Sixth Pokémon generation

The Sixth Pokémon generation started with Pokémon X and Y. This is Pokémon's first fully 3D generation and the first generation to introduce the Fairy type and Mega Evolutions.

Pokémon

 * List of new Pokémon in Pokémon X and Y

There are a total of 72, bumping the total to 721 total Pokémon. The Pokémon start with Chespin and currently end with Diancie though there are two unreleased Pokémon, Hoopa and Volcanion.

In addition to the new Pokémon, several old Pokémon recieved Mega Evolutions. This is a powerful new form for certain Pokémon that improves their stats at the cost of the hold item. X & Y introduced 27 of them with several more introduced in Omega Ruby and Alpha Sapphire

Games
There have two sets of games for this generation, Pokémon X and Y, set in the Kalos region, and Pokémon Omega Ruby and Alpha Sapphire, remakes of Pokémon Ruby and Sapphire.

Spinoffs

 * Pokémon Battle Trozei
 * Pokémon Art Academy
 * Super Smash Bros. for Nintendo 3DS / Wii U

Metagame changes
The biggest Metagame change is the introduction of the new Fairy Type. Numerous Pokémon were reclassed to this type and several new Pokémon are this type. Other type matchup changes include Steel not being resistant to Dark or Ghost types anymore and new status immunities for other types like Electric types not being able to be paralyzed and Grass-types being affected by spores.

The other big metagame change was Mega Evolution. Several underused Pokémon are now viable and certain stronger Pokémon have alternate uses.

There were some smaller alterations. Several Pokémon had small base stat changes and some had different abilities introduced with this generation. Movepools were altered mostly incorporate the new Fairy type and other new moves. Fire Blast, Thunder, Blizzard, Hydro Pump and similar moves have been lowered from 120 base power to 110 base power. Some moves like Knock Off, have had an increase to 70 base power.