Diamond/Pearl/Platinum: Lost Tower; the Underground; found on wild Happiny and Chansey Heart Gold/SoulSilver: Rock Tunnel; Bug Catching Contest (first prize); Amity Meadow; found on wild Chansey Black/White: Challenger’s Cave; Black City shop B; during Dust Clouds; found on wild Happiny Black 2/White 2: Dust clouds inside the Relic Passage, Rebirth Mountain, and Clay Tunnel; White Forest X/Y: Unknown Dungeon (hidden on a rock to the left of Mewtwo); PokéMileage Club (balloon popping, level 2) Omega Ruby/Alpha Sapphire: Found on wild Happiny Sun/Moon: Paniola Ranch; “Path for Brilliant-Stone Hunting!” mission of Isle Aphun in Poké Pelago (available starting at Rank 2)

Diamond/Pearl: Trophy Garden; hatch the egg from the trainer in Hearthome City Platinum: Trophy Garden HeartGold/SoulSilver: Breed Chansey or Blissey equipped with a Luck Incense Black: Trade only White: White Forest Black 2/White 2: Hatch the egg from the trainer in Nacrene Gate X/Y: Breed Chansey or Blissey equipped with a Luck Incense Omega Ruby/Alpha Sapphire: Mirage Forest, Mirage Mountain Sun/Moon: Route 1, Route 4, Route 5, Route 6, Hau’oli City, Lush Jungle (only available by being called as an ally Pokémon in all cases)

Generation IV (Diamond/Pearl/Platinum/HeartGold/SoulSilver): 10:00 AM-7:59 PM Generation V (Black/White/Black 2/White 2): Spring: 10:00 AM-4:59 PM Summer: 9:00 AM-6:59 PM Autumn: 10:00 AM-5:59 PM Winter: 11:00 AM-4:59 PM Generation VI (X/Y/Omega Ruby/Alpha Sapphire): 11:00 AM - 5:59 PM Generation VII (Sun/Moon): 6:00 AM - 6:00 PM (Sun), 6:00 PM - 6:00 AM (Moon, which takes place 12 hours ahead of your device’s clock)

Generation IV (Diamond/Pearl/Platinum/HeartGold/SoulSilver): 10:00 AM-7:59 PM Generation V (Black/White/Black 2/White 2): Spring: 10:00 AM-4:59 PM Summer: 9:00 AM-6:59 PM Autumn: 10:00 AM-5:59 PM Winter: 11:00 AM-4:59 PM Generation VI (X/Y/Omega Ruby/Alpha Sapphire): 11:00 AM - 5:59 PM Generation VII (Sun/Moon): 6:00 AM - 6:00 PM (Sun), 6:00 PM - 6:00 AM (Moon, which takes place 12 hours ahead of your device’s clock)

Spring: 10:00 AM-4:59 PM Summer: 9:00 AM-6:59 PM Autumn: 10:00 AM-5:59 PM Winter: 11:00 AM-4:59 PM

If you’ve done this right, message should appear on the screen telling you that Happiny is now holding the Oval Stone. Happiny will keep the Oval Stone until you give it something different or it evolves.

If you’re in an area with many difficult Pokémon and you don’t want to risk having your low-level Happiny faint, you may want to use an Exp. Share item, which allows even Pokémon that don’t participate in the battle to gain experience points. [4] X Research source Other things that can boost the rate of experience gain include having a high affection level in Pokémon Amie (Gen VI) or Pokémon Refresh (Gen VII) and having Pass Power (Gen V) or O-Power (Gen VI) active.

Note that your Oval Stone will disappear after the evolution. Keep an eye on the clock as you get your Happiny experience points. If you battle long enough that your Happiny levels up during the night, it will not evolve into Chansey and you’ll need to wait for daytime or adjust the clock and try again.