DayZ Enforce Script Skill

Always consult community.bistudio.com DayZ Modding and the Enforce Script Language Reference for authoritative API docs.

Overview

Enforce Script is a statically-typed, C-like scripting language embedded in the Bohemia Interactive Enfusion engine. It drives all gameplay logic in DayZ: items, players, AI, missions, GUI, economy, and RPC networking. Mods are distributed as .pbo archives compiled from .c script files layered on top of vanilla scripts.

When to Use This Skill

Trigger this skill when the user asks to:

Create or extend DayZ mod classes (items, players, weapons, missions, GUI menus)
Implement server-side logic (actions, spawning, persistence, economy)
Set up RPC communication between server and clients
Sync variables from server to client via NetSync
Create .layout XML files for in-game GUI panels and HUDs
Integrate with Community Framework (CF), DABS, or vanilla plugin systems
Debug Enforce Script compile errors or runtime issues

Quick Start

Minimal mod structure:

MyMod/
  config.cpp          <- PBO manifest + CfgPatches
  Scripts/
    4_World/
      MyMod_Item.c    <- your class

config.cpp

class CfgPatches
{
    class MyMod
    {
        units[]  = {};
        weapons[] = {};
        requiredVersion = 0.1;
        requiredAddons[] = { "DZ_Data" };
    };
};

Minimal modded class

// Scripts/4_World/MyMod_Item.c
modded class Apple
{
    override void OnConsume(PlayerBase player)
    {
        super.OnConsume(player);  // ALWAYS call super
        Print("[MyMod] Apple consumed by: " + player.GetIdentity().GetName());
    }
}

Critical Language Quirks

No ternary operator — use if/else instead of x ? a : b
auto != type inference — auto means autoptr (reference-counted ownership alias for ref)
No lambdas — use ScriptCaller for single callbacks, ScriptInvoker for multicast events
Primitives are never null — int, float, bool, string default to 0 / 0.0 / false / ""; only class instances can be null
modded class — the ONLY extension mechanism; produces one merged class. Always call super.* in overrides
super.* is mandatory — skipping it silently breaks every other mod in the chain
Write/read order in persistence — OnStoreSave and OnStoreLoad must write/read fields in identical order; mismatch destroys saves
No function overloading — methods must have unique names; use optional parameters instead
String format — string.Format("Value: %1", val) with 1-indexed %N placeholders (not %s/%d)

Mod Structure and Script Layers

Scripts load in layer order. Classes defined in lower layers are available to higher ones.

Folder	Layer	Purpose
`Scripts/1_Core/`	1	Engine primitives, proto definitions
`Scripts/2_GameLib/`	2	Base game library, input, menus
`Scripts/3_Game/`	3	Core gameplay (items, players, RPC enums)
`Scripts/4_World/`	4	World entities — most mod code lives here
`Scripts/5_Mission/`	5	Mission logic (server init, spawn tables)

A modded class PlayerBase must live in Scripts/4_World/; a modded class MissionServer in Scripts/5_Mission/.

Technical Terms

NetSync — engine-managed variable replication from server to all clients via RegisterNetSyncVariable* + SetSynchDirty()
RPC — Remote Procedure Call; integer-keyed messages sent between server and clients, received in OnRPC() overrides
CF / Community Framework — most-used modding library; adds module system, event bus, ModStorage persistence, and attribute-based actions
DABS — attribute-based action framework built on CF; declarative action definitions
PluginBase — vanilla service-locator pattern for decoupled gameplay subsystems
ScriptInvoker — multicast delegate (add/remove listeners, fire all)

Resources

Use the references for API lookups. Check patterns when implementing a common mechanic. Examples show complete working files.

references/player_api.md and references/game_api.md are the most frequently needed starting points.

references/

Core API documentation split by topic:

types_collections.md - Primitive types, string methods, array/map/set API, vector math, Math class
player_api.md - PlayerBase stats, vitals, agents, modifiers, inventory, NetSync, RPC helpers
item_api.md - ItemBase quantity/health/flags, action registration, spawning, config.cpp properties
game_api.md - GetGame(), GetWorld(), GetMission(), CreateObject, CallLater, logging
erpc_defines.md - Vanilla eRPCs/eAgents/eModifiers tables, custom ID range convention
file_paths.md - $profile/$saves path tokens, FileExist, MakeDirectory, JsonFileLoader, FileMode
gui_layout.md - Layout file format (WidgetClassNameClass syntax, RGBA colors, coords, all widget types, colums property, ItemPreviewWidget/PlayerPreviewWidget API)

integrations/

Guides for integrating with external frameworks and vanilla systems:

community_framework.md - CF module system, ModStorage persistence, event bus, inter-mod events
dabs_framework.md - Attribute-based action system, CF_ModAttribute, MVC layout, settings API
vanilla_plugins.md - PluginBase lifecycle, GetPlugin(), service-locator mod isolation pattern
central_economy.md - CE XML format, runtime CE with SpawnObject/DeleteObject, cfgeconomycore.xml
input_bindings.md - inputs.xml, UAInput API, GetUApi(), context guards, client-only input rules

patterns/ (optional)

Common implementation patterns for recurring mechanics:

netsync.md - RegisterNetSyncVariable*, SetSynchDirty, OnVariablesSynchronized, bitfield packing
persistence.md - OnStoreSave/OnStoreLoad, version header, write-order rules, CF_ModStorage alternative
rpc.md - ScriptRPC, RPCSingleParam, OnRPC switch template, client-to-server validation rules
modded_class.md - super.* rules, field injection, mod load order, compatibility patterns
singleton.md - Static s_Instance, lazy init, GetInstance(), JSON config with nested sub-objects
language_workarounds.md - No ternary, no auto type inference, no lambdas, no exceptions, no overloading

examples/ (optional)

Complete working script files demonstrating full implementations:

01_custom_item.c - Custom item with NetSync bool flag and versioned OnStoreSave/OnStoreLoad
02_custom_action_singleuse.c - Single-use ActionBase with CanPerformAction guard and server execution
03_continuous_action.c - Hold-to-complete action with progress bar, interrupt handling, cooldown
04_rpc_patterns.c - All three RPC APIs: RPCSingleParam, GetGame().RPC, ScriptRPC multi-field
05_mission_server.c - MissionServer overrides: PlayerConnect, PlayerDisconnect, OnUpdate tick
06_json_config.c - JsonFileLoader singleton config with nested sub-config and admin UID list
07_agent_modifier.c - Full SymptomBase + ModifierBase disease stack with agent threshold trigger
08_gui_menu.c - UIScriptedMenu with TextListboxWidget rows, EditBox filter, button handlers
09_scheduler_timer.c - CallLater, Timer, OnScheduledTick patterns with frame-skip guard
10_modded_playerbase.c - Comprehensive PlayerBase mod combining NetSync, RPC, persistence, actions
11_hud_plain_text.layout - HUD overlay with TextWidgets (float RGBA colors, pixel coords); companion modded Hud Update() script
12_menu_interactions.layout - Dialog with EditBoxWidgetClass filter, 2-column TextListboxWidgetClass, ButtonWidgetClass
13_item_preview.layout - Item inspect panel with ItemPreviewWidgetClass for live 3D model; rotate via SetModelOrientation

dayz-enfusion-script