Battle leaders over and over again....

First you save in front of a PC and then you go and battle the Gym and its leader. When you finish, go and clone the pokemon that grew levels. When you turn your game back on you will be in the Pokemon center BEFORE you battled the leader but if you look in your PC you will find the Cloned Pokemon. Exchange the pokemon and save when you have your raised ones in your party then you can do it again.
Note: This trick will fill up your boxes so every three times you do this trick release the extra pokemon or switch boxes.

Contributed by: Thing in the Swamp 

All Three Starters on one cartridge!

This glitch works on all versions, and involves the duplication glitch. First, start a new game. Then, before you go to Professor Elm's lab, save the game, then play the game as normal (DON'T SAVE) until you gain one more Pokemon and the ability to use boxes. Once you access the box, put your starter in the box, and then perform the duplication glitch, and, in turn, reset the game. You will start before you get your starter while you still have your previous starter in the box. Repeat this process twice, each time for a different starter, so that you have all three on the cartridge, whether in your party or in your box. NOTE: Starters you acquire from duplication are not registered in your Pokedex when you put them in your party. To register them, trade them to a different version and back.

Contributed by: noaisawsom123 

Drain Move Substitute Glitch

In the Japanese releases of Pokemon Red, Blue, Green, and Yellow, as well as all versions of Pokemon Gold, Silver, and Crystal, there is a glitch involving Substitute - no matter the accuracy of the move, if it is a move that absorbs HP (e.g. Absorb, Giga Drain, Mega Drain), the move will have a 100% chance to miss!

Contributed by: Anonymous 

Beat the Game Early (Non-JP Versions)

This glitch will allow you to skip the end of the game, the "end" that is found after beating the game's boss atop Mt. Silver and obtaining all 16 Badges. Begin by obtaining a party in the early game (if possible) of your starter Pokemon, Kenya (the Spearow given by a man in a gatehouse in Goldenrod), the Togepi from the Egg in the early game or the Egg itself, and a Wooper. Teach Wooper Return and put it as its topmost move in the list. Make Wooper hold TM12 (Sweet Scent).

Next, rename Boxes 2-8 in Bill's PC, without the quotes. (Note that "@" means the accented "e" found in "Pokemon" and "#" the symbol for "male".) For Box 1, "BOX1". For Box 2, "AAAp@D95". For Box 3, "'v,'v@@72'l". For Box 4, "'v#@,2p". For Box 5, "@#2'v9@22". For Box 6, "'v8##4'v't'l". For Box 7, 'v@@@4p'l@". And for Box 8, "4@d2'd". Stand in front of the console at the bottom-left of the main Pokemon Center counter, open the Pokedex, listen to Bellsprout's cry, and use the Coin Case. Exit out of the menu and all the sprites should be invisible. Walk up the stairs to the Center's second floor and then down again to warp to Mt. Silver. Speak with the invisible Red there to automatically end the battle with him (as the game makes all battles a win when you have no Pokemon). And now the game is beaten!

Note that, after this glitch, you will have no Pokemon and no ability to catch them (as you will not be able to enter battles without instantly winning). This is rectified by obtaining a gift Pokemon, such as the Eevee from Bill in Goldenrod or the Shuckle in Cianwood.

Contributed by: Anonymous 

Belly Drum Error

Belly Drum is a move which normally maximizes the user's Attack to quadruple its normal value while simultaneously removing 50% of their current HP. Thus, the move isn't supposed to function if the user's HP is under 50%. However, you can still use Belly Drum: if you do so, the game will claim that it failed, but it actually does raise your Attack by 2 stages (like x1.00 Attack to x2.00 Attack). This is because the command for Belly Drum is akin to 6 Swords Dances: however, 1/6th of the stat-boosting effect is erroneously applied prior to the HP deduction.

Contributed by: Anonymous 

Bug-Catching Contest Pokemon Duplication (JP v1.0 Only)

This glitch allows you to copy Pokemon with the use of only one cartridge of a game. You will need six Pokemon for this, two of which are filler. In the second slot, you want the Pokemon of the desired species. In the sixth slot, you want the Pokemon of the desired nickname, gender, types, moveset, statistics, and IVs and EVs. (Thus, if the sixth Pokemon is Shiny, so shall be the resultant Pokemon.) The other four can be filler Pokemon, but be sure someone in the party can use Fly or Teleport.

Begin by putting the Fly/Teleport Pokemon in the first slot of the party. Now, deposit the third, fourth, fifth, and sixth Pokemon in your party into the PC. Enter the Bug-Catching Contest on Tuesday, Thursday, or Saturday per the in-game clock and go to the front of side exits when you are in the contest. When asked to quit, say "No" and then Fly or Teleport away. Put the second Pokemon in your party into the PC. Save and reset the console and then return to the National Park. Speak with the guard at the front or side entrances and opt to quit the contest.

After learning the results of the contest, you will receive a copy of the sixth Pokemon in the party, who is of the second Pokemon's species.

Contributed by: Anonymous 

Pokedex Diploma

By capturing every Pokemon in the Kanto and Johto Pokedexes - aside from Mew and Celebi, which are optional - you will be able to speak with the Game Freak director in Celadon City to obtain a diploma recognizing this achievement.

Contributed by: Anonymous 

Easy Shiny Ditto/Mew

Note that this glitch involves trading between Pokemon Red/Blue/Green/Yellow (R/B/G/Y) and Pokemon Gold/Silver/Crystal (G/S/C). It will easily result in a Shiny Ditto or Mew, which will have above-average stats, as is the norm in Pokemon G/S/C.

First, you must trade any Shiny Pokemon from Pokemon G/S/C to Pokemon R/B/G/Y. Any Shiny Pokemon will work, including the scripted Shiny Red Gyarados you encounter during gameplay. Next you need to encounter a Wild Ditto: Mew will also work if you use any of the glitch variations to encounter a Wild Mew in R/B/G/Y. While in battle, wait until Ditto or Mew Transforms into the Shiny Pokemon, then simply catch the Ditto or Mew.

Once you've done so, trade that Ditto or Mew to Pokemon G/S/C. In doing so, you'll discover that said Ditto or Mew is Shiny.

Contributed by: Anonymous 

Reset Game Time

To reset the game time, at the title screen hold Down+Select+B. You'll need a password next, see the Time Reset FAQ on how to generate your unique password.

In the Korean versions, this password is the same password as in Pokemon Crystal instead:

- Hold Down, Select, B
- Release Down and B
- Hold Left and Up
- Release Select

Contributed by: oblivion from aoc 

Easy Breeding!

If you capture a Ditto you can use that for breeding. The Ditto will act as the female, so you wont have to get two of each type of Pokemon that you want the baby form of it. For Example just breed a Ditto and a Pikachu, and you will get a Pichu.

Contributed by: Elements_Master 

Avoid random battles

When you walk up to the edge of grass use cut and the grass will be gone. No more random battles.

Contributed by: InvaderGrr 

Duplication

NOTE: This requires at least two pokemon, and access to a PC.
First, take the pokemon you want to duplicate, put it into your group. Make sure you have a box with at least one free slot. Save your game in front of your PC. Then, go to the box, and deposit the pokemon. Exit the box, go to ''Change Box,'' select any box, and while it's saving, turn off the Gameboy.

NOTE: Make sure that you do it while the message ''Saving, do not turn off the power'' is still there. Otherwise it will not work.

Turn on the Gameboy, the box should be the one that you deposited the pokemon in. You should have the pokemon in your group and have the same pokemon in your group.

Contributed by: UltiVegito2 

Drain Move Substitute Glitch

In the Japanese releases of Pokemon Red, Blue, Green, and Yellow, as well as all versions of Pokemon Gold, Silver, and Crystal, there is a glitch involving Substitute - no matter the accuracy of the move, if it is a move that absorbs HP (e.g. Absorb, Giga Drain, Mega Drain), the move will have a 100% chance to miss!

Contributed by: Anonymous 

Internal Clock Reset

At the title screen, do the following:

- Hold Down, Select, B
- Release Down and B
- Hold Left and Up
- Release Select

From there you should be allowed to enter a password to re-enter your game. This varies upon certain factors of your internal game's state - your name, money, and ID, namely. Calculators for the process can be found elsewhere.

Contributed by: KeyBlade999 

Obtain GS Ball and Capture Celebi (3DS Virtual Console)

Exclusive to the 2018 3DS Virtual Console release of Pokemon Crystal, the player is able to obtain a GS Ball. This is done by progressing through the game until the Elite Four is defeated. At that point you can speak with the attendant in the Goldenrod City Pokemon Center and obtain the GS Ball. Bring this to Kurt in Azalea Town; wait the prescribed 24 hours and he'll direct you to the shrine in Ilex Forest where you can catch a Level 30 Celebi.

Unlike the original release of the game, this method of capturing Celebi exists in all regions in which the game is distributed (as opposed to just Japan) and is available by default, the VC port having altered the game slightly to make this possible. The Celebi can be Shiny as well, and it may be transferred to Pokemon Bank.

Contributed by: Anonymous 

Duplicate TM24s (DragonBreath)

After beating Claire in the eighth gym, you are tasked with going into the Dragon's Den. Go there, and have all of your Pokemon poisoned. Complete the elder's quiz in the den, but do not leave; instead, walk around until your entire party faints and you white out. Go visit Claire in the gym to get TM24 from her there, and then go into the elder's building in the Den for her to give you another. (This occurs because the game thinks by leaving without receiving the TM you were already given it but didn't have it. Since you didn't trigger the actual event in which Claire gave it to you, you can get both TMs.)

Contributed by: Anonymous 

Obtain Huge Sums of Money (German Pokemon Crystal, GBC Only)

Start a new game and play as normal until you receive the Pokedex and defeat your rival for the first time (the trainer named "???"). At that point, use the Pokemon Center healing station, visit the Poke Mart, and buy 1-2 Potions. Return to Route 30 and fight a Weedle, and try to get Poisoned from its Poison Sting attack (~30% chance). Afterwards, with your Pokemon poisoned, walk back to Professor Elm's lab: use the Potions you bought to ensure your Pokemon does not faint on the way.

Speak to Elm. After the cutscene, while in New Bark Town, walk around until your Pokemon faints from poisoning. This will warp you back to Cherrygrove. Next, you need to fill your first PC box and your party with Pokemon. After doing so, ensure that your filled PC box is selected, and walk back to New Bark Town: on the way, you'll be forced into a Pokemon capture tutorial (which we skipped by warping to Cherrygrove by fainting).

This glitch has various effects depending on the game version (Gold/Silver/Crystal), region, and whether it is on 3DS Virtual Console or an actual GBC. The only time this seems to have any useful effect is on the GBC German version of Pokemon Crystal: executed here, among the glitchy effects are the person who teaches you to capture Pokemon handing you a large amount of money. This sum somewhat ranndom, and if above the normal maximum, and reduced to 999,999 after. However, this money will also stick around after you save and reload the game!

Contributed by: Anonymous 

Obtain Evolution Stones More Quickly

Before attempting this, make sure only the person/people with the stone(s) you want are in your Pokégear. This will speed up this process, which can take some time.

To do this, head to your home in New Bark Town, then talk to Mom. After telling her "no" when she asks about saving your money, answer "yes" when she asks about Daylight Saving Time. After you cycle Daylight Saving Time on/off a few times, you'll receive a phone call from someone in your Pokégear. Continue to repeat this and eventually you will be offered the stone you want!

Contributed by: StarshineM 

Obtain all 3 starters without trading or using cheat codes

Start the game normally and save prior to choose your starter, then play normally until you beat your rival and get the 5 pokeballs. On the way back to Cherrygrove catch at least 2 more pokemon, then store your starter and one of the pokemon you caught and then switch to other box and when it asks to save reset the game a second after the "... DON'T TURN OFF THE POWER." message shows up. If done correctly you should be back to Elm's lab and ready to pick the second starter, this time you only need to get to Cherrygrove, check the pc, the stored pokemon should be there, just withdraw them and store the starters and once again do the change box/reset during the save part and you should be back at Elm's lab ready to pick the last starter, once back in Cherrygrove check the pc and the other two starters should be there.

Note: The first two picked starters will not register in the pokedex, unless you breed them.

Contributed by: darkgoku123 

Belly Drum Error

Belly Drum is a move which normally maximizes the user's Attack to quadruple its normal value while simultaneously removing 50% of their current HP. Thus, the move isn't supposed to function if the user's HP is under 50%. However, you can still use Belly Drum: if you do so, the game will claim that it failed, but it actually does raise your Attack by 2 stages (like x1.00 Attack to x2.00 Attack). This is because the command for Belly Drum is akin to 6 Swords Dances: however, 1/6th of the stat-boosting effect is erroneously applied prior to the HP deduction.

Contributed by: Anonymous 

Pokedex Diploma

By capturing every Pokemon in the Kanto and Johto Pokedexes - aside from Mew and Celebi, which are optional - you will be able to speak with the Game Freak director in Celadon City to obtain a diploma recognizing this achievement.

Contributed by: Anonymous 

Easy Shiny Ditto/Mew

Note that this glitch involves trading between Pokemon Red/Blue/Green/Yellow (R/B/G/Y) and Pokemon Gold/Silver/Crystal (G/S/C). It will easily result in a Shiny Ditto or Mew, which will have above-average stats, as is the norm in Pokemon G/S/C.

First, you must trade any Shiny Pokemon from Pokemon G/S/C to Pokemon R/B/G/Y. Any Shiny Pokemon will work, including the scripted Shiny Red Gyarados you encounter during gameplay. Next you need to encounter a Wild Ditto: Mew will also work if you use any of the glitch variations to encounter a Wild Mew in R/B/G/Y. While in battle, wait until Ditto or Mew Transforms into the Shiny Pokemon, then simply catch the Ditto or Mew.

Once you've done so, trade that Ditto or Mew to Pokemon G/S/C. In doing so, you'll discover that said Ditto or Mew is Shiny.

Contributed by: Anonymous 

Freeze your Game Clock

This is strange, but also permanent, so only do this if you want your clock to remain set on a certain day. To do this, go to Vermillion City and talk to the Machop that is stomping on the ground. After you talk to him, open your Pack, go to Coin Case, and look at how many coins you have. Your game will either freeze or reset, so you must reset if it freezes. When you do, your game clock will be frozen in that exact time unless you use another code to change the time, which is possible.

Contributed by: Jelly Soup 

Bypass random encounters in grassy areas with HM01 -- Cut.

Once you've obtained HM01 -- Cut, you can use it to teach said technique to select Pokémon. In addition to its primary use of cutting down small trees which block your path, it can also be used to cut grass in order to bypass random encounters.

Note: Grass grows back after exiting/reentering an area.

Contributed by: KeeperBvK 

Easy Breeding

If you capture a Ditto you can use that for breeding. The Ditto will act as the female, so you wont have to get two of each type of Pokemon that you want the baby form of it. For Example just breed a Ditto and a Pikachu, and you will get a Pichu.

Contributed by: Elements_Master 

Duplicate Pokemon

You can duplicate pokemon whether or not it holds an item. Get to a computer and save it, making sure that you have atleast one more room for the cloned pokemon. Deposite the poke'mon that you want to duplicate. Now change boxes, when you change you'll automatically save, so say yes when it asks you to save. When it says "Saving, don't turn off the power", turn it off then on. When you gain control, you'll be holding the regular pokemon and there will be the cloned pokemon in Bill's PC. Use this glitch at your own risk, as it is possible to corrupt save data.

Contributed by: Dark Rolling Stones 

Freeze your Game Clock

This is strange, but also permanent, so only do this if you want your clock to remain set on a certain day. To do this, go to Vermillion City and talk to the Machop that is stomping on the ground. After you talk to him, open your Pack, go to Coin Case, and look at how many coins you have. Your game will either freeze or reset, so you must reset if it freezes. When you do, your game clock will be frozen in that exact time unless you use another code to change the time, which is possible.

Contributed by: Jelly Soup 

Get all three starters

First start a new game. Then after you have selected a starter pokemon, work your way through the game, not saving at all, until you can catch pokemon. Catch any other pokemon then deposit your starter into the PC box. After that, change boxes and when it asks you to save click "yes". When it starts saving reset(or turn off) the game. When you go on your main file the starter should be in the box that it was placed in. Make sure before you do this glitch to go on your main file and move the number one pokemon in the box, as the starter will replace it. Use this glitch at your own risk, it can mess up game data.

Contributed by: samishxc 

Easy Shiny Ditto/Mew

Note that this glitch involves trading between Pokemon Red/Blue/Green/Yellow (R/B/G/Y) and Pokemon Gold/Silver/Crystal (G/S/C). It will easily result in a Shiny Ditto or Mew, which will have above-average stats, as is the norm in Pokemon G/S/C.

First, you must trade any Shiny Pokemon from Pokemon G/S/C to Pokemon R/B/G/Y. Any Shiny Pokemon will work, including the scripted Shiny Red Gyarados you encounter during gameplay. Next you need to encounter a Wild Ditto: Mew will also work if you use any of the glitch variations to encounter a Wild Mew in R/B/G/Y. While in battle, wait until Ditto or Mew Transforms into the Shiny Pokemon, then simply catch the Ditto or Mew.

Once you've done so, trade that Ditto or Mew to Pokemon G/S/C. In doing so, you'll discover that said Ditto or Mew is Shiny.

Contributed by: KeyBlade999 

Bug-Catching Contest Pokemon Duplication (JP v1.0 Only)

This glitch allows you to copy Pokemon with the use of only one cartridge of a game. You will need six Pokemon for this, two of which are filler. In the second slot, you want the Pokemon of the desired species. In the sixth slot, you want the Pokemon of the desired nickname, gender, types, moveset, statistics, and IVs and EVs. (Thus, if the sixth Pokemon is Shiny, so shall be the resultant Pokemon.) The other four can be filler Pokemon, but be sure someone in the party can use Fly or Teleport.

Begin by putting the Fly/Teleport Pokemon in the first slot of the party. Now, deposit the third, fourth, fifth, and sixth Pokemon in your party into the PC. Enter the Bug-Catching Contest on Tuesday, Thursday, or Saturday per the in-game clock and go to the front of side exits when you are in the contest. When asked to quit, say "No" and then Fly or Teleport away. Put the second Pokemon in your party into the PC. Save and reset the console and then return to the National Park. Speak with the guard at the front or side entrances and opt to quit the contest.

After learning the results of the contest, you will receive a copy of the sixth Pokemon in the party, who is of the second Pokemon's species.

Contributed by: KeyBlade999 

Belly Drum Error

Belly Drum is a move which normally maximizes the user's Attack to quadruple its normal value while simultaneously removing 50% of their current HP. Thus, the move isn't supposed to function if the user's HP is under 50%. However, you can still use Belly Drum: if you do so, the game will claim that it failed, but it actually does raise your Attack by 2 stages (like x1.00 Attack to x2.00 Attack). This is because the command for Belly Drum is akin to 6 Swords Dances: however, 1/6th of the stat-boosting effect is erroneously applied prior to the HP deduction.

Contributed by: KeyBlade999 

Beat the Game Early (Non-JP Versions)

This glitch will allow you to skip the end of the game, the "end" that is found after beating the game's boss atop Mt. Silver and obtaining all 16 Badges. Begin by obtaining a party in the early game (if possible) of your starter Pokemon, Kenya (the Spearow given by a man in a gatehouse in Goldenrod), the Togepi from the Egg in the early game or the Egg itself, and a Wooper. Teach Wooper Return and put it as its topmost move in the list. Make Wooper hold TM12 (Sweet Scent).

Next, rename Boxes 2-8 in Bill's PC, without the quotes. (Note that "@" means the accented "e" found in "Pokemon" and "#" the symbol for "male".) For Box 1, "BOX1". For Box 2, "AAAp@D95". For Box 3, "'v,'v@@72'l". For Box 4, "'v#@,2p". For Box 5, "@#2'v9@22". For Box 6, "'v8##4'v't'l". For Box 7, 'v@@@4p'l@". And for Box 8, "4@d2'd". Stand in front of the console at the bottom-left of the main Pokemon Center counter, open the Pokedex, listen to Bellsprout's cry, and use the Coin Case. Exit out of the menu and all the sprites should be invisible. Walk up the stairs to the Center's second floor and then down again to warp to Mt. Silver. Speak with the invisible Red there to automatically end the battle with him (as the game makes all battles a win when you have no Pokemon). And now the game is beaten!

Note that, after this glitch, you will have no Pokemon and no ability to catch them (as you will not be able to enter battles without instantly winning). This is rectified by obtaining a gift Pokemon, such as the Eevee from Bill in Goldenrod or the Shuckle in Cianwood.

Contributed by: KeyBlade999 

Drain Move Substitute Glitch

In the Japanese releases of Pokemon Red, Blue, Green, and Yellow, as well as all versions of Pokemon Gold, Silver, and Crystal, there is a glitch involving Substitute - no matter the accuracy of the move, if it is a move that absorbs HP (e.g. Absorb, Giga Drain, Mega Drain), the move will have a 100% chance to miss!

Contributed by: KeyBlade999