OneMapToRuleThemAll

A Valheim multiplayer mod that synchronizes map exploration and pins across all players, with optional automatic discovery map pinning and a client-side proximity radar.

A huge thanks to Mydayyy and his excellent mod, ServerSideMap, and to Kitz_Bitz and his mod UnderTheRadar. Their excellent work and permission to utilize their code for reference helped the development of this mod.

This mod was developed for my own use but I figured why not share it for those interested. It comes with no support or guarantees.

Summary

Shared Map

All players on a server share a single map state. Explored fog-of-war is merged in real time — when one player uncovers an area, every connected player sees it too. Player-placed map pins are likewise synchronized so the whole server sees the same markers. Works in single-player as well, persisting state to a .one_map_to_rule_them_all.explored file alongside the world save.

Auto-Discovery Pins (optional)

When a player walks within a configurable radius of a tracked world object (ore deposit, pickable, location), a permanent shared pin is automatically placed on the map for all players. Pins use short abbreviation labels (e.g. Cu, Rb) and append a nearby-object count (e.g. Cu 3) when multiple of the same type are clustered together. Discovery pins are server-authoritative — the server controls which object types are tracked, what abbreviations are used, and the detection radii. Each player can independently toggle the visibility of any keyword on their own map without removing the pin for others.

Radar (optional)

A purely client-side proximity system that shows transient pins for nearby objects while the player is within range; pins disappear automatically when the player moves away. Radar pins are never sent to the server or other players. Objects within a configurable cluster radius are merged into a single pin with a count label. The radar system is server-authoritative — the server controls which categories are active, detection radii, and which keywords are tracked. Each player can independently toggle per-keyword radar visibility.

Config Files

Client / Player Options

These settings are local to each player and stored in drummercraig.one_map_to_rule_them_all.cfg. Open ConfigManager in-game (default F1) to edit them live.

Client Section

Per-Keyword Visibility Toggles

Each tracked keyword has an individual on/off toggle in the ConfigManager. These control whether pins for that keyword appear on your minimap. Hiding a keyword does not remove the pin from the server or from other players' maps.

Visibility sections are organized by type:

Each section has a _ToggleAll entry at the top. Set it to false to hide every keyword in that section at once; set it to true to show them all. Individual keywords can still be toggled independently.

All visibility toggles default to true.

Server / Admin Options

These settings are server-authoritative and stored in One_Map_To_Rule_Them_All_Settings.cfg. When a client connects, the server pushes its configuration to them. Admin console commands require the caller to be a Steam-authenticated server admin.

General

Discovery System

Radar System

Per-Category Settings

Pickables — Per Biome

Pickables are configured in eight per-biome sections: Pickables.Meadows, Pickables.BlackForest, Pickables.Swamp, Pickables.Mountain, Pickables.Plains, Pickables.Ocean, Pickables.Mistlands, Pickables.AshLands.

Each biome section has:

Default keywords by biome:

Ores

Section: Ores

Default keywords: Copper, Tin, Iron, Silver, Obsidian, BlackMarble, Meteorite, Flametal

Locations

Section: Locations

Default keywords: Eikthyr, Hildir, Runestone, GDKing, TrollCave, Vendor, Bonemass, SunkenCrypt, Crypt, MudPile, BogWitch, DragonQueen, MountainCave, DrakeNest, FrostCave, GoblinKing, TarPit, Henge, GoblinCamp, WoodFarm, ShipWreck, SeekerQueen, InfestedMine, DvergrTown, Fader

Critters — Per Category

Critters are radar-only (no discovery pins). Each creature category defined in OneMapToRuleThemAll.creatures.txt gets its own config section: Critters.<CategoryName>.

Default categories and their radar radii (all 50 m): Bosses, Minibosses, Meadows, BlackForest, Swamp, Mountain, Plains, Mistlands, AshLands, Ocean, General.

Abbreviations

Each tracked keyword has a configurable short label used on discovery pin text. These live under Discovery.Abbreviations and can be changed without restarting the server. When an abbreviation is changed, newly discovered pins use the new label; existing pins keep their old label until om_renamepinabbreviations is run.

Admin Console Commands

All commands must be entered in the in-game console. The caller must be a server admin. On a dedicated server the RPC is forwarded automatically; in-game hosts execute directly.

Creatures File

OneMapToRuleThemAll.creatures.txt is created automatically in the BepInEx config folder on first run. It controls which creatures appear as radar pins, what display names and icons they use, and which category (and therefore radar radius) they belong to.

Format

category:displayname:internalname[:iconoverride]

• category — groups creatures under a shared radar radius setting (e.g. Bosses, Meadows).
• displayname — the label shown on the radar pin.
• internalname — used to match game objects. If it starts with Trophy, the Trophy prefix is stripped to derive the match keyword (TrophyGreydwarf → matches objects containing Greydwarf). Matching is case-insensitive and ignores underscores and spaces.
• iconoverride (optional) — name of a different ObjectDB item to use for the pin icon. Useful when a creature has no trophy of its own (e.g. Meadows:Greyling:Greyling:TrophyGreydwarf).

Lines starting with # are comments. Order matters — more-specific entries must appear before less-specific ones within and across categories, since matching uses substring checks.

Default Categories