This glitch will work in all three versions of the game. Unlike Missingno, it will not alter or corrupt any data on your save files.

To begin, simply make your way to Cerulean City, making sure to catch an Abra from Route 4 along the way. Next, you must visit the Pokémon Center. This step is vital in obtaining the glitch. When this is step is complete, you must travel past the Nugget Bridge to Route 25, and get to the area with a Youngster looking upwards at two blank squares. Position yourself to the left of the furthest square from the Youngster, then walk in front of him whilst pressing the START Button at the same time. If you have done this correctly, the Pause Menu will be open. Now, you must use Abra’s Teleport move, which can be done by going to your Pokémon sub-menu and selecting Abra from the list. The Youngster will spot you, but you will be warped away to the Pokémon Center in Cerulean City.

If you have done everything correct, you will not be able to open the Pause Menu. Now, walk back to the Youngster without encountering any Pokémon or trainers. Walk in front of him in the same way as before, but be careful because if you stand directly before him, the game will crash. He will see you, and then you must win the battle against the Youngster. After defeating him, the Pause Menu will be usable once more. Now, you must walk back in the direction of Cerulean City. When you reach the border between Route 24 and 25, the menu will pop up. Simply close it by pressing B, and a wild encounter will occur. As you’ve probably guessed, the Pokémon you encounter will be Mew. Simply catch it, and your mission is complete.

This glitch will work on all three version of the game.

It is especially helpful in Pokémon Yellow, as your starter Pokémon is not exactly equipped to deal with Rock and Ground types, despite what the animé would have you believe. It could take you a while to train your team up to the standard to face Brock, but if you want to go forward without facing him, there is a way to do so.

Go to the east of Pewter City, then walk in front of the man who will guide back to the gym if you have not beaten Brock whilst pressing the START button. If you have done this right, the Pause Menu will open before he sees you. Close the menu, then keep walking forward whilst pressing START to open the menu each time. Eventually you will reach Route 3, and you will have bypassed the barricade. A word of caution, you will be pulled back to the gym when you re-enter Pewter City if you do not repeat the same steps in reverse.

This is probably the most infamous glitch in the whole of the Pokémon series. It can only be performed safely on the Red and Blue versions of the game.

To prepare for this glitch, place the item that you want to duplicate into the sixth item slot in your bag. When you have obtained Fly and Surf, and can use them out of battle, simply go to Viridian City and talk to the old man who blocked your path at the beginning of the game. He will show you how to catch a Weedle. When the segment is over, fly to Cinnabar Island and Surf along the eastern shore of the island so you are half on land, and half on water. Travel up and down this boundary, and eventually you will encounter a mysterious entity known as a Missingno. Simply end the battle by running away. If you catch it, then it will mess up your Hall of Fame data, and quite possibly corrupt your save file. When you are outside of battle, the sixth item will now be multiplied to a near infinite amount.

This glitch will only work in the Yellow version of the game.

When you reach Cerulean City, you can head to the house at the top left of the map to meet a woman who is looking after an abandoned Bulbasaur. She is looking for a trainer who has Pokémon who clearly love their trainers, and as your Pikachu is out of its Poké Ball and following you around, that will be the deciding factor on whether she releases Bulbasaur into your care.

First, you must travel to a Pokémon Center and heal your party, then ensure Pikachu is in the first slot of your party. Next, you must have a Potion in your bag. Try to use it on Pikachu multiple times. The Potion will not be used because it does not need to be, but your electric friend’s happiness will increase everything you do so. Simply continue to do this until Pikachu is at its maximum happiness, which is indicated by it jumping up and down with delight, then speak to the woman to obtain Bulbasaur.

This glitch will only work in the Red and Blue versions of the game.

When you have obtained one of the three fishing rods that are hidden in various places around Kanto, simply go to the Cerulean City Gym and use your new rod as you would in the overworld. In Pokémon Yellow, you will be informed that you cannot use this item in that location, but in Red and Blue, it is possible to catch a small variety of water dwelling Pokémon using this method. This trick also works later in the game when you fight Lorelei of the Elite Four, as the water in her room is also populated by wild Pokémon.

Are there any tips that you find essential for the first three Pokémon games? Let us know your juicy titbits in the comments below.