Palworld server mods: UE4SS and pak mods

Palworld has no official mod loader, so server mods run on community tools. There are two kinds. Pak mods are Unreal asset files dropped into Pal/Content/Paks/~mods/; they change data and assets and need no loader. Script mods are Lua (or C++) mods run by UE4SS, an Unreal Engine scripting system installed into Pal/Binaries/Win64/; they change behaviour at runtime. UE4SS is built for Windows, so script mods on a server realistically mean the Windows server build - natively, or under Wine on Linux. The question that decides everything else is where a mod has to be installed: on the server only, on clients only, or on both. Get that right and a modded Palworld server is manageable. Get it wrong and players are kicked on join or see a world that does not match the server's.

Setting up the server itself is covered in Palworld server settings, and a surprising number of things people install mods for are already settings there - rates, stack weight, base limits. Check that first. Every mod you do not install is one that cannot break on patch day.

The two kinds of Palworld mod#

Pak mods are the oldest and simplest form. Unreal loads every .pak it finds in the game's pak folders, and a pak in ~mods is loaded after the game's own, so it overrides what it contains. A pak can replace a data table (pal stats, item recipes, drop rates) or an asset (a model, a texture). Pak mods do not run code.

UE4SS - the community project RE-UE4SS - injects into the game process and gives mods a Lua scripting API, hooks into game functions, and a loader for blueprint mods. Most mods that change how the server behaves rather than what its data says are UE4SS mods. Palworld support has historically needed a UE4SS build that knows Palworld's version; the mod pages say which build they expect.

Server-side, client-side or both#

Every mod falls into one of three groups, and you need to know which before you install it.

• Server-side only. The server is authoritative for most of the game: spawning, drops, damage, pal behaviour at bases, player data. A mod that changes those things through script can run only on the server, and players need nothing. Admin tools, logging, Discord bridges, server-side protection tools and many rule tweaks belong here.
• Client-side only. Interface changes, visual replacements, camera and quality-of-life mods that only affect what one player sees. The server is not involved; players install them on their own PC and the server does not care.
• Both. Mods that add new content - new pals, new items, new structures - or that change data the client also reads. If the client does not have the mod, it does not know what the server is talking about. Depending on the mod, a player without it sees missing models, cannot interact with the new thing, or crashes.

The mod page usually says. When it does not, treat any mod that adds content as "both" and any mod that only changes numbers the server calculates as worth trying server-side first.

Data-table pak mods are the grey zone. If the server is authoritative for a value - a drop rate, a work speed - the server's copy of the table is the one that matters. If the client also displays or predicts the value, a client without the mod shows the old number while the server uses the new one. It works, but it confuses people. For anything players will notice, require the same pak on both sides.

Installing UE4SS on a Windows server#

The Windows dedicated server's binary lives in Pal/Binaries/Win64/. UE4SS installs there, next to it.

1. Stop the server and take a backup of the world folder.
2. Download a UE4SS release that supports your Palworld version. Newer UE4SS releases ship as a dwmapi.dll proxy plus a ue4ss folder; older ones as UE4SS.dll with settings and a Mods folder alongside. Follow the layout of the release you download - do not mix files from two versions.
3. Extract it into Pal/Binaries/Win64/.
4. Start the server once. UE4SS writes a log file (UE4SS.log) in its folder. If the log shows UE4SS initialising and finding the game's functions, it is working.
5. Stop the server again before adding mods.

A typical layout after installing a recent release:

Pal/Binaries/Win64/    PalServer-Win64-Shipping-Cmd.exe    dwmapi.dll    ue4ss/        UE4SS.dll        UE4SS-settings.ini        UE4SS.log        Mods/            mods.txt            BPModLoaderMod/            SomeLuaMod/                Scripts/main.lua                enabled.txt

UE4SS settings live in UE4SS-settings.ini. On a headless server, turn off anything to do with the GUI console or debug windows; there is nobody to see them and they can cause trouble on a machine without a display.

Installing mods#

Lua mods are folders. Each goes into UE4SS's Mods/ folder with its Scripts/main.lua inside. A mod is enabled by an enabled.txt file in its folder, or by a line in Mods/mods.txt:

BPModLoaderMod : 1SomeLuaMod : 1AnotherMod : 0

1 loads the mod, 0 skips it. The built-in mods UE4SS ships with, such as BPModLoaderMod, should stay enabled if you use blueprint mods; it is what loads them.

Blueprint mods are paks that go into Pal/Content/Paks/LogicMods/ (create the folder if it is missing). They are loaded by UE4SS's blueprint loader, so they do nothing without UE4SS.

Pak mods go into Pal/Content/Paks/~mods/ (create it if missing). The tilde makes the folder sort after the game's own paks, which is what gives mods priority. When two pak mods change the same asset, the one that loads last wins; some mod authors name their files with a number or letter prefix to control order. Mod load order explained covers the general idea.

Upload all of these through the file manager or SFTP - SFTP and the file manager has the details - and add one mod at a time. Start the server after each, check the log, play for a bit, then add the next. When something breaks, the cause is the last thing you added.

Mods for Palworld are mostly published on Nexus Mods, with installation notes on each page. Read the requirements section: many mods depend on a specific UE4SS version or on another mod such as a shared library or a data-editing framework.

Linux servers#

The official Linux dedicated server is the efficient way to run vanilla Palworld, and it is a poor fit for script mods. UE4SS is developed for Windows. It has had experimental Linux efforts, but in practice:

• Pak mods may load on the Linux server, depending on how they were built. Test each one.
• UE4SS, Lua and blueprint mods generally mean running the Windows server build instead. On a Linux machine that means running the Windows build under Wine or Proton, which works for many people and costs extra memory and some stability. Wine and Proton for Windows-only servers covers the trade-offs.
• Native DLL mods are Windows only.

If a server is going to be modded beyond a few pak files, decide on the Windows build at the start rather than migrating later. The world save is the same format either way, so moving is possible; it is just one more thing to do on a day you would rather be playing.

What mods cost#

Most Palworld mods are cheap. A Lua script that adjusts a value when a pal is captured costs nothing measurable. The ones that cost are the ones that change how much the world holds:

• Raising base and pal limits beyond what PalWorldSettings.ini allows. More working pals is more simulation and more memory; the Palworld performance and base limits post explains why pals, not players, are the cost.
• Mods that add many spawns or new pals that roam the world.
• Mods that keep extra data per player and write it on every save.
• UE4SS itself under Wine, which adds overhead before any mod runs.

Watch the memory graph for a few days after a new content mod. A mod that adds a slow climb shows up across days, not minutes.

Game updates break mods#

This is the part of running a modded Palworld server that takes the most time. UE4SS finds the game's functions by looking for patterns in the executable. A game update moves those, and until UE4SS (and each mod) is updated, the server may fail to start, start without mods, or crash when a mod calls something that is no longer where it was. Pak mods that replace data tables break when the game changes the table's layout.

A defensive routine:

1. Turn off automatic updates on a modded server, if your setup allows. Update deliberately.
2. Before updating the game, check the UE4SS and mod pages for versions that support the new build.
3. Back up the world and the whole `Pal/Binaries/Win64/` folder before updating, so you can put the old mod setup back.
4. After updating, start once with mods disabled (rename Mods/mods.txt entries to 0 or move ~mods aside) to confirm the vanilla server and world load. Then enable mods one at a time.
5. Players must update their client mods too, for any mod that is installed on both sides. Tell them which version.

The general procedure for the morning after a breaking update is in what to do when a mod update breaks.

Keeping a modded server safe#

Mods are code running in your server's process. A UE4SS or DLL mod can do anything the server can: read files, change saves, open network connections. Download from the mod's real page, prefer mods with source available or a long track record, and be suspicious of a "fixed" or "unlocked" version of a mod re-uploaded by someone else. Keeping a modded server clean has the checklist.

Server-side protection and admin tools are among the most useful server-only mods for a public server. PalDefender (previously known as PalGuard) is the best known; it runs on the Windows server and adds checks against common cheats plus admin features. Read its documentation for the version it supports.

Mods on RE:NODE#

On RE:NODE, mods are uploaded by you through the in-browser file manager - which unpacks archives in place, so a UE4SS release zip can be dropped in and extracted - or over SFTP. There is no allow list and no one-click mod installer; you choose the mods and their versions. What a panel cannot change is which server build the install runs, and the Linux limits above apply to any Linux-based install - if your plans depend on UE4SS script mods, check which build your server runs before you build a mod list around it, and ask support if the files do not make it obvious. Palworld plans start from 8 GB, and backup slots on every plan cover the back-up-before-patch-day step. If a mod crashes the server repeatedly, the crash watcher raises a warning and opens a ticket after three restarts in an hour, which is usually the first sign that a mod did not survive an update.

Troubleshooting#

The server starts but no Lua mods run. UE4SS did not load. Check that its files are in Pal/Binaries/Win64/ next to the server executable and that UE4SS.log exists and shows initialisation. On a Linux build, UE4SS will not load at all.

UE4SS loads and then the server crashes. A UE4SS build that does not support this game version. Update UE4SS, or remove it until a supported build exists.

Blueprint mods do nothing. BPModLoaderMod is disabled, or the paks are in ~mods instead of LogicMods.

Players crash or see missing models. They lack a mod that must be installed on both sides, or have a different version.

A pak mod's changes do not apply. Another pak loaded later overrides the same asset, or the game changed the data table and the mod is outdated.

Everything broke after a game update. Expected. Start vanilla, then reintroduce mods one at a time as they are updated.

FAQ#

Does a Palworld dedicated server support mods officially?

No. Mods run on community tools: pak files loaded by the engine and UE4SS for scripts and blueprint mods. Check the game's patch notes for changes, as official support has been discussed but is not what servers rely on today.

Do players need the same mods as the server?

Only for mods that add content or that the client must know about. Server-side mods such as admin tools and many rule changes need nothing on the client.

Can I run UE4SS on a Linux Palworld server?

Not reliably. UE4SS is built for Windows. Modded servers usually run the Windows server build, either on Windows or under Wine on Linux.

Can Xbox and PlayStation players join a modded server?

Only if every mod is server-side. Console players cannot install mods, so any mod that requires a client install excludes them.

Why did my mods stop working after an update?

UE4SS and many mods depend on the exact game version. After an update they need updating too. Keep backups of the working mod setup and update deliberately.