Fishing Rods can be purchased in the PokeMart. The Fisherman sells the Old Rod, Good Rod, and Super Rod. The better the fishing rod, the better the Pokemon and loot you can fish up!
The Ice Rod and Fire Rod can be obtained in the ice and fire dungeons respectively.The Master Rod is the rarest fishing rod of them all! You get it as a reward for completing 200 PokeDex Research Tasks.
A fishing mini-game appears when you reel in a Pokemon! If you get a Magikarp on the mini-game, that means it's a tier 1-3 fish. If you get a Feebas, that means it's a tier 4 or higher.
You can add tackles to your fishing rod by speaking to the Fisherman in the PokeMart. All tackles have 100 uses. Once it runs out, you have to purchase a new one.
Enigma Tackle - Makes the fishing bar 50% bigger
Lansat Tackle - Doubles the chance of a rare fish
Salac Tackle - Increases bite-rate
Razz Tackle - Doubles Shiny Rate
Cheri Tackle - Doubles hidden ability rate
Kelpsy Tackle - Increases Magikarp chances
Aguav Tackle - Increases the chance of finding items
There are many unique forms of Magikarp each with different rarities! If you fish them up, you're given PokeDollars! The rarer the variant, the more PokeDollars you get!
Certain Pokemon such as Chi-Yu and Volcanion can only be obtained from lava fishing! You can fish in lava with the Fire Rod.