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If you grew up with a Game Boy in one hand and a rumor from the school bus in the other, you probably heard whispers about a strange creature called MissingNo. In Pokémon Red and Pokémon Blue, that bizarre glitch became famous for one big reason: it can multiply items. And not boring items, either. We are talking about Rare Candies, Master Balls, Nuggets, PP Ups, and all the little treasures that make a trainer feel like they found a secret door in reality.
This guide explains the classic item duplication trick in a clean, beginner-friendly way. It is based on the well-known Old Man glitch route that sends players from Viridian City to the coast of Cinnabar Island, where the game’s data handling gets wonderfully weird. The result is simple: the item in your sixth bag slot can jump by 128. That is why this trick has lived rent-free in Pokémon history for decades.
Before you start, one important note: this method is for Pokémon Red and Pokémon Blue. It is not the same process used in Pokémon Yellow. Also, glitches are glitches. They are fun, nostalgic, and occasionally chaotic. Save first. Your future self will appreciate the courtesy.
What You Need Before You Begin
To duplicate items in Pokémon Red or Blue, you should have a few things ready:
- Access to Viridian City
- Access to Cinnabar Island
- A Pokémon that can use Fly
- A Pokémon that can use Surf
- The item you want to duplicate placed in the sixth slot of your bag
- Fewer than 128 of that item in the sixth slot
Most players use this trick for Rare Candies or Master Balls because, frankly, if you are going to bend reality, you might as well bend it in style. You can use the SELECT button in the bag to rearrange item order and move your chosen item into slot number six.
Now let’s get to the good part.
How to Duplicate Items in Pokémon Red or Blue: 4 Steps
Step 1: Put the item you want in the sixth bag slot
Open your bag and move the item you want to duplicate into the sixth position. This is the most important setup step, because the glitch affects the quantity of the sixth item specifically. If you put the wrong item there, congratulations, you are about to own an absurd number of something deeply unhelpful.
Good choices include Rare Candy, Master Ball, Nugget, PP Up, Max Elixir, or other hard-to-find items. Less exciting choices include Antidote, Escape Rope, or whatever random junk has been loitering in your inventory since Mt. Moon.
Make sure the amount is under 128. The classic effect of the glitch is to add 128 to the sixth slot. So if you have 1 Rare Candy, the game can bump it up dramatically. If you already have a huge amount, the result may be less useful or display strangely. In a game this old, numbers behave like caffeinated squirrels once they get too big.
Step 2: Watch the Old Man catching tutorial in Viridian City
Head to Viridian City and speak to the Old Man who shows you how to catch Pokémon. This is the gentleman who once blocked your path because apparently coffee was the only thing standing between him and civic responsibility.
Tell him you are not in a hurry, then watch the demonstration where he catches a Weedle. This tutorial temporarily changes how the game stores encounter data, and that is the little crack in the wall that makes the whole trick possible. You do not need to do anything fancy here. Just let the tutorial play out.
Once it ends, do not wander off into random side quests. The setup is active, so your next move matters.
Step 3: Fly to Cinnabar Island and surf along the east coast
Immediately use Fly to travel to Cinnabar Island. From there, move to the narrow strip of shoreline on the island’s eastern edge. This is the famous coast where land and water tiles sit side by side in a way that helps the glitch trigger wild encounters using scrambled data.
Use Surf and move up and down along the coast with your character positioned so that the water is under you and the shoreline is right next to you. This is the classic setup players used for the MissingNo. encounter. Keep surfing until a wild battle begins.
If everything is lined up correctly, you will eventually encounter odd Pokémon, glitch Pokémon, or the legendary star of the show: MissingNo. Depending on your trainer name and some internal values, the exact encounter can vary a little. That is normal. This method is not broken just because the game decides to get creative.
Step 4: Trigger the duplication and check your bag
Once MissingNo. appears, the item duplication effect should kick in. In the classic version of the glitch, the quantity of the item in your sixth bag slot increases by 128. After the encounter, check your bag and look at slot number six. That is where the magic happens.
You usually do not need to catch MissingNo. to get the benefit. In fact, many players prefer not to, because keeping glitch Pokémon around can lead to odd graphics behavior or other side effects. If your goal is simply duplicating items, it is often smarter to admire the chaos, collect your extra loot, and move along.
That is it. Four steps, one coastal surf session, and suddenly your once-rare item stack looks like it got promoted to executive management.
Why This Glitch Works
The short version is that Pokémon Red and Blue store certain bits of data in ways that overlap more than they should. The Old Man tutorial temporarily uses your name data in a special way, and when you later surf along Cinnabar Island’s coast, the game can pull strange encounter information from that corrupted setup. That is why MissingNo. appears.
The item duplication part happens because the game’s internal data for “seen MissingNo.” overlaps with the quantity value for the sixth item slot. When MissingNo. shows up, the bit gets flipped, and the sixth item count jumps. In plain English, the game accidentally rewards you for stepping into one of its weirdest coding potholes.
This is also why the trick became so famous. It feels mysterious when you first see it, but under the hood it is really a data handling mistake with a surprisingly generous payout.
Common Mistakes That Stop the Trick from Working
If the glitch does not work on your first try, do not panic. That is part of the vintage gaming experience. Here are the most common reasons players miss the result:
- The desired item is not in the sixth slot
- You forgot to watch the Old Man tutorial first
- You did not fly straight to Cinnabar after the tutorial
- You are surfing in the wrong place on the island
- You are playing Pokémon Yellow and expecting Red/Blue behavior
Another issue is expecting a perfectly clean, modern-game result. This is a famous Game Boy glitch from the late 1990s. It is a little janky by design. That is half the charm.
Are There Risks?
Yes, but they are usually smaller than the playground rumors made them sound. The biggest commonly reported side effect is that the Hall of Fame data can get scrambled. Some players also notice graphical weirdness, especially if they catch MissingNo. or start experimenting beyond simple item duplication.
That said, the glitch became legendary precisely because many players used it without completely destroying their save files. It has a reputation for being mischievous more than catastrophic. Still, the smartest move is to save before trying it and avoid treating glitch Pokémon like trusted coworkers.
If your only goal is more Rare Candies or Master Balls, keep the process simple. Trigger the encounter, confirm the sixth slot increased, and then get back to regular gameplay like nothing happened. The game may know better, but it cannot prove anything.
Best Items to Duplicate
Not every item deserves duplication. Some are practical, while others are just inventory clutter with a fancy new number attached. Here are the most popular options:
- Rare Candy: Great for fast leveling, especially late in the game
- Master Ball: The overachiever’s dream item
- PP Up: Useful if you want to tune up favorite moves
- Nugget: Easy money once sold
- Max Elixir or Full Restore: Handy for Elite Four prep
Rare Candy is the fan favorite for a reason. One successful duplication session can turn a long grind into a short elevator ride. Whether that improves the game or completely bulldozes its balance depends on your style. Some players want a challenge. Others want a level 100 Blastoise before lunch. Both are valid forms of self-expression.
Final Thoughts
The item duplication trick in Pokémon Red and Blue is one of the most famous glitches in video game history because it is easy to remember, weirdly effective, and wrapped in pure retro legend. It is part cheat, part curiosity, part accidental computer science lesson. And honestly, that is a pretty great recipe for gaming immortality.
If you follow the four-step method carefully, the process is simple: set your sixth item, watch the Old Man, fly to Cinnabar, surf the coast, and let MissingNo. do what MissingNo. does best. Just remember to save first, keep expectations realistic, and maybe do not act too shocked when the game from 1998 behaves like a haunted calculator.
For players who love old-school secrets, this trick is more than a shortcut. It is a tiny time machine. The moment MissingNo. appears, you are not just exploiting a glitch. You are reliving one of gaming’s all-time great myths, except this one actually works.
Experiences With the Pokémon Red and Blue Item Duplication Glitch
There is something wonderfully specific about the experience of using this glitch for the first time. You line everything up carefully, half convinced that the rumor has been exaggerated for dramatic effect. Then you surf up and down the coast of Cinnabar Island, waiting through ordinary encounters and hoping you did not mess up the setup. When MissingNo. finally appears, it feels less like a normal battle and more like the game blinking at you.
That moment has been burned into the memory of a lot of players because it captures what made early Pokémon rumors so powerful. Back then, information spread through friends, cousins, magazines, message boards, and the occasional classmate who spoke with the confidence of a wizard. Some secrets were fake. Some were half-true. But this one was real, and that made it feel magical.
For many players, the first duplicated item was Rare Candy. It was the perfect choice: instantly useful, hard to get in large numbers, and dramatic enough to make you feel like you had broken the economy of Kanto in half. Suddenly, that Dratini you had been raising did not have to wait forever to become Dragonite. The grind vanished. You became the grind.
Other players went straight for Master Balls, which is a wonderfully chaotic decision. There is something hilarious about treating the rarest Poké Ball in the game like a bulk office supply. Need to catch a legendary bird? Master Ball. Found a stubborn Snorlax? Master Ball. Mildly annoyed by a wild Ditto? Entirely unnecessary, but yes, also Master Ball.
What makes the glitch memorable is not just the reward. It is the mood. The music, the weird sprite, the coast of Cinnabar, the sense that the cartridge is revealing a secret it was never supposed to tell. Even the risk adds flavor. You know you are poking at the edges of the game, and that tiny bit of danger makes the success feel bigger.
Today, the duplication glitch still has nostalgic appeal because it represents an era when secrets in games felt personal. You did not just look everything up in seconds. You heard about a trick, tested it, doubted it, then watched it work with your own eyes. That feeling is hard to duplicate, even if the items are easy.
