Sky Island WorldGen (Forge 1.20.1)

Start with nothing but a tiny island in an endless void, and build your way up.
This lightweight world generation mod replaces the Overworld with an empty void and places a single hand-made island at the spawn. Choose between three world types, from the classic SkyBlock start to a bigger, lusher island. The End portal is hidden far away, so beating the game is still possible.

✨ Features

• 3 new world types on the Create New World screen (and for dedicated servers):
  • Skyblock Classic: the traditional L-shaped island, 27 blocks per layer and 3 layers deep (grass on top, dirt below), with a single oak tree. The starter chest has an ice block and a lava bucket.
  • Sky Island Medium (20x20): a bigger, natural-looking island with gentle hills, a small mountain, a little pond and a few trees. The chest holds extra saplings, bone meal and seeds.
  • Sky Island Large (40x40): a full island with hills, a mountain, a pond with sugar cane on its shore, 8 trees (oak, birch and spruce), flowers, and pumpkins and melons scattered around. The chest has a composter, 2 villager spawn eggs, saplings, bone meal, seeds, carrots and potatoes.
• Void Overworld: nothing generates outside your island. Limited resources, just like real SkyBlock. Melt the ice with lava, grow trees and farm your way up.
• The End portal is far away: each world gets exactly one portal room, placed in a random direction (based on the world seed) between 2,600 and 3,900 blocks from your island. It’s a small platform with the 12 portal frames, and each frame has a 10% chance of already holding an Eye of Ender. Eyes of Ender and /locate structure skyisland:stronghold point to it.
• Natural-looking islands: irregular edges, tapered undersides, grass, ferns and flower patches. Leaves decay normally, so you can still get saplings and apples.
• Mobs: animals and the usual monsters spawn on your island.
• Nether and End stay vanilla.

  ---

🌌 Recommended with floating-island mods

The mod is built to be used together with a mod that generates floating islands in the Overworld. Your island is the starting point, and the other islands give you more to explore and more immersion. It is meant to coexist with other mods, and a failing feature from another mod is caught instead of crashing world generation.

🔧 Compatibility & Requirements

• Minecraft: 1.20.1
• Loader: Forge 47.x
• Multiplayer: install on both server and clients.
• Dedicated server: set level-type=skyisland\:classic, skyisland\:medium or skyisland\:large in server.properties.

  ---

⚠️ Known incompatibilities

Expanded Ecosphere (default mode): it ships a built-in datapack that replaces the Overworld in every new world, so you will get a normal Overworld instead of the island. To use both mods together, open config/expanded_ecosphere/config.json5 and change "mode": "DEFAULT" to "mode": "COMPATIBLE", or remove Expanded Ecosphere.

The same applies to any mod that overrides the Overworld dimension with a datapack. If your world generates as a normal Overworld, check the mod list for one of those.

❓ FAQ

Can I choose the island size?
Yes. Pick one of the three world types when creating the world.

Does it work in existing worlds?
No. It only affects newly created worlds, because it changes how the world is generated.

Is the End portal always in the same place?
No. It depends on the world seed, so every new world has it in a different direction and at a different distance (2,600–3,900 blocks from your island).

How do I find the End portal?
Throw Eyes of Ender, or use /locate structure skyisland:stronghold in a cheats-enabled world. The portal room floats at about Y=120, so you’ll need to bridge or fly there.

Are vanilla strongholds still generated?
No. In these worlds the portal room replaces them, so there is only one.

My world generated as a normal Overworld. What now?
See Known incompatibilities above. You can confirm the mod is active by pressing F3 in the world: it should show SkyIsland variant: classic (or medium / large).

About

This mod was created by a Brazilian developer (playermatias) who wanted a clean SkyBlock start that works nicely with other world generation mods. Have fun, and good luck on your island! 🏝️