Morrowind Mod:Mod File Format

Mod files (also called plugin files) for the TES3 Construction Set are essentially collections of records which are further divided into fields. Records generally correspond to objects in the construction set (e.g., a creature, a game setting, a dialogue entry), with the fine details of the object (e.g., health of a creature, a dialog entry text) being handled by the fields of the record.

A plugin file uses the following format:

• A single TES3 record (plugin information).
• A collection of records of varying types, as detailed below.

Note that the information on these pages is intended for mod files and may or may not apply to saved game files, which use a slightly different structure. In particular, saved game files include record types not documented here (e.g., CNTC, CREC, and NPCC, which record changes to containers, creatures, and NPCs). Also, saved games sometimes emit fields in a different order or include fields not present in plugins at all.

Record Types

Type Data Object ACTI Activator ALCH Potion APPA Alchemy Apparatus ARMO Armor BODY Body Parts BOOK Book BSGN Birthsign CELL Cell CLAS Class CLOT Clothing CONT Container CREA Creature DIAL Dialog Topic DOOR Door ENCH Enchantment

Type Data Object FACT Faction GLOB Global GMST Game Setting INFO Dialog response INGR Ingredient LAND Land LEVC Leveled Creature LEVI Leveled Item LIGH Light LOCK Lockpicking Items LTEX Land Texture MGEF Magic Effect MISC Misc. Item NPC_ Non-Player Character PGRD Path grid

Type Data Object PROB Probe Items RACE Race REGN Region REPA Repair Items SCPT Script SKIL Skill SNDG Sound Generator SOUN Sound SPEL Spell SSCR Start Script STAT Static TES3 Tes3 Header WEAP Weapon

Records

Internally, the readers in both the game and the Construction Set take the approach of looping through all fields and then taking action based on the field name found. This means that fields can appear in almost any order, and unrecognized fields will be ignored. The Construction Set writes files in a specific order, though, which is described on the individual record pages. If your application is writing a mod file, it is suggested that you follow this preferred format if possible.

In addition to the fields listed on each record's page, all records support a DELE tag, indicating that a mod is deleting a record from one of its master files. This is always a uint32. It usually has a 0 value, but SSCR and CELL records can have other values; these values are unused and appear to be vestigial.

Type/Size	Info
char[4]	Record type
uint32	Size of data field. (Must be at least 1)
uint32	Appears to be completely unused. May have been intended for additional flags.
uint32	Flags 0x0020 = Deleted (used internally, usually flagged in files by DELE field instead) 0x0400 = Persistent reference 0x0800 = Initially disabled (only used internally, but see CELL) 0x2000 = Blocked
uint8[dataSize]	Data (see Fields, below)

Fields

Type/Size	Info
char[4]	Field type
uint32	Size of data field (Size of 0 is treated as 1)
uint8[dataSize]	Data (format depends on record and field type)