Pokémon that evolve from happiness:

Certain Pokémon evolve with happiness. Every Pokémon has happiness and happiness goes up to 255 points. Pokemon only need 220 points of happiness or more to evolve this way. Most Pokémon start with 70 points of happiness when you catch or hatch them. If you catch a Pokémon with a Luxury Ball, it will gain more happiness points when you do the things below that increase happiness. You can find how much happiness a Pokémon in your team by using the Pokétch App #6. This can be obtained from a girl in the Eterna City Pokémon Center. A Pokémon can have either no hearts, a small heart, 2 small hearts, or 2 big hearts. If your Pokémon has a Soothe Bell attached the gain in happiness is doubled. There are 2 places in the games where you can get a massage for your Pokémon daily, one lady in Veilstone, right beneath the Gym and another in the Resort Area Ribbon Syndicate. Also, walking for 256 steps give your Pokémon 1 point of happiness.

The move Return also varies based on happiness. It can have a base power of 102 with max happiness. The same is true for Frustration, only the less happiness the better.

Ways to Increase Happiness:

Ways to Decrease Happiness: