Every single Pokémon generation has a special game mechanic that makes each game a unique experience even for long-time fans of the series. For Pokémon Brilliant Diamond and Shining Pearl, this new aspect is the Grand Underground, which is a large maze of tunnels underneath the Sinnoh region.
Although the original Pokémon Diamond and Pearl had this as well, the remake has vastly changed this underground world, which means that both new and old players will likely get lost. Luckily, there are some quick and easy tips to learn that will help guide players through the labyrinth.
Look For Yellow Markers On The Mini-map
If the player looks at their mini-map while traveling through the underground tunnels, they will see yellow markers at certain spots within the tunnels that they have direct access to. These spots indicate which particular walls can be dug into for treasure. After pressing the "R" button near the marker's location, the player will see a bright sparkle on the wall, which shows exactly where to interact in order to start digging.
Once the player interacts with the wall, they will begin a minigame where they will have to find the treasure before the wall collapses. Each time the player re-enters the tunnels by either returning from the surface or by exiting a room, these locations will be randomized.
Use The Sledgehammer, Then The Pickaxe
While digging the wall, the player will need to find the hidden treasure by switching between two tools using the "R" button. These tools, the sledgehammer and the pickaxe, each have different abilities. The player should start with the sledgehammer first because it clears out more of the wall, which can help either find treasures or rule certain areas out.
But, since the sledgehammer causes the wall to collapse quicker, it should only be used at the start to help narrow the search down. After large sections of the wall have been uncovered, the pickaxe should be used for the smaller areas. Once the wall falls, any treasure not found is now lost. This addicting minigame alone makes the Grand Underground one of the best locations in Brilliant Diamond and Shining Pearl.
Make A Secret Base
Besides digging the walls for treasure, the player can also use a "digger drill" to dig into a wall and create a secret base. After being introduced to the Grand Underground by the Underground Man living in the house next to the Pokémon Center in Eterna City, the player will need to make sure to keep talking to him so that they can complete a few tutorial quests and gain items.
One of the quest awards is a digger drill, which the player can use on any wall to create their own secret base. But, they need to be careful about where they put it because the digger drill is a one-use item.
Place Statues In Secret Base
Although players are unable to place any traps or furniture in their secret base, they can place the Pokémon statues they obtain while digging the walls for treasure. Besides adding some aesthetic flavor to the player's little hobbit hole, the statues also increase the chance that players will encounter certain types of Pokémon underground.
Along with the statues, players can also find fossils, evolution stones, heart scales, and other useful treasures while digging. The spheres the player finds can be used to buy certain items underground.
Explore Pokémon Hideaways
One of the biggest additions to the underground in this remake is the Pokémon Hideaways. When the player first starts exploring the Grand Underground, each Pokémon Hideaway is marked on the map as a grey box with a question mark on it. But, once a player enters one, that particular room changes on the map to an image that signifies the room's biome.
Similar to the wild area in Pokémon Sword and Shield, the Pokémon in these rooms are seen moving around rather than randomly encountered, and the player will see certain types of Pokémon depending on the biome of the hideaway. If the player gets too close to one of them, they will notice the player and chase after them to start a battle.
Keep Revisiting Pokémon Hideaways
Besides the biome, the Pokémon in the hideaways also vary depending on how far into the game the player is. As the player progresses through the story and gains more Gym Badges, more types of Pokémon will continue to appear. Some of these powerful Pokémon can only be found underground, which means the player will need to keep returning to catch them and fill up the Pokédex.
All the Pokémon in the underground scale to the player's level, which means they will never be underleveled or overleveled. Also, many of the rooms have hidden items, so the player should keep returning to make sure they get them all.
Watch For Digletts and Dugtrios
While moving through the tunnels, the player will randomly encounter Digletts and Dugtrios that give pink sparkles. The Digletts give one sparkle each while the Dugtrios give three sparkles each, and these sparkles fill up the gauge under the mini-map. Once the player gains 40 sparkles, which maxes the meter, their likelihood of finding shiny Pokémon statues while digging increases.
Shiny Pokémon statues significantly increase the rate of rare Pokémon, and they are also just cool to have in the secret base. When the player leaves the Grand Underground, the gauge resets and they will need to collect all the sparkles again.
Buy From Hikers
If a player finds a random hiker NPC underground, the player can trade their treasures for spheres and spheres for items. For example, if the player has decided that they want to move their base to another location, they can buy more drills. Using the drill will move the secret base to another location, but it will also remove the base from the original location because the player can only have one base.
If the player is struggling because their base is too small to fit all their statues, then they can also pay these hikers to expand the base. This makes up for the fact that the player can only have one of these rooms.
Play With Friends
Although each player can only have one secret base, this doesn't mean that there can't be multiple secret bases in the Grand Underground. During multiplayer modes in the underground, players can visit other players' bases. This is significant because players can visit these other bases and switch the statue buffs to whatever the other player has, which helps the player get other types of Pokémon.
Connecting with friends also helps players find more hidden treasure. If one player is digging in a specific location, another player can then dig the wall in the same location even if there wasn't a mark on the map there originally.
Enter The Underground From Different Locations
When the player first enters the Grand Underground in Eterna City, they find themselves in one large section of the underground. But, there are six major sections of the Grand Underground, and they are not connected to each other. In order to reach these other sections, the player will need to enter this labyrinth from different areas on the surface.
Because of this, it is best to visit the Grand Underground in every major city. While some Sinnoh locations will put a player in the same section, other locations will correspond to other sections.