Welcome to the Old Gens megathread for VGC! Past formats see play in some grassroots tournaments such as World Cup of VGC among others. They can also be insanely fun to play casually with friends or users in the Pokemon Showdown! room. In this thread, you will be able to find helpful resources such as mini viability rankings, speed tiers, sample teams, and more! Feel free to post anything related to past VGC formats in this thread, including teams, replays, suggestions to a VR, or anything you feel like! Just be sure to post intelligently and don't flood the thread.
Notable Gen 7 mechanics different from Gen 8:
-Megas instantly gain their speed upon Mega-Evolution, but otherwise, dynamic speed does not exist in this format.
-Figy/Aguav/Wiki/Iapapa/Mago berry heal 50% of the max HP
-Disguise does not incur any chip damage when broken
-Aegislash has 150/150 stats in its given form, and King's Shield drops Attack by 2 stages
VGC 2017:
Ruleset: All Pokemon in the Sun and Moon Alola Pokedex except for Cosmog, Cosmoem, Solgaleo, Lunala, Necrozma, Magearna, Marshadow, and Zeraora. USUM Tutor moves are not permitted. Pokemon must be native to Alola to be eligible. Mega Stones are banned. In-Game Timer is 10 minutes of your time. Dark Void is banned.
Ruleset: All Pokemon in the Gen 7 National Pokedex except for restricted Legendaries and mythicals. Pokemon must be native to Alola to be eligible. Mega Stones are permitted. In-Game Timer is 5 minutes of your time. Dark Void is banned.
Sun Series: All Pokemon in the Gen 7 National Pokedex except for Mythicals are legal, however players are only allowed to choose 2 restricted Legendaries maximum for their team. Mega Stones, Z-Crystals, and the moves Dragon Ascent and Dark Void are banned. In-Game Timer is 7 minutes of your time.
Moon Series: All Pokemon in the Gen 7 National Pokedex except for Mythicals are legal, however players are only allowed to choose 2 restricted Legendaries maximum for their team. Mega Stones and the moves Dragon Ascent and Dark Void are banned. In-Game Timer is 7 minutes of your time.
Ultra Series: All Pokemon in the Gen 7 National Pokedex except for Mythicals are legal, however players are only allowed to choose 2 restricted Legendaries maximum for their team. In-Game Timer is 7 minutes of your time. Dark Void is banned.
Notable Gen 6 Mechanics:
-Critical Hits are a 1 in 16 chance
-Mega Evolutions gain their Speed boost the turn after Mega Evolving
-Thunder Wave has 100% accuracy and Paralysis quarters Speed
-Prankster will work on Dark types
-Confusion is a 50% chance for a self hit
-Parental Bond has a 1.5x multiplier for the second hit, and all -ate abilities such as Aerilate and Pixilate have a 1.3x multiplier
-Smeargle can use Dark Void
-All formats in gen 6 use a 15 minute live timer for the In-Game Timer
VGC 2014:
Ruleset: All Pokemon in any of the Kalos pokedexes with the exception of Mewtwo, Xerneas, Yveltal, and Zygarde. Pokemon must be Kalos native to be eligible to compete.
Ruleset: All Pokemon in the Gen 6 National Pokedex are legal, with the exception of restricted Legendaries and mythicals. Pokemon must be native to a Gen 6 game in order to be eligible to compete.
Ruleset: All Pokemon in the Gen 6 national dex are legal (barring mythicals), with a restriction of 2 maximum restricted Legendaries per team. Pokemon must be native to a Gen 6 game in order to compete.
Notable Gen 5 Mechanics:
-Gems for all types exist and have a 1.5x damage modifier
-Autoweather does not expire until it is overridden by another weather
-Electric types can be hit by Paralysis
-Grass types are not immune to powder moves (Sleep Powder, Spore, Rage Powder, etc.)
-Critical Hits are a 2x damage modifier
-Subsequent protects are half the chance of the previous protect
-Redirection moves have +3 priority
Notable VGC Mechanics:
-Pokemon from past gens can be used, allowing events such as Eruption Heatran or Follow Me Magmar
-All games have a 20 minute overall In-Game Timer
VGC 2011:
Ruleset: Pokemon from the Unova Pokedex only are permitted to compete. Reshiram, Zekrom, Kyurem, Victini, Keldeo, Meloetta, and Genesect are banned. Sky Drop is also banned.
Ruleset: Pokemon in the Gen 5 National Pokedex are legal, with the exception of restricted Legendaries, mythicals, and Therian formes. BW2 Move tutors are also not permitted. Sky Drop is banned.
GEN 7 
Gastrodon
Gyarados
Metagross
Mudsdale
Nihilego
Togedemaru
Hariyama
Magnezone
Persian-Alola
Pheromosa
Salamence
Tapu Bulu
Torkoal
Araquanid
Drifblim
Lilligant
Porygon-Z
Aerodactyl
Braviary
Clefairy
Drampa
Eevee
Gengar
Goodra
Politoed
Raichu-Alola
Smeargle
Vanilluxe
Vikavolt
Milotic
Volcarona
Aegislash
Gardevoir-Mega
Gothitelle
Nidoqueen
Stakataka
Tyranitar
Tyranitar-Mega
Bisharp
Latias
Latias-Mega
Ludicolo
Manectric-Mega
Nidoking
Scizor-Mega
Blaziken-Mega
Camerupt-Mega
Excadrill
Lurantis
Raichu
Suicune
Venusaur-Mega
Tsareena
Talonflame
Dialga
Ditto
Palkia
Shedinja
Zekrom
Necrozma (Ultra)
Lucario-Mega
Jumpluff
Umbreon
Aerodactyl-Mega
Bronzong
Mewtwo-Mega-Y
Salazzle
GEN 6 
Conkeldurr
Lucario
Chandelure
Machamp
Rotom-Mow
Scizor
Charizard-Mega-X
Meowstic
Blastoise-Mega
Gourgeist
Klefki
Reuniclus
Entei
Landorus
Rhyperior
Terrakion
Breloom
Blaziken
Clefable
Hitmontop
Jellicent
Raikou
Swampert
Togekiss
Weavile
Exeggutor
GEN 5 
