Fishing
Fishing is a recreation that is commonly enjoyed in the Pokémon world.
In the games
Fishing is one way to catch Pokémon in the water. In fact, some Pokémon can only be caught by using a fishing rod. There are three fishing rods that are given out throughout the course of each game, and each one is given out by a Fishing Guru.
Equipment
Old Rod
An Old Rod is used to catch weak Water-type Pokémon, which usually means only low-level Magikarp. In the Generation I games and their Generation III remakes, it is given out by a Fishing Guru who can be found in a house next to the Pokémon Center in Vermilion City. In the Generation II games, he can be found in the Pokémon Center on Route 32. In the Generation III games, he is near the Gym in Dewford Town. In the Generation IV games, players can obtain an Old Rod from a fisherman in the house than connects Jubilife City to Route 218.
Good Rod
A Good Rod is used to catch Water-type Pokémon. It is an upgrade of the Old Rod. In the Generation I games and their Generation III remakes, it is given out by a Fishing Guru in a house in Fuchsia City. In the Generation II games, he can be found in Olivine City. In the Generation III games, he is on Route 118. In the Generation IV games, there is a fisherman on Route 209 with the Good Rod.
Super Rod
A Super Rod is an item used to catch strong Water-type Pokémon. It is an upgrade of both the Old Rod and Good Rod, and can be used to catch high-level Pokémon like Poliwhirl and Gyarados. In the Generation I games and their Generation III remakes, as well as in the Generation II games, the Super Rod's Guru can be found in a house on Silence Bridge. In the Generation III games, he is in a house by the Mossdeep Space Center. In the Generation IV games, the Super Rod is only obtainable after player obtains the National Dex. It is located in the Fight Area in the northwestern part of the area. There will be a fisherman who will give it to you.
Catching Pokémon (Generations I & II)
In Generation I and II, fishing is simply a matter of standing next to water and using the rod. Sometimes it will hook a Pokémon, and start a battle. Other times, it will catch nothing. There is a random chance of either happening, so if the rod catches nothing, feel free to cast it out again.
Generation III
Starting with Generation III, fishing became more complicated, as the player would have to pay attention and confirm as soon as the rod hooked a Pokémon, or else it would get away. In Ruby, Sapphire and Emerald, this required a series of confirmations to reel in better Pokémon. Generation III also introduced the ability for trainers to fish off the back of a Surfing Pokémon.
Generation IV
In Generation IV, the player would use the rod, and a exclamation mark-like sign would pop up above the player, noting that they should push the A button to start the battle with the pokémon they've encountered, using the rod. The exclamation mark-like sign is the same as when a trainer notices you, indicating a battle.
In the anime
Numerous episodes of the anime have featured the group fishing.
At the Safari Zone, a fishing rod is distributed with the Safari Balls.
Rather than using bait, lures with Pokémon designs are used. The fisherman in Whiscash and Ash believed that the secret to catching the Whiscash he was looking for was finding the right lure. Misty has a collection of lures, including a special lure based on herself that she believes is the best. She sent it to Ash as a gift in The Unbeatable Lightness of Seeing. Ash used this lure in Buizel Your Way Out of This to try and catch a powerful Buizel.