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.

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