A vanilla Valheim dedicated server accepts ten players at once, and the eleventh is turned away with "Server is full". There is no launch argument, config file or host setting that changes it, because the number is written into the game. Mods can raise it, and groups of fifteen or twenty do play that way, but the cost is real: more memory, more traffic, enemies that scale in odd ways, and a much higher chance that one player's connection makes everybody's evening worse. This post covers why the cap exists, what actually breaks past it, how the mods that lift it work, and what a larger group should budget for before installing one.
The general server setup - ports, launch arguments, saves - is in the Valheim dedicated server guide. This post assumes you already have a server running and a group that has outgrown it.
Where the 10-player cap comes from#
The limit lives in the server's networking code. When a client connects, it sends its peer information, and the server checks how many players are already in the world before accepting it. At ten, the connection is refused with a "full" status, which the client shows as Server is full. Nothing in the dedicated server's launch arguments touches this check, which is why a search for -maxplayers turns up nothing: the argument does not exist.
Iron Gate chose ten for reasons that are visible once you understand how the game shares out work:
- Zone ownership. The world is divided into zones, and each zone with players near it is simulated by one client - normally the first player who walked into it. The server stores the world and relays state, but a lot of the actual simulation happens on players' machines. Every extra player is another machine owning zones and another connection that every other nearby client has to hear from.
- Object synchronisation. Everything in the world - a chest, a log, a dropped piece of resin, a wall - is a networked object. When players gather, every client in the area has to stay in sync with every object the others are changing. That traffic grows faster than the player count when people cluster at one base.
- Balance. Creatures scale their health and damage with the number of players nearby, and boss fights, raid events and resource rates are tuned for a group of a handful, not a crowd.
The cap is a design decision rather than a hard technical wall. The server will run past it. What it will not do past it is behave the way the game was tested.
What the eleventh player sees#
The refusal happens during the handshake, before the world loads, so the eleventh player sees the connecting screen and then the "Server is full" error and is dropped back to the menu. Nothing is written to the world and nothing is lost. A few behaviours catch groups out:
- Admins do not get a reserved slot. Being in
adminlist.txtdoes not let you past the check in vanilla. If ten friends are online and the admin needs to get in to fix something, somebody has to leave. - Crossplay players count the same. Steam, Microsoft Store and Xbox players all draw from the same ten slots. The PlayFab relay that crossplay uses does not add capacity.
- A dead connection holds a slot briefly. A player whose game crashed can stay in the player list until the server notices the connection has timed out. If someone is told the server is full straight after a crash, wait a minute and try again before assuming somebody else joined.
Mods that raise the limit#
Raising the cap means patching the check on the server. Because the check happens server-side, the setting that matters is the one on the server; what players need installed depends on the mod you use to do it.
The common route is ValheimPlus (the maintained community fork). Its config file, BepInEx/config/valheim_plus.cfg, has a [Server] section with an enable switch and a player count:
[Server]; Turn the section on, or nothing below appliesenabled = true; Maximum players on the servermaxPlayers = 16ValheimPlus is a large mod that changes dozens of other values, and it checks its own version between server and client, so choosing it to raise the cap means every player installs it too. That is fine for a PC-only group already running mods. For a group that otherwise plays vanilla, it is a lot of mod to take on for one number, and it locks out Xbox and Game Pass players entirely, since they cannot install anything. Key names in ValheimPlus have moved between forks and releases, so read the generated file after the first start rather than copying the block above blindly.
There are also small single-purpose mods on Thunderstore that only raise the limit. Search for "max players" in the Valheim community there, read when each was last updated, and prefer one that says it is server-side only. A one-job mod is less to keep current than ValheimPlus, but a small mod with one author is also the kind most likely to stop being maintained after a game patch. Malicious plugins and mods is worth a read before you install anything unknown on a server other people connect to.
Whichever you use, install it through BepInEx as described in Valheim server mods with BepInEx, and confirm in the startup log that it loaded. A limit mod that silently failed to load looks exactly like vanilla: the eleventh player is refused and nobody knows why.
What breaks past ten players#
Nothing crashes at eleven. Things get gradually worse, and the order they get worse in is predictable.
Enemy scaling
Creatures gain health and damage for each additional player within range of them. In current builds the scaling counts players within roughly 200 metres and stops counting at five, so a fight with twelve people standing around a boss is not twelve-player difficulty - it is five-player difficulty with twelve people hitting it. Bosses melt, and raids that were built to pressure a small group become trivial. The opposite problem appears at the edges: a lone player wandering near a crowded base gets the scaled-up creatures without the crowd to fight them. The exact constants have changed between versions, so treat the numbers as a guide. If the group wants a challenge, the combat world modifier described in Valheim world modifiers and presets is the honest lever, rather than hoping more players makes it harder.
Network load at the main base
The real limit for big groups is not the server, it is the main base. When fifteen people stand in the same few zones, every client has to keep up with every object the others are touching: smelters filling, chests opening, carts moving, building pieces placed and destroyed. Valheim sends world updates at a limited rate per connection, and when the queue backs up the symptom is rubber-banding, doors that open late and items that pop back into chests. The player with the worst connection usually owns at least one of the busy zones, which makes it worse for everyone near them.
That is the effect described in Valheim server performance and lag, magnified. A larger group feels it first at the portal hub and the smelting area, because those are where everybody is at once.
Memory and save time
More players explore more of the map in parallel, and every explored and built-on zone adds to the world file and to what the server holds in memory. A group of twenty does not just use more RAM while they are online; they produce a bigger world faster, and the save pause grows with it. That pause happens every -saveinterval seconds, and with a large world and a large group online it is noticed.
What a bigger group costs the server#
These are working figures from groups that run past the cap, not guarantees. A world with heavy terraforming or hundreds of smelters will sit above them, and a world where everybody builds near spawn will lag before it runs out of memory.
| Players | RAM | CPU | What tends to fail first |
|---|---|---|---|
| Up to 10, vanilla | 3-4 GB | 1.5-2 cores | Nothing, if bases are spread out |
| 11-15, limit mod | 5-6 GB | 2-2.5 cores | Lag at the main base |
| 16-20, limit mod | 6-8 GB | 2.5-3 cores | Lag everywhere people gather, longer saves |
| 20+, limit mod | 8 GB and up | 3+ cores | Desync and kicks; the game was not built for it |
CPU clock speed matters more than core count, because the server's main loop leans on one thread; the extra cores in the table are for saving and networking running alongside it. Bandwidth is rarely the problem on the server side - Valheim sends little data per player - but upload speed on each player's home connection matters, because zone owners are sending updates to everybody near them. How much RAM does a Valheim server need has the detail for the vanilla range, and CPU vs RAM for game servers explains how to tell which limit you are actually hitting before you pay for more of the other.
On RE:NODE the Valheim line runs from 2 GB to 8 GB, so the top tier covers a modded group of around twenty with room for the mods themselves. Moving up a tier changes the limit on the existing server rather than rebuilding it, so you can start a tier lower and move when the memory graph on the console says so, rather than guessing up front.
Making a large group work#
Most of the lag a large group feels is caused by where people stand, not by how many there are. The fixes cost nothing:
- Spread the bases out. Separate bases mean separate zones with separate owners. Twenty people in four bases is far smoother than twenty in one. Base placement for shared servers goes into the spacing.
- Keep the portal hub small. A portal hub with forty portals and a wall of chests is the most expensive place on the map. Put storage near where it is used, not all next to the hub.
- Shorten the save interval, not lengthen it. It is tempting to stretch
-saveintervalto avoid the save pause. On a big world that only makes the pause less frequent and the loss on a crash bigger. Ten to twenty minutes is the sensible range. - Restart on a schedule. A weekly restart at an hour nobody plays keeps memory from creeping. Restart schedules that help covers how often and why.
- Ask the player with the worst connection to stay out of the busiest zone when they can. It is not fair, but it is the single biggest improvement in a crowded base, because zone ownership puts the simulation on their machine.
Mods that improve networking help as well. Better Networking by CW_Jesse, for example, compresses traffic and changes how much is sent per update. Mods in this category typically need installing on the server and every client, and like any mod they need updating after game patches. Read the mod's page for which side it belongs on before assuming.
Alternatives to raising the cap#
Before patching the server, consider whether the group actually needs everyone in one world at once.
- Two worlds, one plan each. A main world and a second for the people who want to rush ahead or play a harder preset. Characters live on the player's machine, so anyone can move between the two with their gear. Each server is a normal vanilla server with its own ten slots.
- A schedule. Many large groups find that only six or seven people are ever on at the same time. Watching who is actually online for a fortnight before buying anything is worth it; the cap may never be reached.
- Crossplay first, mods second. If even one person in the group plays on Xbox, a limit mod that needs a client install is out. A server-side-only limit mod is the only kind compatible with console players - and it is worth checking that a mod really is server-only before promising anyone a slot.
Troubleshooting a raised limit#
The eleventh player still gets "Server is full". The mod did not load or its setting is not enabled. Check the startup log for the plugin's loading line, then check the config for an enabled switch on the section. ValheimPlus in particular ignores every value in a section whose enabled is false.
Players are kicked on connect after installing the mod. The mod enforces a version check and the client does not have it, or has a different version. That is covered in detail in kicked for mod version mismatch.
It worked yesterday and stopped after an update. A game patch landed and the limit mod is either failing to load or loading against a method that no longer exists. Look for an exception mentioning the mod in BepInEx/LogOutput.log. Until the author updates it, the server is back to ten.
The server shows 12 players but everyone lags. Look at where they are standing. Large groups lag where they gather, and the fix is usually distance between bases rather than a bigger plan.
Memory reaches the limit during busy evenings. The world has grown. Check the memory graph against the player count over a week; if it is the world, a larger tier helps, and if it climbs steadily with no players online, a scheduled restart does more.
FAQ#
Can I raise the Valheim player limit without mods?
No. The check is in the game code and no launch argument, config file or host setting changes it. Any host that advertises more than ten Valheim players is running a mod.
Do players need the mod installed to join a server with a raised limit?
Only if the mod requires it. The player count check itself happens on the server, so a server-side-only limit mod needs nothing on clients. ValheimPlus, the common choice, checks its version between server and client, so with it everyone needs the same version installed.
Does the player limit include admins?
Yes. Vanilla Valheim has no reserved admin slot. If ten people are online, an admin is refused like anyone else.
Is 20 players on one Valheim server realistic?
It works for groups who spread out and play at different times. It is miserable for groups who all play at once at one base. The server copes with 8 GB and three cores; what struggles is the networking between players gathered in one place.
Does crossplay change the player limit?
No. Xbox, Game Pass and Steam players share the same ten slots, and console players cannot install mods, so a limit mod that needs a client install makes the server PC-only.
