Pokémon: Brilliant Diamond & Shining Pearl brought a number of highly-anticipated changes from the original Diamond & Pearl, including a major expansion to the Underground, but players still need to get the Explorer Kit to venture into it. The new Grand Underground brings back many functions like treasure hunting and Secret Bases, adding new and exciting features like Pokémon Hideaways. It also improves upon the original DS games’ local multiplayer with online communication support, allowing players to connect in the Grand Underground via the internet as well as a local connection.
Like the original Underground, the Grand Underground has six distinct sections, but these new cave systems now conform to the shape of Sinnoh’s overworld rather than forming a square. Its new Pokémon Hideaways are large rooms connected by the tunnels where various Pokémon will roam, some of which can only be found in this subterranean system. Each room has its own aesthetic theme, and some rooms also feature surfable water.
In order to access the Grand Underground and start spelunking, players will need to obtain the Explorer Kit. The Explorer Kit can be obtained from the Underground Man in Eterna City, who will also act as the player’s mentor and teach them everything they need to know about adventuring below ground.
How To Get The Explorer Kit In Pokémon: Brilliant Diamond & Shining Pearl
As soon as players arrive in Pokémon: Brilliant Diamond & Shining Pearl's Eterna City, they will come across the city’s Pokémon Center, which is right by the city's entrance. The home of the Underground Man is directly next door to the Pokémon Center with a sign out front. When players speak with the old man inside, he will introduce himself and give players the Explorer Kit before taking them back outside to show them how to use it. The Explorer Kit can be accessed from the Key Items Pocket in the menu, and it can be registered as a shortcut for easier use.
The Explorer Kit in Pokémon BDSP allows players to drop directly down into the massive structure of caves and tunnels below Sinnoh. Known as the Grand Underground, these caverns are full of treasures and Pokémon for players to collect as they explore. Pressing the Y button will allow players to return to the surface where they entered the Grand Underground.
After returning to the surface, the Underground Man will teach the player how to treasure hunt. By approaching an area marked with a yellow diamond on the Grand Underground map and pressing A, players can check for treasure in the surrounding area. Players must get as close to the mark as possible to be able to dig. There are Spheres, Fossils, Shards, and Pokémon Statues buried in the Grand Underground that players can uncover. Spheres and Shards can be used as currency traded for other items in the Grand Underground, and Fossils can be turned into Fossil Pokémon at the Oreburgh Mining Museum in Oreburgh City.
Once players have found some treasures, they can return to the Underground Man again to learn how to set up their very own Secret Base. He’ll give them the Digger Drill as a reward for treasure hunting, which can be used anywhere in the tunnels of the Grand Underground by approaching a wall and pressing the A button. Players can place any Pokémon Statues they dig up in their Secret Base, which will increase the spawn rate of those Pokémon in the Pokémon Hideaways. Digger Drills can only be used once, but if the player wants to move their Secret Base, they can trade Spheres for a new Digger Drill.
Pokémon: Brilliant Diamond & Shining Pearl are available on Nintendo Switch.