Generation 3

Generation 3 is the third installment to the Pokémon franchise. This Generation made a few drastic changes to the game, such as the replacement of DV with IV, full colour and many new items along with a few tweaks to some mechanics. This Generation includes the games Pokémon Ruby, Pokémon Sapphire, based in the region of Hoenn, and Pokémon Emerald, with the remakes of the Generation 1 games, Pokémon Fire Red and Pokémon Leaf Green, based in Kanto. Pokémon Ruby and Pokémon Sapphire were remade in Generation 6 as Pokémon Omega Ruby and Pokémon Alpha Sapphire.

Unlike Johto and Kanto before it, Hoenn does not connect to the past region like Johto did. This may explain why the Routes in Hoenn start with Route 101, rather than a continuation from Johto. Pokémon Ruby, Sapphire, and Emerald also feature two evil organizations, Team Aqua and Team Magma, instead of Team Rocket.

Mechanics
Like mentioned before, these games made many changes to mechanics to balance the game. A big addition was adding natures and abilities. They were aspects to a Pokémon that altered how their stats will end up as well as additional effects that usually benefit your Pokémon. DVs were completely replaced with IV (Individual Values) which worked similarly. They altered stats by a lesser factor but maxed at 31 rather than the DV system with 15.

EVs could no longer be used to max out every stat and was limited to 510 ev in total and 255 in individual stats. Weather effects in battle were also fully implemented.

Trivia

 * The Pokemon Shellos and Gastrodon were originally planned for these games but was added at each in development and scrapped due to time constraints. These Pokémon were then added to Gen 4 with 2 different forms