You'll see doors occasionally, on specific levels of specific dungeons. Behind these are treasures, items that power up certain types, or belong to legendary pokemon.
In Pokemon Mystery Dungeon: Explorers of Darkness, the TM for Shadow Ball can be found on B1F of Brine Cave after reaching the Gold Rank. It is located inside a locked room and requires a key to access.
in dungeons sometimes the kelcleon shop in town same thing but cheaper dungeon-9000$-10000$ town-8000$
sometimes in dungeons you will find a door if you have a key you can open it the door sometimes the door opens to a rare Pokemon that can be recruited or a rare item
They don't open dungeons, they open locked rooms within dungeons. Certain unique items can be found, like the Silk items, and treasure items for Legendary pokemon.
In Pokémon Mystery Dungeon: Explorers of Time and Explorers of Darkness, a Golden Apple is an item that can be used to increase a Pokémon's maximum belly capacity by 50 points. This can be particularly useful for sustaining longer explorations or challenging dungeons, as managing hunger is a key gameplay mechanic. Players can find or purchase Golden Apples throughout the game, making them a valuable resource for adventurers.
just like on the red versoin if u defeat a Pokemon thay MAY want to join. ther is a item that will boost the liklyhood of Pokemon joining called the friendship ribbon it is only avalible with a key or cheating>
The Enigma Part is a key item in Pokémon Mystery Dungeon: Explorers of Time used to unlock the Buried Relic dungeon. It is found on the 48th floor of the dungeon Waterfall Cave, and players need to retrieve it to access the Buried Relic and progress in the game.
In Aegis Cave
in some dungeons there will be doors you use the key on the doors while facing them
Its on floor 30 of mount Faraway. you need a key.
they are on the floors of higher leveled dungeons.
You can find them lying around in Solar Cave.