Datapack Codex

Elkonia data packs

The four packs published under elkidog on Modrinth, what each one changes, and which of them can coexist. All four are plain data packs — no mods, no loader — and all three are GPL‑3.0, so you can read them, fork them and learn from them.

📌 Why these are documented here

This reference is mostly about how data packs work in the abstract. These pages are the worked examples: a dimension pack, a whole-Overworld biome replacement, a large jigsaw structure, and a pack that is nothing but attribute modifiers. Where one of them does something the reference explains, the pack page links back to the explanation.

At a glance

PackMinecraftLatestSizeLicence
Elkonian Wilderness26.1, 26.1.1, 26.1.2, 26.21.0.2-blend4,387 KBGPL-3.0-only
Elkonia Deep Coral Ocean Biome1.21.10, 1.21.11, 1.21.9, 26.21.231,085 KBGPL-3.0-only
Elkonia: Phantom Keep26.1.2, 26.226.2.0.9.141,317 KBGPL-3.0-only
Elkonia: Fast Happy Ghasts26.226.2.2.0.210 KBGPL-3.0-or-later

Which one you want

If you want…UseNew world?
A whole custom overworld — new biomes, custom trees, reworked villages Elkonian Wilderness Yes
An all-ocean world with no land at all Deep Coral Ocean Yes
A rare dungeon to find in an otherwise normal world Phantom Keep No — drops into an existing save
Faster happy ghasts, with the harness colour as a throttle Fast Happy Ghasts No — drops into an existing save
⚠ Two of the four cannot be combined

Elkonian Wilderness and Deep Coral Ocean both replace the Overworld generator, so they conflict with each other and with any other worldgen pack in the same save. Worse, a data pack that defines world generation is baked at world creation — adding it to an existing world does nothing to terrain that already exists, and removing it from a world that used it leaves chunks that can no longer be generated consistently. Decide before you create the world, not after.

Phantom Keep adds a structure rather than a generator, so it layers onto an existing world happily — though only chunks generated after you add it can contain a keep.

Installing any of them

  1. Download the .zip from the pack's Modrinth versions page.
  2. Drop it into <world>/datapacks/ — or a server's world/datapacks/. Do not unzip it.
  3. For the two worldgen packs, do this before the world is first loaded.
  4. /datapack list in game to confirm it is enabled.

Some of these ship a resource pack alongside the data pack for their custom textures. The data pack is what generates the world; the resource pack only changes how it looks, and the world is still playable without it.

Reading them as examples

All four are GPL‑3.0 and unobfuscated JSON, so the fastest way to learn a technique is often to open the one that already uses it:

To see how…OpenAnd read
a custom dimension and biome set is wired up Elkonian Wilderness Dimensions, Biomes
one biome is forced across an entire Overworld Deep Coral Ocean Worldgen
a large structure is assembled from jigsaw pools Phantom Keep Template pools
attributes are layered without compounding, and a loop is avoided Fast Happy Ghasts Data components, Advancements
custom trees and placed features are defined Elkonian Wilderness Features

Sources