties.
Lizards on the Toast,Wizzing on a Post, etc.: Derogatory nicknames for Wizards of the Coast, D&D's current publisher.
Wiz Bro: Often used when Wizards of the Coast is making something perceived as a Bad Move, used to imply that said move is being forced from Wot C's corporate parent, Hasbro, rather than originating from inside.
Abuse Magic Device: The "Use Magic Device" skill.
Necklace of Suicide: A Necklace of Fireballs, since certain circumstances can cause all the beads to be set off on the wearer.
BECMI: Basic/Expert/Companion/Masters/Immortals, the rules sets for the pre-3e D&D (as opposed to AD&D) game.
MaRo - Mark Rosewater, Head Designer. Came from the card Maro, which was accidentally named when a file was sent to the Creative department with the abbreviation of his name listed as the creator of the card; Creative figured that it was a made-up fantasy name, and used it.
Trollshroud: A variant of the "Shroud" mechanic (which makes a permanent untargetable by spells or abilities) that only prevents opponents from targeting the permanent with trollshroud. Named after Troll Ascetic.
Notably, the 2012 Core Set is giving trollshroud an official keyword, "hexproof".
Fat Pants - Hero's Resolve. It greatly boosts a monster's toughness, and monsters with high power and toughness are often known as "fatties", while creature enchantments in general are often known as "pants". (Plus the character depicted, Gerrard Capashen, looks fat in those pants.)
Goyf or Goofy - Tarmogoyf, widely considered to be the best pure beatstick of all time.
Sex Monkey - Uktabi Orangutan, which is infamous for featuring, in addition to the orangutan, two monkeys that appear to be... copulating.
The Stick - Isochron Scepter, which allows you to take a cheap spell and copy it every turn. Any card used with the Isochron Scepter in this manner was said to be "on a Stick".
Predating Isochron, "X-on-a-stick" is a nickname for a non-creature permanent that has the effects of an established spell as an activated or triggered ability: Seal of Fire is Shock-on-a-stick. "X-on-legs" is a similar nickname for creatures with abilities that evoke spells, or "X-on-wings" if the creature has flying: Nekrataal is Terror-on-legs.
As a companion to "Tim," Samite Healer, which prevents 1 damage by tapping, is sometimes known as "Al."
Tom - The extremely creative Prodigal Pyromancer, which is effectively Tim, but red instead of blue (which, arguably, the card should have been from the beginning). Similarly, any old card reprinted in the "right" color, such as the newer red Enrage vs. the old black Howl From Beyond. Also known as "Comrade Tim" or "Communist Tim", building on the Incredibly Lame Pun of it being a red creature.
Sonic Boom - Not quite a card name, but a maneuver; using Guile's special ability (which allows you to play yourself a spell you counter) to throw a direct damage spell back at your opponent. Named after the signature move of Guile from Street Fighter.
Each winner of the annual Magic Invitational gets to design a card that will appear in a future Magic set. The cards thus produced generally have art featuring a likeness of that player, and are nicknamed after them, if they get popular enough to earn a nickname. For example, Bob (Bob Maher) for Dark Confidant, Finkel (Jon Finkel) for Shadowmage Infiltrator, and Kai (Kai Budde) for Voidmage Prodigy. Solemn Simulacrum is sometimes known as Jens (after Jens Thorens), but is more commonly known as "Sad Robot".
Dark Confidant was reprinted In Modern Masters, causing many people to refer to the new one as Skrillex.
And, of course, there's Superman - Morphling to anyone who has yet to learn exactly how absurd the infamous Game Breaker can be.
Pemmin's Aura, a card that gives a creature all the abilities of Morphling, is an intentional anagram of "I Am Superman."
Torchling am not sometimes known as "Bizarro", not due to it not being a slightly stronger version of Morphling of the same color.
Painlands - A cycle of nonbasic lands that can be tapped for colorless mana, or for one of two types of colored mana at the cost of dealing a point of damage to you. There are two subcycles: the Allied Painlands which first appeared in Ice Age, and the Enemy Painlands which first appeared in Apocalypse.
Man Lands - A collective nickname for any land that can turn into a creature, such as Faerie Conclave.
Weenie Madness: a particular deckbuilding style, wherein a player will load his deck down with inconsequential, very weak creatures, and mana-regenerators. Lots of them. The power of a 'Weenie Madness' deck lies in the sheer number of expendable creatures: while more powerful creatures take a larger amount of mana to summon, and thus are less common, Weenie Madness-appropriate creatures are weak enough that they are plentiful in any M:tG deck. Thus, while the other player expends Mana on a few select 'power creatures', the Weenie Madness deck can just keep going, overwhelming its opponent by sheer force of numbers.
Tutor: Any card or ability that allows you to search your deck for a particular card or card type and improve your access to it (i.e. putting it into your hand or on top of your library). Named for Demonic Tutor, the first such card, and a number of cards which are similar in both name and effect, such as Worldly Tutor and Enlightened Tutor.
Combo Winter: Winter 1998, after the release of the Urza's Saga set, during which the Metagame was dominated by a large number of high-powered combo decks that were often capable of winning on the first or second turn.
There are a number of decks named, bizarrely, after breakfast cereals.
Fruity Pebbles is a deck running the combo of Enduring Renewal, Goblin Bombardment, and a free creature like Shield Sphere to deal infinite damage. According to urban legend, someone said "You have to be Fruity Pebbles to play this deck" and the name stuck, though more likely it refers to the colors of the cards and the fact that Bombardment only deals one point of damage at a time ("firing pebbles", as it were).
Second Breakfast, named for the key card Second Sunrise and revolved around using lands and artifacts that sacrificed themselves for effects that helped draw cards, recover cards — like the Sunrise — from the graveyard, generate mana, and all sorts of other bonuses. The deck won by setting things up so that a single play of Sunrise could return a Sunrise to the hand, return an artifact to play that sacrificed itself to deal damage and net the mana to pay for both. That, or just using the massive number of spells cast that turn to Grapeshot someone for massive damage.
Chimney Pimp or simply the Pimp for Chimney Imp. (Related to a Forced Meme declaring it to be the best card in the game.)
Walletslayer Angel - Baneslayer Angel, one of the best creatures in the game at the moment, formerly worth $40-50 each and still fairly expensive. Sometimes Bankslayer instead.
Similarly, Jace the Wallet Sculptor for Jace, the Mind Sculptor, which was worth around $100 for a time up until it was banned from the Standard format. (Also known as Jace, the Mind-Raper; Jace, the Metagame Sculptor; or Jace, the Gamewinner.)
And as of Spring 2013, even though he's only legal in two formats, he went upto $150.
The current planeswalkers are collectively known as "Neowalkers", "Bradywalkers" or "The Brady Bunch", after Brady Dommermuth. (They have a lot of other nicknames, but "Neowalkers" and "Bradywalkers" are the most printable.)
Decks which focus on summoning various different Planeswalkers into play are called "Super Friends decks".
Yawgmoth is also called Yawgie or Ol' Yawgie in forums.
The current factions of Phyrexia are known as [Colour]rexians depending on the colour of mana they require. "Whiterexia" seems to be the most popular.
A derogatory term used by fans of older Phyrexia who dislike the newer incarnation is Faux-rexia.
Dracula-penis - what quite a few fans have already taken to calling Olivia Voldaren, due to a very unfortunate last-minute change in her art which makes her look... extremely well-endowed and entirely too happy to see you.
Bounce off: To end a run by hitting a piece of ICE that otherwise does no harm.
Corp: The corporation.
Corp Score: The corporation card Accounts Receivable, because it functions identically to the Runner card Score!: pay 5 bits, gain 9 bits. (In Android: Netrunner, the cards are Sure Gamble and Hedge Fund.)
Crash: Draw two cards with "Crash Everett, Inventive Fixer".
Escape/ESC: Emergency Self-Construct, used to escape death through flatlining.
Neal: The runner card Fall Guy. Taken from its flavor text: "What I like best about you, Neal, is that you trust me.". Also the online name of a prominent Net Runner player and fan, who wrote a Net Runner newsletter called "Neal's Last Words".
Pump the Broker/Dump the Broker: Spending an action to add or remove bits from the Broker. Named after the form of stock fraud known as "Pump and Dump".
Smith's: To use Smith's Pawnshop to trash a card for a bit.
Timetwister: MIT West Tier, named as an anagram of the Magic card Timetwister which has a similar function.
Working at McDonalds: Gaining a bit (the currency of the game) by spending an action, rather than through some faster means. Similarly, "working a double/triple/quadruple shift at McDonalds": spending two, three, or four actions in a turn simply to gain as many bits.
Hamsterwheels - Doomwheels, which are pretty much gigantic armed hamster wheels
Tapdance of Gork - Gork's Warpath, an orc spell that summons an ectoplasmic effigy of Gork to stomp everyone at random. Spawned due to the White Dwarf article that said this was the original working title of the spell.
'Nids has actually become so widespread that its been adopted as an in-universe nickname, particularly in the Ciaphas Cain books.
Failaddon / Failbaddon - Abaddon the Despoiler, thanks to losing all 13 Black Crusades and never making it past Cadia despite having an army of Space Marines, Daemons and Cults vastly outnumbering the Imperial Forces.
Flying Circus: Any 6th edition army, particularly Necrons and Imperial Guard, built around using as many Flyers as possible.
Cap'n Gabe - Blood Ravens Brother Captain (later Chapter Master) Gabriel Angelos.
Space Marines, particularly the first edition models, are occasionally referred to as "Beakie Boyz" or "Beakies" due to the distinctive pointed "snout" of the Mk VI Corvus Armour's helmet (itself inspired by the medieval bascinet). Though few Space Marine models use the older helmet, the Orks still use "Beakie" as shorthand for Space Marine, and a certain image board asserts that the earlier Space Marines were much more macho and badass than the Nancy-boys in skull-faced helmets that run around today.
Many Orkish nicknames are popular among players as shorthand for various races and wargear: "Panzees" = Eldar; "Beakies" = Marines; "Umies" = Imperial Guard, regular humans; "Dakka" = guns, cannons; "Choppa" = close combat weapons; "Stunties" = Squats; "Fishies" = Tau
Life Support Toilet - the Emperor's Golden Throne, for the function it serves and the unfortunate implications of the word "throne."
Also known as the Golden Toilet or Golden Shithouse, for the same reasons mentioned above.
Musical Wounds - the tactic of exploiting 5th edition wound allocation rules for units of differently-equipped multi-wound models, to spread the wounds evenly on them rather than let models die.
Greenwing - regular Dark Angels soldiers, as opposed to the more elite black-armored Ravenwing and white-armored Deathwing.
Fishmalk - A derisive nickname for those who played a certain type of Malkavian in Vampire: The Masquerade. The curse of the Malkavians is that they all become insane upon Embrace, so some players use it as an excuse to play a "wacky," "unpredictable" character who basically pranks the hell out of others. Named for how these Malks are likely to slap you in the face with a fish (or otherwise do something silly involving fish or the word "fish.")
There's also the joke: "How many surrealists does it take to screw in a light bulb?" "FISH!" The original meaning of the term stems from a very early LARP game involving a number of Malks and a prank involving fish. More specifically, a bomb that flung fish across an entire room.
Rite of Pants - The Rite of Talisman Dedication in Werewolf: The Apocalypse, which allows werewolves to attune certain items so they change when the werewolf changes form. So named because it's most commonly used with clothing.
The Lodge of Batman, a.k.a., The Lodge of the Goddamn Batman - A fast-spreading nickname for the Lodge of Spires in Werewolf: The Forsaken, a sub-group of the Iron Masters dedicated to being the perfect urban predator — that is, mastering the geography of the city like your standard werewolf would master the forest.
Soul Pretzel - Legacies from Mage: The Awakening, so named because creating a Legacy involves reshaping your soul to incorporate elements of the Supernal.
The name of the Deathlord First And Forsaken Lion is often abbreviated as FaFL, pronounced "Falafel".
Or "Victor von Deathlord" (or, sometimes, Darth Vader).
The head of the Sidereal Bronze Faction, one of the most badass Supernatural Martial Arts in existence and a first-rate Manipulative Bastard is named Chejop Kejak... but better known to the fans as Ketchup Carjack, Kneecap Carjack, Sean Connery, or HULK HOGAN.
The Primordial named Autochthon is also known as Autobot. Also Auto-kun.
Gazellecarp — The capstone charm of the Dreaming Pearl Courtesan Style transforms your character into a serpentine chimera whose features include a head like a gazelle foal and multiple carp fins down the sides.
Her Redness, Akumacakes — The Scarlet Empress. The former is actually used in the material.
Tepet Fuck-Off — Tepet Fokuf, the Regent of the Realm. So named because, well... he's a total fuck-off. The man is totally incompetent, and was chosen just so he can rubber-stamp bills for anything the Realm needs done... and because he frequently pleasures himself to passages from the Immaculate Texts. Yeah.
Captain Shoulderpads — Dace, because of his outfit.
Harmonious Booty — Harmonious Jade. Less because of the actual size of her booty and more that she looks and sorta acts like a Sassy Black Woman.
It may also be the fact that she went from wearing loose pants in the first parts of the game to the loincloth thing she has now. Her fanservice factor got kinda ramped-up over time.
DEMETHEMANIA — Demetheus, a big, burly Dawn Caste. In some of the setting fluff, he wrestled giant lions with his bare hands and won; thus a Memetic Badass was born.
It really didn't help that his artwork was visibly inspired by The Rock.
Ma-Ha Bishi — In reference to Ma-Ha Suchi's highly Bishounen First Age appearance, complete with roses. Also known as Ma-Ha Suave.
The Cosmic XBOX — The Games of Divinity that the gods spend most of their time playing.
Also known as the Pantheon Playstation, The Glorious Golden Gameboy, and the Wondrous World of Warcraft. And "Celestial Crack," sometimes.
Princess Starscream — the deathlord Princess Magnificent, forced by the Neverborn to work for the First and Forsaken Lion, and not at all happy about it. As a logical progression of this, another nickname for the Lion is "First and Forsaken Megatron."
Despite this, they are sometimes depicted as tsundere for each other, just for the lulz.
Princess Birdhat, due to how she dresses in all of her illustrations.
The Yozi (Demon Prince) She Who Lives In Her Name, an utterly alien being consisting of spheres orbiting around spheres orbiting around a fire, is sometimes called "Swillin'", from the acronym "SWLIHN".
Also a rather less pleasant explative by the freelancers due to the sheer wordcount "She Who Lives in Her Name" eats.
Likewise, Yozis Adjoran and Isidoros are sometimes called Adoorjam and Isadoor, and the Ebon Dragon is shortened to "Ebby".
"The Book of Three Circles, Two Breasts, and One Giant Cameltoe," a reference to the earlier paperback supplement on sorcery, The Book of 3 Circles.
The Deathlord Mask of Winters is sometimes known as the Mask of Illiteracy, after stats were published that gave him a Lore score of 0, which means he can't read.
The originally-unnamed combat-twink Primordial from the Aftershock War was known as Chungira, after Jon Chung, a combat optimiser par excellence on the rpg.net forums. Its eventual canon name was Ramethus.
Disco Ninja Style, for the martial art Crystal Chameleon Style, which focuses on speed and stealth through bright psychadelic lights.
Some of the writers have their own nicknames - Michael Goodwin is generally known as Neph (short for his handle on forums, Nephilpal), while Holden Shearer is known as the Hamster due to his tendency to use hamster-based avatars.
The Lunar in Masters of Jade, for her cake-eating shenanigans, is known as Chompy.
Chaos: Used to describe any monster that can only be summoned by removing certain monsters in your grave from play, and contain either a once-per-turn card removal or full-field-nuke effect. Named after the Envoy cards who started the trend, Chaos Emperor Dragon - Envoy of the End, and Chaos Soldier (Black Luster Soldier in English) - Envoy of the Beginning, both of which came out in the card set Invasion of Chaos.
Contact Fusion - Canonically used to describe the summoning requirement of the Elemental Hero Neos fusions, also used by the fandom to describe the similar method of summoning the V-Z and Gladiator Beast fusions.
Gogiga Gagagigo, while not widely used, was known by most that knew of it as G7. The slightly better but smaller Giga Gagagigo was G6.
Lucksworns: A derogatory name for Lightsworns due to their inconsistent tournament record.
Omni-Heroes: The name given for 6 Elemental HERO Fusions whose Fusion Materials are 1 Elemental HERO (or, in Absolute Zero's case, any HERO) plus 1 monster from 1 of the 6 Attributes.
Trample: Stolen from the MtG game, used to describe an effect that allows a monster to inflict battle damage to the opponent when attacking a defense-position monster, providing its ATK is higher than the other monster's DEF. Officially referred to as "Piercing", a term which was briefly used in reprints of some old cards, but quickly abandoned.
Tag Out: The universally agreed upon term for using the effects of the Gladiator Beasts.
Tinzo: A Jinzo that was the promo card that came with a tin, rather than the harder-to-get secret rare version from the actual set.
Tutor/Recruiter: The various monsters in the game with effects that can search for other monsters in your deck (putting them either on the field or in your hand).
Twilight: A deck that uses both Lightsworns for their milling effects and Zombies for their ability to swarm cards from the graveyard.
The Pornomancer: A character design made possible with the latest edition got this nickname. Said design basically amounts to stuffing as many dice into seduction as possible. The joke is that he (it's usually portrayed as a man for added hilarity) can seduce anyone into doing anything.
The Unseen: The classic designs for several BattleMechs that were licensed from several anime series, most notably Super Dimension Fortress Macross and Dougram. A lawsuit from Harmony Gold (of Robotech fame) indirectly forced FASA to stop using the designs note It's complicated, but Word of God is that the artwork was ditched unilaterally by FASA, the inference being that they had limited rights to use the Dougram and Crusher Joe designs, but that the lawsuit had made FASA paranoid about further lawsuits, retiring any art that did not originate at FASA itself. This had the odd result of forcing FASA to retire the bulk of the IIC 'mechs, originally created by Studio Nue — the original creators of Macross! — for use in a Japanese release of the game to replace the original designs that, for obvious reasons, were not appropriate to use., and the 'Mechs in question were quietly Put on a Bus in favor of original designs. As of June, 2009, Catalyst, the current rightsholder somehow was able to renegotiate for rights to use the Dougram designs, making them "Reseen".
The lawsuit in question was very complicated and had no clear winners, the result being that there is no company in North America with the clear rights to distribute any derivative works based on Macross.
The Reseen: The game supplement Technical Readout: Project Phoenix included legally-friendly new designs for the Unseen that allowed them to re-enter circulation. Unfortunately, the developers of the latest MechWarrior game seem to have forgotten this....
Alpha-Strike: Firing all of a 'Mech's weapons at once.
Alpha-baby, Refrigerator: A 'Mech design capable of alpha-striking constantly without overheating.
"Boat mech": A 'Mech design based on loading up on as many of a single weapon type as possible. One of the most common variants is putting nothing ER Large Lasers and heat sinks in a Mad Cat, referred to as a 'laser boat', or the Archer as a 'Missile Boat'
Meatcannon — the AC/20, so named for ripping huge chunks out of a Mech like a predator ripping meat off its prey.
Ptoo or Ptwo — on the opposite scale, the spitball-like damage of the AC/2
Criticator, Critseeker — any weapon system more likely to generate critical hits rather than punch through armor, like LBX Autocannon and massed missile banks.
Headchopper or Headcapper — a weapon strong enough to one-shot a Mech's cockpit (such as Gauss rifles), thus instantly removing it from play.
Several individual BattleMechs have fan nicknames:
Crud — The Crusader model of Battlemech, both for its CRD serial number and the placing of ammo in the center torso where it was more likely to explode. Worse, the original CRD-3R would explode on any critical hit to its left or right side torso locations as well unless the ammo stored there was already used up thanks to said ammo bins being the only items in those locations that could be critically hit — and critical hits to 'empty' slots are re-rolled — thus making all three torsos filled with explodable ammo.
Warhampster, 'Slammer, Whammy: the Warhammer
Eggs, Eggheads: mechs with an egg-shaped body, like the Catapult, Stalker, Marauder, and Mad Cat
Low-Cost: the Locust, as a pun on it being the least expensive mech at 1.2 million C-Bills.
Bug-Mechs: The Wasp, Locust and Stinger, both for their insect names and their tendancy to be easily squashed.
Salad-shooter: The Saladin, a hovercraft armed with a massive AC/20
Sally: the Salamander, an assault missile boat. Also the Salamander Battlearmour
Urbie, The Walking Trash Can: the UrbanMech
Gauss Rifle on Legs: the Hollander
Trenchbucket: The Trebuchet
Timby: The Timber Wolf/Mad Cat
Gausszilla: Any mech carrying two (or more!) Gauss Rifles.
Worthless, Whitworthless, Shitworth: The Whitworth
B-Mer, B-Master: The Battlemaster
Fatlas: The Atlas
Forceful Sodomy Mech: The Dasher D. And that's probably its most printable nickname
The Burninator: The Firestarter mech; also the Ignis IFV and Salamander Battle Armour
Slapjack: The Blackjack
Turkey: the Turkina
Daisy: the Daishi
While technically a videogame mod, the names given by fans for Mech variants in Mechwarrior: Living Legends fit in here as well. Some examples are "Mr. Bubbles" (Atlas), "Beat Stick" (Mad Cat Mk. II), "Scat" (Shadow Cat) and "Arrowpult" (Catapult with Arrow IV)
Wobbies, Wobblies, Toaster Worshippers: the eccentric (later genocidal) Word of Blake.
PAD — Pop-and-Drop, a tactic in online games where you would pop out of cover just long enough to fire, then drop out of sight to recycle weapons. Also known in Mechwarrior 4 circles as poptarting, referencing both the visual of toaster pastries suddenly popping up out of a toaster and their implied cheapness.
Underweight Heavy — any mech under 60 tons with a top speed of 64 kphnote 4 movement points while walking, 6 while running or less, such as the Panther or Hunchback
Zombie - A 'Mech that carries primarily energy weapons, maximum armor, standard or compact engines and/or gyros to a degree that it takes pretty much a center torso coring to defeat.
Flashbulb - A laser-(or sometimes PPC)only 'Mech.
Fourth of July - When a mech with a large number of Rocket Launchers fires them all at once; especially if it hits with very few of them.
Flailing Death - Repeatedly and spectacularly failing Standing Piloting Rolls to the point where the 'Mech destroys itself in the process. AKA: Breakdancing. Emphasis on the 'break'. Which leads to the dreaded...
Seatbelt Check - the piloting roll required to avoid pilot damage when a 'Mech falls.
Sponge - a 'Mech that through a combination of luck and good positioning, takes a huge amount of damage and keeps going. ANY 'Mech can sponge, as its a factor of taking more damage than you should be able to.
The Bushwacker in MechWarrior 4 is an infamous sponge, due to its tendency to spread damage around its narrow and angular torso.
Donut is exactly the opposite, where an otherwise pristine mech take all its damage to just its center torso, and dies.
Highlander Burial - a Death From Above maneuver (jumping on top of another 'Mech) performed by a 90-ton Highlander (especially on a smaller 'Mech), which can make it seem like the victim is being driven into the ground.
Lawn Dart Check - specifically for those who play with aerospace fighters or most other conventional aerodyne aircraft, which, if they take any hit while at speed in atmosphere, are required to make a roll against a random directional change...including pointing the nose down towards the ground. At full throttle. So named for the visual of metal fins sticking out of a honest-sized hole in the ground evoking the almost extinct game of lawn darts.
Clan Jade Falcon has accumulated several (usually not very flattering) nicknames, such as Clan Jade Turkey, Clan Green Burd and Clan Cockfalcon.
Hellbie Dice - specific to Classic Battletech, spread through its online community. Named for JadeHellbringer, a forum moderator and community veteran—specifically, his terrible luck in rolling dice. It refers to rolls that critically fail to such an absurd, game-ending degree that they become epic failure, mostly through a combination of Disaster Dominoes and defying the law of averages. Miss easy shots? It happens. Jam one of your guns in the process? Bad luck (and a 1 in 36 chance). Jam a gun on your first turn? Lousy luck, but entirely possible. Jam 70% of your 'Mech's guns, get rendered almost useless on your first turn as a result, then get killed by a damaged 'Mech 30 tons lighter than you? Now it's Hellbie dice.
Fucking Game's Unplayable - Gee, wonder why they went out of business...
TSR (D&D's original publisher)
They Sue Regularly - due to the company's draconian policy about fansites back in the early days of the Internet. Again, no wonder they went out of business.
T$R - Derisive nickname for later-era TSR, due to both their sue-happy tendencies (see above) and their increasing product proliferation.
Poker: All the 169 possible poker hands (in Texas Hold'em) have their individual nicknames. Many more than one. Most famous are "American Airlines" for two aces, "Anna Kournikova" for ace-king, "ducks" for deuces, "cowboys" for kings, "fishhooks" for jacks, "snowmen" for eights, "beer hand" for seven-two offsuit... For a more-or-less exhaustive list, look here.