Shared code library
The common systems Shadows_of_Fire's mods rely on, kept in one place.
Minecraft library mod
Placebo Mod - the library behind Apotheosis
Placebo Mod by Shadows_of_Fire is a code library for Minecraft Forge and NeoForge. It adds nothing to your world by itself — but Apotheosis, Gateways to Eternity and other popular mods won't load without it.
Placebo mod download
How to install
9.9.41.21.1 build
1.12.2+Versions
MITFree
Placebo
Library I
Author: Shadows_of_Fire
1.21.1: 9.9.4 (MC 1.21.1)
Loaders: Forge · NeoForge
+ Loads Apotheosis & friends
+ Fixes "missing placebo"
placebo:library
What is Placebo Mod?
A library mod, not a content mod
Placebo holds code that several of Shadows_of_Fire's mods share. You install it for one reason: a mod you want needs it.
Advancement Made!
Why “Placebo”?
Like its name, it has no visible effect. No blocks, items or menus — just shared code.
Advancement Made!
Shared code
Common systems live in one library, so each mod that uses it stays smaller and easier to update.
Goal Reached!
Mods launch
With the matching Placebo build installed, Apotheosis and its sibling mods start without errors.
Required by
Mods that need Placebo
These popular mods by Shadows_of_Fire list Placebo as a required dependency. Hover a slot to see what each one does.
Features
Small library, big enchantments
Everything worth knowing about Placebo Mod at a glance.
Tiny and invisible
No new blocks, items or menus — just a small .jar that other mods load.
Forge & NeoForge
Forge builds up to 1.20.1, NeoForge builds for 1.21.1 and the new 26.x versions.
Since 1.12.2
Releases go all the way back to 1.12.2, so classic modpacks are covered too.
Free & open
Released under the MIT licence with its source code on GitHub.
Client & server
Install it on the server too whenever the mods that need it run there.
Placebo mod download
Select your version
Pick your Minecraft version from the list, just like choosing a server. The panel shows the exact Placebo build, loader and download.
Placebo mod Fabric · Bedrock
Incompatible editions
Two searches come up a lot. Here's the straight answer before you download anything.
Fabric: incompatible
Placebo is made for Forge and NeoForge only. If a Fabric mod asks for “Placebo”, you probably downloaded the Forge version of that mod — or switch your modpack to Forge/NeoForge.
Bedrock: incompatible
Bedrock, Minecraft PE and console editions can't load .jar mods, and no Bedrock version of Placebo exists. Files claiming otherwise are not this mod.
Installation
Level up in six steps
Works the same for Forge and NeoForge, on any Minecraft version Placebo supports.
1
Check setup
Note your Minecraft version and loader.
2
Install loader
Run the Forge or NeoForge installer.
3
Get Placebo
Pick the matching build above.
4
Add the mod
e.g. Apotheosis, matching Minecraft and loader.
5
Drop in /mods
Use the active launcher instance and its mods folder.
6
Play
Launch with your Forge/NeoForge profile.
How it works
One dependency, shared foundations
Placebo supplies reusable code to dependent mods. The gameplay comes from those mods; Placebo provides part of the foundation they expect to find.
The loader discovers your mods
Forge or NeoForge reads the mod files in the active instance and checks their declared dependencies before gameplay starts.
Required versions are checked
If a mod requires Placebo, a compatible build must be present. Matching Minecraft alone is insufficient: check the loader and the dependency version range too.
Dependent mods use the library
Once the requirements are satisfied, mods can use the shared code. Placebo alone does not add a gameplay experience or guarantee that an otherwise incompatible pack will launch.
Use cases
When should you install Placebo?
Playing a dependent mod
Install it when the chosen release of a mod such as Apotheosis declares Placebo as required. Follow that release's dependency list rather than assuming every historical version has the same requirements.
Building or maintaining a modpack
Keep a tested combination of Minecraft, loader, Placebo and dependent mods. Respect the pack's pinned versions and test updates in a separate instance before distributing them.
Running a multiplayer server
Add Placebo to the server instance when a server-side mod requires it. Give players the matching pack, including required client dependencies, and restart the server after changes.
Installing Placebo by itself is not a way to add new mobs, recipes or FPS improvements. Install it to satisfy an actual dependency.
Compatibility / comparison
Match the platform before the download
| Platform | Placebo support | What to check |
|---|---|---|
| Java + Forge | Version-specific builds | Select a file explicitly tagged for your Minecraft and Forge versions. |
| Java + NeoForge | Version-specific builds | Use the matching NeoForge release; do not assume a Forge file is interchangeable. |
| Java + Fabric / Quilt | No official build listed | Forge and NeoForge jars cannot simply be placed in a Fabric or Quilt pack. |
| Bedrock / mobile / console | Not supported | These editions do not use Java Edition mod-loader jars. |
| Vanilla Java | Loader required | Install the appropriate loader first; vanilla cannot load Placebo directly. |
Placebo vs a content mod or another library
A content mod supplies gameplay; Placebo supplies shared code. Other libraries are separate dependencies and cannot replace it just because they also provide APIs. Keep every library requested by your chosen mod releases.
Check supported loaders and individual file tags on the official Placebo files page.
System requirements
Your modpack sets the hardware needs
There is no separate CPU, GPU or RAM minimum published on the Placebo project overview. Size your setup for Minecraft and the entire modpack rather than treating a library's small download as a hardware benchmark.
- Game edition
- Minecraft Java Edition, using a version supported by the selected Placebo file.
- Mod loader
- The Forge or NeoForge version required by the file and the rest of your pack.
- Java runtime
- Use the Java runtime required by your Minecraft and loader release. Check the launcher profile's runtime instead of installing an arbitrary newer Java version.
- Memory and storage
- Follow the modpack author's memory guidance. Allow room for mods, world saves, backups and logs; Placebo alone does not determine RAM allocation.
- Operating system
- A system capable of running the chosen Minecraft Java and loader combination. Instance paths differ between Windows, macOS, Linux and launchers.
Troubleshooting
Find the cause before changing files
Missing Placebo dependency
Read the requested version range in the loader's message. Download a matching main jar and place it in the active instance's mods folder, then restart the game.
Wrong version or loader
Compare Minecraft, loader and Placebo file tags. A file for a different Minecraft release or loader may fail even if its Placebo version number is higher.
Duplicate mod detected
Close the game and keep one compatible Placebo main jar in the instance. Move older duplicates out of mods; source jars are for development, not normal play.
Crash after an update
Restore the previous tested combination from a backup, then review logs/latest.log and any crash report. Change one dependency at a time in a test instance.
Server refuses to start
Check the server's own mods folder and startup log. Installing a dependency on your client does not install it on a remote server.
Still cannot identify the issue?
Record the exact Minecraft, loader and mod versions, reproduction steps and relevant log excerpt. Remove personal information before sharing logs through the project's support channel.
An exit code alone rarely identifies the failing mod. Read the dependency message or first relevant exception; a library mentioned in a stack trace is not automatically the root cause.
Safety
Download carefully, update with a backup
- Start with the author's project. Use Placebo on CurseForge and check the author, Minecraft version, loader and file details before downloading.
- Choose the normal mod jar. You do not need an unrelated downloader, browser extension or a sources jar to play. Place the mod jar in your instance; it is not a standalone installer.
- Keep backups. Copy your worlds, configs and working mod list before changing a pack. Try updates in a separate instance first.
- Review what you run. Mods execute code on your computer. An official source reduces impersonation risk, but no source or antivirus scan guarantees a file is risk-free.
The author's source repository is available for inspection. This site is an independent guide.
Pros and cons
Useful infrastructure, with version constraints
Pros
- Satisfies a required dependency for supported mod releases.
- Centralizes reusable code instead of repeating it across dependent mods.
- Free, with source code available under the MIT license.
- Offers releases across multiple Minecraft generations for compatible packs.
Limitations
- Adds no standalone gameplay content.
- Requires the correct Minecraft, loader and dependency versions.
- Official files target Forge and NeoForge rather than Fabric or Bedrock.
- Updates need pack testing; installing the newest file is not always the correct choice.
FAQs
Your Placebo questions, answered
Basics
What does Placebo Mod do?
It holds shared code used by dependent mods. By itself it registers as a mod without adding visible gameplay content.
Who develops Placebo?
Placebo is published by Shadows_of_Fire. Use the author-linked project and source repository to identify the intended library.
Do I need it for every Minecraft mod?
No. Install it when a specific mod release or modpack lists Placebo as a required dependency.
Does Placebo add blocks, mobs or items?
No standalone gameplay content is added by Placebo itself. Such changes come from the content mods that use it.
Will installing Placebo increase my FPS?
Placebo is a dependency library, not a standalone FPS optimization tool. Performance depends on the whole pack, settings and hardware.
Is Placebo free and open source?
Yes. The project lists an MIT license and links its source code on GitHub. Review the license when redistributing or modifying it.
Can another library replace Placebo?
No. Libraries provide different APIs. If a mod declares Placebo as required, install a compatible Placebo release even when other libraries are already present.
Installation & Compatibility
How do I choose the right Placebo file?
Match the exact Minecraft release, the loader tag and the version range required by dependent mods. Follow pinned modpack versions when provided.
Where do I put the downloaded jar?
Use the mods folder inside the active launcher instance. Custom launchers often use a separate directory from the default .minecraft folder; open the instance folder from your launcher.
Should I extract or double-click the jar?
No. Keep the normal mod jar intact and put it in the mods folder. Start Minecraft through the matching Forge or NeoForge profile.
Does Placebo work with Fabric or Quilt?
The official project lists Forge and NeoForge builds. Do not assume those files will work in Fabric or Quilt; use a pack built for a supported loader.
Can I install Placebo on Bedrock or mobile?
This Placebo project is a Java Edition mod. Bedrock, mobile Bedrock and console editions do not load these Java mod-loader jars.
Do I need Placebo on a dedicated server?
Install it in the server instance if server-side mods require it, and include it in player packs where required. Check the dependencies on both sides.
Can a newer Placebo release work on older Minecraft?
Only when the file explicitly supports that Minecraft version and your required loader. A higher Placebo version number does not imply backward compatibility.
Troubleshooting & Safety
Why does the loader say missing placebo?
A loaded mod requires Placebo and cannot find a compatible copy. Check the requested version range, install the correct main jar in the active instance and restart.
What should I do about a duplicate mod error?
Close the game and move obsolete Placebo jars out of the active mods folder. Keep one compatible main jar rather than several versions or sources jars.
Why does Minecraft crash after I update Placebo?
The new file may not fit the Minecraft, loader or dependent mod versions. Restore your tested backup and inspect latest.log or the crash report before updating one component at a time.
Is Placebo safe to download?
Get it from the author-linked project and check the file details. Mods execute code, so no download can be guaranteed risk-free; avoid unrelated installers and keep backups.
How much RAM does Placebo need?
The project overview does not publish a separate RAM minimum for this library. Use the requirements of Minecraft and your full modpack to decide memory allocation.
Can I remove Placebo from an existing pack?
Only after checking that no remaining mod requires it. Back up the instance first; removing a required library prevents dependent mods from loading.
What information helps when reporting a problem?
Include exact Minecraft, loader, Placebo and dependent mod versions, steps to reproduce, and the relevant log or crash report. Remove personal information before sharing.