PrismaMCM — Mod Configuration Menu

PrismaMCM is a companion plugin that gives any mod a settings screen without requiring C++ code. You drop a config.json file into your mod’s data folder and PrismaMCM renders the controls, reads current values, and writes changes back — directly to Papyrus auto-properties, TESGlobal forms, or INI files.

Requires: PrismaUI_F4 + PrismaMCM both installed.

How it works

When a game is loaded, PrismaMCM scans Data\MCM\Config\ for any subfolder containing a config.json. For each one it finds, it reads the current values from your Papyrus scripts or globals, and makes them available in the MCM interface.

Opening the MCM (default F12, or the button in the Pause menu):

1. PrismaMCM re-reads all your current values live
2. Displays them in the HTML interface
3. When the player changes a control, PrismaMCM writes the new value back immediately — directly to the Papyrus VM property or TESGlobal, no restart required

File layout

Data\
  MCM\
    Config\
      YourModName\
        config.json          ← you write this
    Settings\
      YourModName.ini        ← auto-created for INI-backed settings
  F4SE\
    Plugins\
      PrismaMCM.ini          ← optional: change the hotkey

The subfolder name under Config\ must match the modName field in your config.json.

Minimal config.json

{
  "modName": "MyMod",
  "displayName": "My Mod",
  "pages": [
    {
      "pageDisplayName": "Settings",
      "content": [
        {
          "type": "slider",
          "id": "DamageScale",
          "text": "Damage Multiplier",
          "valueOptions": {
            "sourceType": "PropertyValueFloat",
            "sourceForm": "MyMod.esp|800",
            "propertyName": "DamageMultiplier",
            "min": 0.5,
            "max": 3.0,
            "step": 0.1
          }
        }
      ]
    }
  ]
}

Top-level fields

Pages

"pages": [
  {
    "pageDisplayName": "General",
    "content": [ ... ]
  },
  {
    "pageDisplayName": "Audio",
    "content": [ ... ]
  }
]

Control types

section — visual divider with a heading

{ "type": "section", "text": "Combat Settings" }

spacer — blank space

{ "type": "spacer", "numLines": 1 }

text — read-only label

{ "type": "text", "text": "Changes take effect immediately." }

slider — numeric range picker

{
  "type": "slider",
  "id": "SprintSpeed",
  "text": "Sprint Speed",
  "help": "How fast the player sprints. Default is 1.0.",
  "valueOptions": {
    "sourceType": "PropertyValueFloat",
    "sourceForm": "MyMod.esp|800",
    "propertyName": "SprintSpeed",
    "min": 0.5,
    "max": 3.0,
    "step": 0.05
  }
}

switcher — on/off toggle

{
  "type": "switcher",
  "id": "HardcoreMode",
  "text": "Hardcore Mode",
  "help": "Enables permadeath and resource scarcity.",
  "valueOptions": {
    "sourceType": "PropertyValueBool",
    "sourceForm": "MyMod.esp|800",
    "propertyName": "HardcoreMode"
  }
}

dropdown — pick from a list

{
  "type": "dropdown",
  "id": "Difficulty",
  "text": "Difficulty",
  "valueOptions": {
    "sourceType": "PropertyValueInt",
    "sourceForm": "MyMod.esp|800",
    "propertyName": "Difficulty",
    "options": ["Easy", "Normal", "Hard", "Survival"]
  }
}

The stored value is the zero-based index of the selected option as a string ("0", "1", "2", "3").

button — trigger an action

{
  "type": "button",
  "text": "Reset to Defaults",
  "help": "Resets all settings for this mod.",
  "action": {
    "type": "CallFunction",
    "form": "MyMod.esp|800",
    "function": "ResetDefaults"
  }
}

valueOptions — source types

Every control that stores a value needs a valueOptions block. The sourceType field controls where the value is read from and written to.

PropertyValueFloat / PropertyValueInt / PropertyValueBool

Reads and writes a Papyrus auto-property attached to a script on a form.

"valueOptions": {
  "sourceType": "PropertyValueFloat",
  "sourceForm": "MyMod.esp|800",
  "propertyName": "MyPropertyName",
  "min": 0.0,
  "max": 10.0,
  "step": 0.5
}

sourceForm local ID explained:

If your quest form is 0x00000800 in xEdit (the 00 file prefix stripped, leaving 000800), write it as "MyMod.esp|800". Use the last 3 hex digits for normal ESPs — do not include the file index byte.

Requirement: The form at sourceForm must have a script attached to it in-game with the property already declared. A Quest form is the most reliable choice since it persists across cell changes.

No INI file is written for PropertyValue* types. The value lives entirely in the Papyrus VM.

GlobalValue

Reads and writes a TESGlobal form’s live float value.

"valueOptions": {
  "sourceType": "GlobalValue",
  "sourceForm": "MyMod.esp|801",
  "min": 1,
  "max": 5,
  "step": 1
}

The global’s value is updated immediately when the player moves the slider. No INI file is written. Papyrus scripts can read the global at any time via GlobalVariable.GetValue().

ModSettingFloat / ModSettingInt / ModSettingBool

Reads and writes Data\MCM\Settings\<modName>.ini. Use this for settings you want to persist as a file without needing a Papyrus script.

"valueOptions": {
  "sourceType": "ModSettingFloat",
  "min": 0.0,
  "max": 1.0,
  "step": 0.01
}

The INI key is taken from the control’s id field. The INI section defaults to Profile1 unless the id contains a colon: "id": "volume:Audio" writes to section Audio, key volume.

Papyrus integration

Reading a PropertyValue from Papyrus

After PrismaMCM writes a property, the new value is live in the Papyrus VM immediately. Any Papyrus code that accesses the property will see the updated value:

Scriptname MyMod_Quest extends Quest

float Property SprintSpeed = 1.0 Auto
bool  Property HardcoreMode = false Auto
int   Property Difficulty   = 1 Auto

; Papyrus reads the current values whenever it needs them —
; no event required, PrismaMCM has already updated them.
Function ApplySettings()
    Game.SetGameSettingFloat("fMoveSprintMult", SprintSpeed)
EndFunction

Reading a GlobalValue from Papyrus

GlobalVariable Property MyDifficultyGlobal Auto

; Read live value any time
float diff = MyDifficultyGlobal.GetValue()

Detecting when the MCM closes

PrismaMCM is not a Scaleform menu, so RegisterForMenuOpenCloseEvent("PrismaMCM") will not fire. The simplest pattern is to read your properties at the natural points in your script flow — on game load, on combat start, on cell change — rather than trying to react to the MCM closing.

For settings that must take effect the moment they change (e.g., adjusting a game setting float), use GlobalValue and poll the global in a recurring timer:

Event OnTimer(int aiTimerID)
    if aiTimerID == SETTINGS_TIMER
        Game.SetGameSettingFloat("fMoveSprintMult", SprintSpeedGlobal.GetValue())
        StartTimer(5.0, SETTINGS_TIMER)
    endif
EndEvent

Translation support

All text, help, displayName, and pageDisplayName fields support $KEY tokens that are replaced with strings from a Fallout 4 translation file.

Translation file locations (checked in order, first match wins):

Data\Interface\Translations\<modName>_<lang>.txt
Data\Interface\Translations\MCM_<modName>_<lang>.txt
Data\MCM\Config\<modName>\Translation\<anything>_<lang>.txt

Language is auto-detected from Fallout4.ini. Falls back to en if the language file is not found.

File format (UTF-16 LE with BOM, or plain UTF-8/ASCII):

$MY_TITLE	My Mod Settings
$SPRINT_TEXT	Sprint Speed
$SPRINT_HELP	How fast the player sprints.

Using tokens in config.json:

{
  "modName": "MyMod",
  "$displayName": "$MY_TITLE",
  "pages": [
    {
      "$pageDisplayName": "$PAGE_GENERAL",
      "content": [
        {
          "type": "slider",
          "id": "SprintSpeed",
          "$text": "$SPRINT_TEXT",
          "$help": "$SPRINT_HELP",
          "valueOptions": { ... }
        }
      ]
    }
  ]
}

Use $text / $help / $displayName / $pageDisplayName (with the $ prefix on the JSON key) to mark fields for translation lookup. Plain text / help fields are used as-is.

Hotkey

Default is F12. Change it in Data\F4SE\Plugins\PrismaMCM.ini:

[General]
iHotkeyCode=0x7B

The value is a BS_BUTTON_CODE (same as DIK_* scan codes). Common values:

The MCM button also appears on the vanilla Pause menu — no hotkey needed for keyboard-free navigation.

Categories

By default, all mods appear in an UNCATEGORIZED section. To group them:

Data\MCM\Config\PrismaMCM_categories.json:

{
  "categories": [
    {
      "name": "Combat",
      "mods": ["MyWeaponMod", "MyCombatAI"]
    },
    {
      "name": "Survival",
      "mods": ["MyNeedsSystem", "MyHardcoreMod"]
    }
  ]
}

mods entries must match the modName fields in each mod’s config.json. Mods not listed fall through to UNCATEGORIZED.

Full config.json example

{
  "modName": "FallenWorldAI",
  "displayName": "Fallen World — AI Settings",

  "pages": [
    {
      "pageDisplayName": "Combat",
      "content": [
        {
          "type": "section",
          "text": "Enemy Behaviour"
        },
        {
          "type": "slider",
          "id": "AggressionScale",
          "text": "Aggression Scale",
          "help": "Multiplies enemy aggression. 1.0 = vanilla.",
          "valueOptions": {
            "sourceType": "PropertyValueFloat",
            "sourceForm": "FallenWorldAI.esp|D63",
            "propertyName": "AggressionScale",
            "min": 0.1,
            "max": 5.0,
            "step": 0.1
          }
        },
        {
          "type": "switcher",
          "id": "FlankingEnabled",
          "text": "Flanking Behaviour",
          "help": "Enemies attempt to circle around the player.",
          "valueOptions": {
            "sourceType": "PropertyValueBool",
            "sourceForm": "FallenWorldAI.esp|D63",
            "propertyName": "FlankingEnabled"
          }
        },
        {
          "type": "dropdown",
          "id": "CombatStyle",
          "text": "Default Combat Style",
          "valueOptions": {
            "sourceType": "PropertyValueInt",
            "sourceForm": "FallenWorldAI.esp|D63",
            "propertyName": "CombatStyle",
            "options": ["Aggressive", "Defensive", "Balanced"]
          }
        }
      ]
    },
    {
      "pageDisplayName": "Performance",
      "content": [
        {
          "type": "section",
          "text": "Actor Limits"
        },
        {
          "type": "slider",
          "id": "MaxCombatActors",
          "text": "Max Combat Actors",
          "help": "Caps the number of actors in active combat at once.",
          "valueOptions": {
            "sourceType": "GlobalValue",
            "sourceForm": "FallenWorldAI.esp|D64",
            "min": 4,
            "max": 32,
            "step": 1
          }
        },
        {
          "type": "spacer"
        },
        {
          "type": "button",
          "text": "Reset All to Defaults",
          "action": {
            "type": "CallFunction",
            "form": "FallenWorldAI.esp|D63",
            "function": "ResetDefaults"
          }
        }
      ]
    }
  ]
}

Checklist before testing

• modName in config.json matches the folder name under Data\MCM\Config\
• sourceForm uses the local form ID (strip the file index byte)
• The form at sourceForm has a script attached with the correct property names
• Properties are declared Auto in the Papyrus script
• PrismaMCM.dll and PrismaUI_F4.dll are both installed
• F12 opens the MCM (or check Data\F4SE\Plugins\PrismaMCM.log for errors)