Happiness

Happiness is a number between 0 and 255 that gauges how friendly a Pokémon is towards its trainer.

Walking with or leveling up the Pokémon will raise happiness. Capturing the Pokémon in a Luxury Ball or letting the Pokémon hold a Soothe Bell will cause happiness to rise quicker. Capturing the Pokémon in a Friend Ball will set its initial happiness to 200. However, letting the Pokémon faint will lower happiness, and trading the Pokémon will reset the value to the Pokémon's base happiness.

Evolution

A happiness of 220 or more upon leveling up is necessary to evolve:

• Golbat->Crobat
• Eevee->Espeon (day)
• Eevee->Umbreon (night)
• Pichu->Pikachu
• Igglybuff->Jigglypuff
• Munchlax->Snorlax
• Swadloon->Leavanny

Bugs

• A Pokémon caught with a Friend Ball will appear to have a happiness of 200 immediately after it is caught, but will revert back to its normal base happiness after gaining or losing happiness.