Set up The Abyss 2 on Minecraft

The Abyss II - The Other Side, often called The Abyss 2, is a Forge mod by Y3Z0N. Its CurseForge summary says it adds magic, quests, dimensions, biomes, entities, armour, swords and tools. The core is a dark dimension lit only by glowing plants and fungi. It must be installed on the server and on every player's game.

Checked against The Abyss II - The Other Side 1.0.1 (TATOS 1.0.1 Stable) on Forge 1.20.1, October 2026.

Pick the right server version

The newest stable file is TATOS 1.0.1 for Forge 1.20.1, uploaded to CurseForge on 23 February 2024. A later file, TATOS 1.0.5_beta, tagged for 1.20.1 and 1.20.2, was uploaded on 14 May 2024. The page warns not to use beta versions on servers or existing worlds, so stay on 1.0.1. The beta can show up in the store for a 1.20.1 server, but the Install button takes the newest release before any beta, which is 1.0.1. The jar asks for Forge 47 or newer and for Minecraft 1.20.1 exactly. Older files exist for 1.16.5 (releases) and 1.19.2 (betas).

Open JAR Manager under More, choose Forge under Server software and 1.20.1 under Minecraft version, then press Apply change. The panel picks Java 17 for you. Change your Minecraft version or mod loader has the full steps. Switching reinstalls the server and keeps your world, but make a backup first in the Backups tab.

What it needs

The CurseForge page says the 1.20.1 version requires GeckoLib, JEI and Patchouli. Install GeckoLib and Patchouli on the server. The mod's code uses GeckoLib for its creatures, and its guide book is a Patchouli book. JEI is an item and recipe viewer. Its own Modrinth page lists it as optional on both sides, so a lean server can leave it out. A server with The Abyss II, GeckoLib and Patchouli and no JEI started to Done in our check. Players should install all three.

Install it

1. Open Mods under Content and press the CurseForge chip. The Game version filter starts on your server's version.
2. Search for GeckoLib and press Install, then do the same for Patchouli. Pick the Forge builds for 1.20.1. The store may not offer these for you as a prompt, so install them yourself.
3. Search for The Abyss II and press Install on the result named The Abyss II - The Other Side. Do not pick The Abyss: Legacy, an older project for Minecraft 1.12.2 to 1.16.4.
4. Restart from the Console tab.

The mod's jar is large, about 66 MB as CurseForge shows it. If you upload it by hand, the File Manager accepts files up to 100 MB from the browser, and the mods folder is the place for it. Manage your server files covers uploads.

Open the Installed view afterwards. The three mods should be listed with no Failed to load badge.

Players need it too

Each player installs the same TATOS file plus GeckoLib, Patchouli and JEI for Forge 1.20.1. Join a modded server from your launcher covers the player side, and Fix the mismatched mod channel list error explains the refusal when versions differ.

First steps in the game

The mod includes a guide book called The Abyss: Chapter II. The first entry, "Switching the Reality", explains the Dream Shifter. That item is activated with a right-click and shifts you between realities. The wiki linked from its CurseForge page gives the same right-click and also warns of suffocation after the teleport. The book says to use it in a wide, open area, because the altered world can cause suffocation inside structures or drowning where the sea level has changed. The same entry has the Dream Shifter recipe.

The config can hand the book to each player when they first join. It is the GuideBook setting, described below.

Settings

The mod writes ta_theotherside.toml in the config folder. Stop the server before you edit it in the File Manager. The settings that matter on a server:

• Difficulty: a number from 0 (very easy) to 5 (ultra hardcore). It changes mob strength, spawn rates and how fast infection builds.
• GuideBook: when true, every new player gets the guide book on first join.
• OreRarity: 0 to 30. Zero means very rare veins and 30 means very common.
• StructureGen: 0 to 30. Zero makes dungeons, houses and giant trees rare, and 30 makes them more common.

Common problems

• The server stops at startup: open the Console and read the last lines. A missing GeckoLib or Patchouli is a likely cause. Fix mod and plugin errors on Minecraft covers reading the log.
• The mod is not in the store: make sure the CurseForge chip is selected and the Game version filter is 1.20.1.
• The world has odd bugs: check you did not install a beta file by mistake.