A new Global Battle Union tournament is about to begin for players of Pokémon Black Version or Pokémon White Version. The 2012 Autumn Friendly features Double Battles online via Wi-Fi.

Competition Details:

Competition Dates: 00:00 UTC, Friday, September 14, through 23:59 UTC, Monday, September 17, 2012
Registration Period: 00:00 UTC, Thursday, September 6, through 23:59 UTC, Thursday September 13, 2012
Participant Limit: 50,000 (limit subject to change; first come, first served).
Competition Rules: Battle Format: Double Battle, Rankings will be decided based on player Ratings at the end of the competition. Players may use Pokémon found in the Pokémon Black Version or Pokémon White Version National Pokédex, from No. 001–646. The following Pokémon cannot be used in this competition: Mewtwo, Mew, Lugia, Ho-Oh, Chatot, Celebi, Kyogre, Groudon, Rayquaza, Jirachi, Deoxys, Dialga, Palkia, Giratina, Phione, Manaphy, Darkrai, Shaymin, Arceus, Victini, Reshiram, Zekrom, Kyurem, Keldeo.

Sources: http://pglhelp.pokemon.com/en/gbu/autumn_friendly_2012/ and http://www.pokemon.com/us/pokemon-news/pgl_2012_autumn_friendly_announce-2012-08-29/