Mods/Cheating

Hacking is altering software in order to make it work in a way not originally intended. This is not be confused with 'Cracking' or Black Hat hacking - the process of defeating of security devices in computer networks or software copy protection. For more on the difference between types of hacking, see this article.

In Minecraft, hacking refers to using a memory editor in order to alter the variables which the Minecraft Java runtime, or standalone application is storing on your computer. This allows you to do virtually anything, including access blocks not usually available (such as a Mob Spawner).

Note: The architecture of Linux/Unix systems mean that memory editors cannot work on them, restricting this practice to Windows clients only.

Alpha

 * 1) Open Minecraft and start a new game or load a saved game.
 * 2) Open Cheat engine.
 * 3) Select process 'javaw.exe' near the bottom.
 * 4) Get at least 3 of some block type in your quick slot.
 * 5) In cheat engine, start a new search and search for that item
 * 6) Drop an item (Q).
 * 7) Search for the new value.
 * 8) Drop another (or pickup the old one, doesn't matter).
 * 9) Search for the new value You should only have a few now. Repeat until you only have ONE entry.
 * 10) Double click to add entry.
 * 11) In bottom pane of cheat engine, right click and choose 'Browse this memory region'.
 * 12) Exactly 8 bytes to the right of the block's quantity is the block's TYPE. Compare with the hex values found here
 * 13) To change the type, copy the DECIMAL value from the data values page, double click on the type in the memory viewer, select 2 bytes, and paste. You can do this for items (e.g. Ingots) as well as blocks

Here is a video going through the process

Classic

 * 1) Pull out Cheat engine or another memory editor.
 * 2) From the PROCESSES List, select 'java.exe' or 'javaw.exe' (Please note: If you have downloaded the standalone, select 'Minecraft.exe' from the list instead.)
 * 3) In minecraft, make sure you have the first block in your UI as stone.
 * 4) Scan for the exact value 1
 * 5) Go to minecraft and change the first block in the UI to cobblestone.
 * 6) Scan for the exact value 4
 * 7) Go to minecraft and change the first block back to stone
 * 8) Repeat step 4
 * 9) This should yield one or two addresses. Pick one (or both) and change the value to one of the following material values from this list.

Health
Even with peaceful mode set, it is easy to fall into lava and die, losing all your hard earned ores in the process. Luckily, it is very easy to hack your health to become truly invulnerable.

Method

 * 1) Open Minecraft.
 * 2) Open Cheat Engine and select javaw.exe.
 * 3) Get your number of hearts, and double it, adding one if you have a half heart (full hearts = 20), and start a new search in CE with this value.
 * 4) Get hurt a bit, or heal a bit, and recalculated your HP. Enter this value for the next search.
 * 5) Repeat until one value remains. Double click to add.
 * 6) Either set to a very high value, or set to 20 and freeze.
 * 7) Enjoy invulnerability.

Here is a video going through the process

NOTE: If you freeze your value, do not enter/leave The Nether, this will move the address where you HP is stored, possibly leading to data corruption and crashed games. Also, you won't be invulnerable again. You can re do the above hack WHILE in The Nether, though, and it works fine.

Consequences
Trying to do this can result you in getting banned/kick/ipbanned in multiplayer servers, though the server will know when you're cheating/hacking. It will display "Cheat detected: Tile type" and will reset everything back to normal, so it only works in Single player. It should be noted that hacking is only appropriate in single player mode, and attempting it on a multiplayer server can result in the software kicking you from the server.

Cube of destruction (CoD)
A cube of destruction is actually a 2*2*2 cube of tnt, that has been frozen on the TNT state and will never change back to air until MC changes block addresses.
 * 1) Open minecraft and load/start a new game.
 * 2) Collect a few of any block type.
 * 3) Open Cheat Engine and select javaw.exe at the bottom of the process list.
 * 4) Search for the number of block you have.
 * 5) Drop an item (Q).
 * 6) Return to CE, and type in the new value, then 'next scan'.
 * 7) Get/drop another item and scan again with the new value.
 * 8) When there's only one item in the list, double click to add it.
 * 9) Right click and click 'Browse this memory region'.
 * 10) Increase the first byte by double click and setting to 64.
 * 11) Double click the ninth byte and set to 86 (Pumpkin).
 * 12) Place the pumpkin where you want the Cube of Destruction.
 * 13) Start a new search for value 86 value type 'byte'.
 * 14) Destroy the pumpkin.
 * 15) Search again for value 0.
 * 16) Repeat placing, filtering for 86, destroying, and filtering for 0 until only one item is on the list, then double click to add to the list.
 * 17) Place another pumpkin next to the first, and start a new scan, repeating again as above for 86, 0, 86
 * 18) Continue until you have a 2x2x2 cube
 * 19) Set the last 8 values to 46, and then freeze
 * 20) In game, whack a few of the TNT and run.
 * 21) You will die. Before respawning, un-freeze the values, and respawn to see the damage.

Note: You can lower the time of the process by searching for block layers. Example: Scan for 3, remove a layer of blocks and scan for 0, continue doing this and adding new layers. Each layer you add you have to start a new scan. Such method is useful for making big CoDs like 3*3*3.

There is a video showing the process here.