# ๐ฒ Random Chunk Block
**Every chunk you walk into turns into one random block.**
You spawn and the whole chunk around you is oak planks. Walk east and the next chunk is solid TNT.
Keep going: slime blocks, then diamond ore, then bookshelves all the way down to the bottom of the
world. Every new chunk is a surprise, and no two runs are the same.
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## โจ How it works
- The **first time any player enters a chunk** (including the one you spawn in), every block in it
turns into **one single random block**, from the very top of the world down to the bottom.
- **Air, water, lava and chests are left alone**, so oceans, lakes, lava pools and loot chests survive.
- **Chunks you've already visited never change again.** Walk back and forth as much as you like.
This is saved with the world, so it still holds after you quit and reload.
- The random block can be **absolutely any block with collision**: stone, ores, TNT, glass, beds,
barrels, shulker boxes, command blocks, bedrock… Blocks without collision (air, signs, flowers,
torches, portals) are never picked.
- The block list comes from the game itself, so it **only uses blocks that exist in your version**.
Newer versions have a bigger pool (about 780 blocks on 1.20.1), and **blocks from other mods are
included too**.
## ๐ฎ Great for
- Challenge runs: can you beat the game when your spawn chunk is all bedrock… or all TNT?
- Speedrun races with friends
- YouTube and stream chaos
- Just exploring a world that makes no sense
## ๐ Multiplayer and singleplayer
- Works in **singleplayer** and on **dedicated servers**.
- **Server-side only:** players don't need the mod installed to join a server that has it.
- Every player triggers new chunks, and each chunk only ever changes once.
- Works in **every dimension**: the Nether and the End get randomized too.
## โก Lightweight and fast
- Tiny download (under 30 KB, icon included) with **no dependencies**, not even Fabric API.
- When nothing new is being converted, the cost is one quick lookup per player per tick.
- Converting a chunk usually takes **5–20 ms** on modern versions, and around 100 ms at worst.
- Safety features:
- Leaves never decay away.
- Sand and gravel don't pour into the void.
- The server isn't flooded with villager job sites.
## ๐ฆ Supported versions
Neoforge, Forge, and Fabric, for versions 1.12.x to 1.21.x
## ๐ Good to know
- **Normal Minecraft rules still apply after a chunk changes:**
- A farmland chunk collapses into dirt within seconds.
- Buried grass slowly becomes dirt.
- Ice melts near light, and coral dies without water.
- Lava touching water still makes stone.
- **Sand and gravel stay put until something next to them changes,** just like floating sand in a
normal world.
- **Some blocks make heavy chunks.** A chunk full of hoppers, beacons or shulker boxes can be slow to
run or render, because that's tens of thousands of them.
- **Want to reset?** Delete the `randomchunkblock_*.dat` files in your world folder, and every chunk
will randomize again the next time someone enters it.
- **Already-explored worlds work too:** old chunks get randomized the first time you enter them after
installing the mod.
## โ FAQ
**Does it work with other mods?**
Yes. Blocks added by other mods can be picked as the random block too.
**Can I add it to an existing world?**
Yes. Chunks randomize the first time you walk into them after installing.
**Will it crash on a new Minecraft patch?**
No. If a future update ever breaks it, the mod switches itself off with a message in the log
instead of crashing your game.
**Do my friends need it to join my server?**
No, only the server needs it.

