Inferno

Server-side control over every fire, torch and fuel-burning station in Valheim. Players install nothing, so it works with Xbox / Game Pass crossplay.

Source code, documentation and issue tracker: https://github.com/krab7191/valheim_inferno_mod

Status: beta. Every feature is unit-tested. Features marked Available have also been verified in-game on dedicated servers (local and hosted) with vanilla PC clients; the others are awaiting in-game testing (see Compatibility).

Features

Items that are not light sources (smelters, blast furnaces, ovens, …) keep vanilla behaviour until you change them. Items without fuel (e.g. the charcoal kiln) and fires with infinite fuel are not listed.

Installation (server)

With a mod manager (r2modman, Thunderstore Mod Manager, or your host's Thunderstore mod installer): install GrundleLord-Inferno. BepInExPack Valheim is installed with it.

By hand:

1. Install BepInExPack Valheim on the server (most hosts have a one-click option).
2. Copy Inferno.dll and Inferno.Core.dll (in the download's plugins folder) to the server's BepInEx/plugins/Inferno/ folder.
3. Restart the server. The log (BepInEx/LogOutput.log) shows Inferno … loaded and lists every item it found.
4. Settings are in BepInEx/config/GrundleLord.Inferno.cfg (created on first start). A fully commented sample-config.cfg comes with the download (also on GitHub).

Players don't install anything. A one-page guide for players (also console players) explains how to use Inferno with signs.

Commands

Three ways to type the same commands:

The F5 form borrows the vanilla listkeys command because Valheim only forwards built-in server commands to the server. Without Inferno it just lists world keys, so it is harmless.

<item> is the name as shown in game, e.g. hot tub, standing wood torch, campfire (case, spaces and punctuation don't matter; a name shared by several items changes all of them); a word that selects every item with it in its name, e.g. torches, braziers, fires, lanterns; or a group: all, lights, stations. Internal names like piece_bathtub work too. Typos get "did you mean" suggestions. When a word selects several items, the reply lists them.

Presets set everything in one go: eternal = always on (the default), night = lit 18:00–06:00 and never uses fuel, vanilla = plain game behaviour. They apply to all lights unless you name something (!fires preset night torches); vanilla without a name applies to everything.

Replies appear top left for a few seconds and stay in the game's message log (Compendium → Logs). A command written on a sign is replaced by a short answer, so the result stays readable until you write the next command.

Example: torches that light at dusk and never need fuel. One command: !fires preset night torches. That's the same as doing it by hand (always on overrides the schedule, so it's switched off):

!fires alwayson torches off
!fires burnrate torches -10
!fires schedule torches night

Changed your mind? !fires undo.

Only your base: nearby. Add nearby after the item to change only the fires around you (chat, F5) or around the sign, e.g. !fires preset night nearby or !fires burnrate torches nearby -5.

• Inside a ward, "nearby" means that ward's area, and only players with access to the ward (its builder and the players they added) can change its fires: the same rule as building there.
• Without a ward it means everything within 20 m, and anyone may change it, as with building.
• With a number, e.g. nearby 2, it means exactly that many metres (1–100) around you or the sign, even inside a ward. Ward permission still applies to every fire. The number goes right after nearby, before the value: !fires burnrate torches nearby 5 -10.
• Those fires keep their own settings (saved with the fire, also after a restart); later changes to their item type don't affect them. !fires show nearby lists them; !fires reset nearby makes them follow their item type again.

Example: a clock. Place 24 torches a few metres apart, each with a sign right next to it. On each torch's sign write !fires burnrate nearby 2 -10, then that torch's hour, e.g. !fires schedule nearby 2 13:00 14:00 (the last one 23:00 00:00). Exactly one torch is lit at any time.

Always on vs. burn rate and schedule: while always on is on, burn rate and schedule have no effect. Setting a burn rate or a schedule window therefore switches always on off for those items (the reply tells you). Turning always on back on keeps your burn rate and schedule stored, so nothing is lost.

Configuration

Everything the commands change is stored in BepInEx/config/GrundleLord.Inferno.cfg, and edits to that file apply live. A fully commented sample-config.cfg comes with the download (also on GitHub).

Optional client mod (PC)

Players don't need anything. PC players may install the same Inferno files (plus ConfigurationManager, which many modded setups already have) to get:

• A settings menu: press F1, open Inferno. While connected to a server running Inferno, the menu shows the server's settings and changes apply to the whole server immediately (they are sent as normal commands, so the same permissions and logging apply). With AdminOnly on, non-admins see the settings read-only.
• Smoke toggle: items set to Smoke = off make no smoke for this player.
• No rain flicker: with IgnoreRain on, this player's game never puts lights out in the rain.

On a server without Inferno, or in single-player without a world loaded, the client mod does nothing. Version mismatches between client and server are detected; the menu is then disabled with a message.

Server ownership mode (experimental)

Normally the player nearest a fire "owns" it, and their game burns its fuel and switches it off in rain; Inferno corrects from the server. With ServerOwnership on, the server keeps ownership of every eligible fire instead:

• No player's game burns the fuel, so it changes only when Inferno says so: always-on fires never drop, burn rate and schedule are exact, and there are no update collisions.
• Rain and wind can't switch these fires off.
• Adding fuel and switching on/off are handled by the server, so nothing is lost.
• Deconstructing, repairing or damaging a fire briefly hands it to that player (30 s) so the game handles it normally. The action takes about a second longer than usual; if it doesn't happen, try again.
• Side effects: no sound or flash when adding fuel or switching these fires.
• Excluded (keep normal behaviour): fires that melt Deep North snow or spread fire, and pieces with other player-run parts (smelters, containers, …). The server log lists them.
• Turning it off gives every fire back immediately; Inferno also gives them back on shutdown.

Known limits

These come from how Valheim works and apply to any server-only mod:

• Rain, wind, roofs and water are checked on players' PCs. Some lights (e.g. candles, lanterns) switch themselves off in the rain; with IgnoreRain on, Inferno switches them back on within a few seconds, but they may flicker during storms. The server can't tell rain from a player's hand, so IgnoreRain also relights lights players switched off. Lights blocked by a roof or under water stay out.
• Burn rate is close, not exact, while a player is nearby. That player's game burns the fuel; Inferno corrects the amount every 5 seconds. While nobody is nearby, the server burns fuel itself, exactly, following the burn rate and the schedule.
• Chat commands need a second player online (see Commands); signs and the F5 console always work. Console players whose platform privacy settings block text chat can always use signs.
• Smoke can only be removed for players who have the client mod.
• Uninstall: stop the server normally (not a forced kill), then remove the files. Fuel levels stay as they are and burn normally afterwards.

Troubleshooting

1. Write !fires status on a sign (or listkeys fires status in the F5 console). If nothing answers, Inferno isn't running on the server. The last line shows errors since start.
2. Open the server's BepInEx/LogOutput.log (most hosts show it in their file manager). Search for Inferno:
   • the startup diagnostics block lists versions, crossplay on/off, other mods, and any other mod that hooks the same game methods as Inferno (the usual cause of conflicts);
   • every command, change and reply is logged;
   • errors are logged in full the first time and summarised if they repeat. Inferno skips the failing object and keeps running.
3. Report problems on GitHub Issues and include the startup diagnostics block and the first error.

Compatibility

Inferno targets the latest stable Valheim release only. New game patches are tested as they ship; older game versions are not supported.

License

MIT © 2026 GrundleLord.

Changelog

All notable changes are documented here. Format: Keep a Changelog; versioning: Semantic Versioning.

[Unreleased]

[0.3.2] - 2026-10-11

The preset fix is unit-tested only; not yet checked in-game.

Fixed

• !fires preset eternal nearby (or night) without an item name changed every fuel user around you, so nearby smelters and blast furnaces became always on with free coal. Presets with nearby now change only lights, as they do without nearby; name a station to include it (!fires preset eternal smelter nearby). Already affected stations: !fires reset stations nearby.

Changed

• IgnoreRain is no longer advertised: a server-only mod can't keep fires lit in the rain. Uncovered fires and torches smoulder with steam while it rains, as in vanilla; they keep burning and keep their fuel. Use a roof. The setting stays for the PC client mod and is no longer listed in help, status or the README feature list.
• README: clock example with 12 torches and a picture; nearby <metres> is now tested in-game (PC).

[0.3.1] - 2026-10-08

Released without in-game testing (unit-tested only), like 0.3.0.

Added

• nearby <metres> (1–100): a plain circle of that size around the sign or player, e.g. !fires schedule nearby 2 13:00 14:00 changes only the torch right next to the sign. Ward permission still applies. Without a number, nearby still means the ward's area, or 20 m.

[0.3.0] - 2026-10-08

Released without in-game testing (unit-tested only). Changes since 0.2.x run on every fire, not only for players who use nearby. If something misbehaves, go back to 0.2.2 and please report it on GitHub.

Added

• Per-base control with nearby: add nearby to an item command to change only the fires around you or the sign, e.g. !fires preset night nearby or !fires burnrate torches nearby -5. Inside a ward, "nearby" means that ward's area and only players with access to the ward can change its fires (same rule as building); without a ward it means everything within 20 m. Those fires keep their own settings (saved with the fire, also after a restart); !fires reset nearby makes them follow their item type again; !fires show nearby lists them.
• Wrong word order gets a suggestion: !fires all preset eternal → "Did you mean: !fires preset eternal all".
• !fires undo steps back through your last 10 changes (was 1).
• Performance line in the server log every 10 minutes (objects tracked, time per pass and sweep, writes, errors).
• !fires status also counts fires with their own settings and wards.
• Link to the GitHub repository on the mod page; README links to the tester guide and sample config work on Thunderstore.

[0.2.2] - 2026-10-07

Changed

• Help is easier to read on screen and in the message log: one command per line with a short description, and topic pages !fires help items, !fires help presets, !fires help admin (each fits on screen).

[0.2.1] - 2026-10-07

Changed

• Setting a burn rate or a schedule window on an always-on item now switches always on off, so the setting takes effect (the reply says so). Turning always on back on keeps the stored burn rate and schedule for later. schedule … off leaves always on alone.

Fixed

• Commands written with formatting, e.g. <color=green>!fires status on a sign, were ignored. Formatting tags are now ignored when reading commands, and the answer on the sign keeps the player's formatting.

[0.2.0] - 2026-10-07

Tested on a local dedicated server (Valheim 1.0.17): presets, word groups, instant sign answers. undo is unit-tested but not yet tested in-game.

Added

• Presets: !fires preset eternal|night|vanilla [item] (e.g. !fires preset night = lights lit 18:00–06:00 without using fuel).
• Word groups: torches, braziers, fires, lanterns, … select every item with that word in its name; replies list what changed. Schedule words night and day.
• !fires undo reverts your own last change.

Changed

• New fires are filled and sign commands answered within about a second (previously up to 30 s / 5 s).
• !fires torch style words now select matching items instead of only suggesting names.

[0.1.0] - 2026-10-07

First public beta. Tested in-game on a local dedicated server (Valheim 1.0.17) with vanilla PC clients.

Added

• Error reporting: each problem is logged once in full (repeats summarised), one failing object never stops Inferno, startup diagnostics (versions, crossplay, other mods, shared hooks), error count in !fires status.
• Thunderstore package (GrundleLord-Inferno); MIT license.
• Project scaffold: core library, BepInEx plugin, test project with a 100 % coverage gate.
• In-game clock conversion that matches Valheim's own day/night rescaling (06:00 = sunrise, 18:00 = sunset).
• Server-side plugin: discovers every fuel-burning item, keeps light sources (incl. hot tubs) always on by default, burn rate −10…+10, daily on/off schedule, IgnoreRain, shutdown restore of scheduled-off lights.
• Commands via chat (!fires …), signs (!fires …) and the F5 console (listkeys fires …); groups all, lights, stations; AdminOnly / HideCommands settings.
• Server burns fuel itself for fires nobody is near (follows schedule and burn rate; no burst on arrival).
• Reliable server writes for refills and schedule switches; fewer network writes for always-on items.
• Each game hook installs separately (a game update can't take the whole mod down); version-mismatch warning; startup list of lights that react to rain.
• Experimental server ownership mode (ServerOwnership, off by default): the server owns fires, so fuel only changes when Inferno says so; add-fuel and switch actions are handled on the server; other actions briefly hand the fire to the player.
• Optional PC client mod (same DLL): ConfigurationManager (F1) menu that shows and edits the server's settings live through a private channel vanilla clients never see; per-item smoke toggle; no rain flicker with IgnoreRain.
• !fires status for remote testing; per-player rate limit, command length cap, batched broadcasts and menu edits; plain-language tester guide for players without mods.
• Commands accept in-game item names (!fires alwayson hot tub on) with suggestions for typos; replies are one combined message, sign commands leave a short answer on the sign, and replies are logged on the server.
• BepInEx config file with live reload; audit log of every command, change and config-file edit.
• Release packaging (dotnet build -c Release → artifacts/Inferno-<version>.zip), sample config, in-game test checklist.