Where to find Old Rod, Good Rod, and Super Rod in Pokémon Brilliant Diamond, Shining Pearl
Fishing is a staple in every main series Pokémon game, which acts as another way for the player to encounter specific Pokémon in different regions — more specifically, Water types that might not appear through other methods.
The actual mechanic has changed over the years, but at its core is fishing Pokémon goes to the player being given some form of the Fishing Rod Key Item and then using it to encounter Pokémon in the waters scattered throughout the area they’re exploring.
In Brilliant diamond and Shining pearls, players will once again have access to three different Fishing Rods throughout their adventure in Sinnoh: Old, Good, and Super Rod.
Each stick works in the exact same way, but higher quality bars will help you find rarer, more powerful Pokémon depending on where you use them. For example, the Old Rod is generally known only for allowing the player to encounter Magikarp and occasional Pokémon like Tentacool or Goldeen, while the Super Rod will give the player access to Gyarados and Poliwhirl.
Each separate Fishing Rod is given to you for free just by talking to the NPCs in the underworld, but you will only be able to get the old Fishing Rod and the Good Fishing Rod before BDSP’s post-game.
Old Rod is located just west of Jubilife City at one of the route connecting stations. There you will find a Fisherman who will give you an Old Rod, allowing you to fish Magikarp in any body of water… and that’s about it.
Your goal as an aspiring Fisherman should be to obtain the Good Rod, located on the East Side, just outside of Hearthome City. Another Fisherman NPC will be on your way as you leave the big city and enter Route 209.
Good Rod will open up more options for you, allowing you to encounter stronger Waters like Remoraid. However, the options for Water-type using this method are still rather fuzzy compared to just surfing.
You won’t get the Super Rod until later in the game. You’ll need to go to the Battle Resort after becoming the Champion of Sinnoh and get the National Pokédex, then talk to a Fisherman using the 225 Street entrance.
https://dotesports.com/pokemon/news/where-to-find-the-old-rod-good-rod-and-super-rod-in-pokemon-brilliant-diamond-shining-pearl Where to find Old Rod, Good Rod, and Super Rod in Pokémon Brilliant Diamond, Shining Pearl