Chunks are Random

🎲 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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✨ 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**.

🎮 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

🌍 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.

⚡ 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.

📦 Supported versions

Neoforge, Forge, and Fabric, for versions 1.12.x to 1.21.x

📝 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.

❓ 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.