Happiness is when your current Pokémon grows more friendly, and is a number between 0 and 255. It is sometimes necessary in the evolution of certain Pokémon, such as evolving Eevee into Umbreon or Espeon.
There are a 2 methods of increasing happiness in a pokemon:
- Leveling up (adds 2 to happiness).
- Walking (256 steps adds 1 to happiness).
- Keeping your pokemon out of it's pokeball for a while (Adds varied amount of happiness depending on how long it is out).
- Feeding it certain berries, experiment with different berries (Adds around 10 happiness per edible berry).
Catching a pokemon with a luxury ball adds 1 extra happiness every time you do one of the above. If you give a Pokémon a Soothe Bell, it will also increase the rate at which happiness is gained. Alternatively, catching a Pokémon with a Friend Ball immediately adds 200 happiness to the pokemon.
If a Pokémon faints, its happiness will decrease, and trading a Pokémon will immediately return the Pokémon's happiness to 0.