Getting Ditto is important for both IV breeders and shiny hunters, but Pokemon Brilliant Diamond and Shining Pearl have a new way of acquiring it than in the original DS games.
This means the Pokedex can easily be filled by battling in-game trainers and exploring the wild. After all 150 Pokemon have been registered, pay Professor Rowan a visit and the Dex will be upgraded to the National Dex.
After obtaining the National Dex, it’s time to catch Ditto. Using the Pokeradar function on the Poketch on Route 218 west of Jubilife City will give a 12% chance of finding the normal-type Pokemon. This is the best bet for finding higher-IV Ditto to aid in breeding a battle-ready team. There is also a small chance of finding Ditto in the Dazzling Cave or the Stargleam Cavern hideaway in the Grand Underground. If none spawn when in the hideaway, leaving and reentering the room has a chance of making a Ditto appear.
On Route 218, Ditto can be found at either level 29 or 30. At this point in the game it shouldn’t prove to be a difficult match. When Ditto uses its signature move, Transform, it will take on the look, moves, and cry of the active Pokemon.
Using the move False Swipe will get the Ditto down to just 1 HP to make capture easier. The odds can be further stacked by inflicting the sleep, paralysis, or frozen status effects. Using an Ultra Ball, Dusk Ball at night, or a Repeat Ball once one Ditto has already been caught will all add up to a higher chance of adding the Ditto to the Box. Using the Pokeradar allows players to catch high-IV Ditto to use for breeding battle-ready teams.