The format and rules for the 2014 Pokémon video game season have been announced and posted on the official Pokémon website.

New Updates:

  • Only legitimate versions of Pokémon X or Pokémon Y can be used in Play! Pokémon tournaments
  • Players may use Pokémon from the Central Kalos Pokédex from #001 to #150, Coastal Kalos Pokédex from #001 to #153, or Mountain Kalos Pokédex from #001 to #147.
  • Pokémon are allowed to Mega Evolve.
  • Pokémon above Level 50 are permitted, but they are auto-leveled down to 50 for the duration of battle
  • Kalos Native: Pokémon used in the Standard Format must be native to the Kalos region in Pokémon X or Pokémon Y. A native Pokémon is a Pokémon that is hatched or caught in Pokémon X or Pokémon Y. Pokémon that have been transferred to Pokémon X or Pokémon Y via Pokémon Bank or Poké Transporter are not native.

Source: http://assets22.pokemon.com/assets/cms/pdf/op/tournaments/2014/Play_Pokemon_VG_Rules_and_Formats_2014.pdf