Tutorials/Block and item duplication

This page seeks to teach you how to clone items and blocks without building a separate farm for them, in vanilla Survival mode. It can be treated as an "everything farm," since it can "farm" things that can't normally be farmed, like diamonds and dragon eggs.

Note that these techniques are considered "cheating" by many people and Mojang tries to remove the ability to duplicate in Survival during almost every update. On some servers, these techniques are bannable offenses.

The best way to duplicate a block is to turn it into an item first, then duplicate the item. However, there are other ways to duplicate the blocks themselves, though they only work for certain blocks. Shulker boxes make item duplication much easier because they allow for up to 1,729 items to be cloned at once (including the shulker box).

Why Bother?
Duplicating items and blocks can be very useful. For example, let's say you wanted to obtain enormous amounts of glass or sand. Going into a desert and mining it yourself is extremely time-consuming, so a sand duplicator can be very useful.

If you wanted to break a lot of bedrock using this technique, the player can build a dragon egg duplicator to create more dragon eggs.

Deadly Method
This method is extremely deadly, but not necessarily to the player. This method involves taking a mob that can carry items (such as a zombie, a donkey or a llama) down to very low health, as in a quarter of a heart or less. Using extremely precise timing, kill that mob as it travels through an end portal. The items equipped and the mob should appear in the other dimension. It works by tricking the game into thinking the mob is alive on one end of the portal and dead on the other side. The live mob will travel through the portal still carrying the items, and the dead mob's items are also sent into the portal, allowing the player at the other end to collect the cloned items and the mob carrying them.

Zombie/Drowned Method (Patched)
This method exploits the fact that zombies can transform into drowned while they are dying. If you coax a zombie to pick up an item by throwing one at it and then kill it right at the moment that it converts to a drowned, the zombie will die and drop what it was holding but the newly spawned drowned will be holding a duplicate of the item. This can also work with husks transforming into zombies.

This was originally discovered by Cycryl:

Ilmango shows a simple implementation for survival:

Perfect Timing
There are numerous timing-related ways to duplicate items. Most of these are only possible in singleplayer since you have the ability to pause the game and log out at any time.

Dropped Items
When you drop items and then relog at exactly the same time that you pick them up, you can duplicate what you dropped.

Piston Duplication (patched)
When an item frame is removed (broken by the player) from the rear of a piston as the piston is retracting, the correct timing will yield two items of the item that was within the frame. This will work with any blocks or items inside of the frame, with shulker boxes being able to duplicate multiple items at once. This method works in both singleplayer and multiplayer game modes.

Multiplayer-Exclusive
This requires a multiplayer or LAN server. There are two variations to this method.

Same Player Twice (patched since 1.14)
There is a way to trick the game into logging in the same player twice on one server. To do this, start two instances of Minecraft. This requires starting a new instance of the Launcher so that they don’t interfere with each other. Log them both on the same server at the same time. By doing this, the game will render two of the same player. You can then kill the copied player and double your inventory.

Player Data Editing
This requires two different players and access to the server files. The server stores the contents of the inventory as separate files for each player. All you have to do is replace the inventory data of one player with the inventory data of another player. It is best if the receiver of this has an empty inventory.

Rail Duplication
This can be accomplished by moving rails in such a way that it is both pushed and dropped as an item. This happens because before pushing, the piston creates a list of the blocks it is about to push. Then, the blocks underneath the rails are moved first, causing the rails to pop off as items; then the piston moves the rails from the list of blocks it created previously, placing the rails in the world.

TNT Duplication
TNT duplication works in a similar way as rail duplication. A TNT block is BUD-powered, such that when the contraption is pushed by a piston, the TNT is updated and ignites into a primed TNT entity. Then, the piston moves the TNT from the list of TNT block left.

Gravity Block Duplication
There are many ways to do this, but the basic idea is the same.

A gravity-affected block is pushed toward an end portal. It becomes an entity as it falls into the portal, and it travels into the other dimension's "spawn point.", but before it's removed from the original dimension, it bounces off an entity in the portal (in a vehicle so it won't go through), and is caught by some pistons. It then turns into a block and is returned to its original location. This process can be looped using redstone. It works for any block that is affected by gravity, except for primed TNT because it would blow up the contraption.

Dirt Duplication
Dirt duplication relies on the crafting recipe for coarse dirt. Coarse dirt is crafted with 2 dirt blocks and 2 gravel blocks and the player gets 4 coarse dirt from it. If the player hoes the coarse dirt, it becomes normal dirt. Some of this new dirt created can go into crafting more coarse dirt. You can continue this process infinitely, as long as you built a gravel duplicator using the method above.

Lead Duplication
Bring an animal to the end, put a lead on it, and then lead it into the end portal. When you get back, it should have dropped two leads. Sometimes one of the leads ends up in the end, so make sure to check there. This also works when bringing animals into the end.

Piston Chest (Versions 1.5.1-1.7.1+)
(Duplicates all Items)

When a chest is pushed by a piston, the contents are backed up a split second before it is moved. If you are in the chest interface and quick-move an item to your inventory in that moment then you will receive the item and the chest will be moved with the item still in it as well.

The recommended build is not automatic (but that certainly can be done ). You need at least 1 switch, 2 pistons/1sticky piston, 1 chest, 10 redstone repeaters (all set to maximum delay), 2 redstone dust, and 1 button; this allows a setup where you can stand in the middle of a curved path of redstone from the button to the piston that will push the chest without you having to do more than turn around after hitting the button to open the chest and put the cursor over the item to duplicate (make sure to be angled so you can see the last 3 redstone repeaters outside the chest interface). The timing to move the item is just before the redstone signal moves to the final redstone repeater. It will take a bit of practice to get it right, but is pretty easy to do. The switch is to be next to the second piston, placed so it will push the Chest back into place.
 * This method makes mass-duplication possible with the use of a shulker box and moving the contents of one duplicated box to the other, thus doubling how much you get each time, until you are duplicating an entire box's worth of items.
 * This does run the risk of massive lag in your world, by creating too many shulker boxes with contents. The effect may be even greater in online worlds such as realm servers. Be sure to transfer most items to regular chests after duplicating to avoid this.

Rapid Dispenser (Versions 1.5.1-1.5.2+)
(Duplicates some Stackable Items only)

This video will explain how to duplicate any ore using a dispenser and a redstone clock.

Bed Duplication
Due to how beds are made out of 2 blocks, an explosion near the bed can make the bed drop 2 bed items, meaning you can spawn 2 beds (4 bed blocks) when you had 1 (2 bed blocks). You can repeat this and get infinite beds.

Patched Methods (Bedrock Edition)
To use the following methods, you will have to either not update past that point or revert to a previous update (if possible for your system, not all can, such as on Xbox One or Nintendo Switch).

Anvil Naming (Versions 1.5.1-1.5.2)
(Duplicates any Stackable Items only) '''Patched in 1.5.3, by removing the "Take Half" option from the Anvil output options. When naming a stack of items in an anvil, you can use the "Take Half" option to receive the output items without depleting the original stack. As long as you do not take the final re-named item, you can go to the original stack and pick it up to start more or just leave the anvil interface if you are done. Items duplicated this way won't work for quick use in a recipe, though certainly can be used for Classic crafting and any other use. However, if you wish to revert an item to the default name, you can do so by crafting it into another item then crafting it back to the original (such as redstone block -> redstone dust x9 -> redstone block), or by placing it as a block then breaking it back into an item.
 * A way to speed this up is to hit "Take Half", then "Toss Item" while standing close to the anvil, so you can rapidly go through a full stack without having to manually move each selection.
 * Sometimes a block won't lose it's name when broken into an item, such as shulker boxes which are meant to keep their name, or just randomly the name may stay with a regular block and repeating the process will remove the name. However, some items may break into different items, such as an ender chest dropping obsidian, and the obsidian will each retain the ender chest's name (this was likely a glitch).

Resetting Nether or the End
By resetting Nether or the End continuously, Nether and the End block and items can be duplicated.

Pick Block Trick
The pick block trick makes use of the button 'pick block'. As it is unassigned by default, the player must go into the settings and assign it to a button. The player must then procure two blocks of the item being duplicated. The player must place one on the ground, and one in their inventory not in their hotbar. The player must leave two spaces in their hotbar. The player then presses the 'pick block' and 'change holding item' (R1 or L1 on PS4) buttons at the same time. The player then must turn all of the duplicated blocks back into their subparts (iron blocks back to iron ingots, slime blocks back to slime balls etc.) N.B. The player MUST use their own crafting grid, not a crafting table to revert the blocks or the duplication will fail.

Duplicatable items are limited to:

 * Iron Ingot
 * Gold Ingot
 * Diamond
 * Emerald
 * Slimeball
 * Cobweb
 * Coal
 * Redstone Dust
 * Lapis Lazuli
 * Hay Bale
 * Bone
 * Melon

教程/方块和物品复制