ESM file format

Overview of record types found in Fallout3.esm

For those who have previously worked with Oblivion, many of these will be familiar to you.

GMST -- Game settings. These are variables which control many internal functions within the game, such as run speed, jump height, how much skills affect damage, how easy it is to sneak, how condition affects weapons, and many other neat things.

TXST -- Texture Settings (?). These seem to be related to what sorts of textures are being applied to the variants of items, such as grimy, dirty, ect. This system was likely used to get around the "every recolor needs a seperate mesh" issue that Oblivion had. This system also seems to be used for many other things related to textures which may make use of the same benefits of variation; rocks, weapons, decals, ect.

MICN -- Menu Icon. Unknown, may not be used.

GLOB -- Global Variable. Like in Oblivion, these are variables which are used across scripts, or which control certain, important, things. Many of the ones listed in the .esm are quest related, so care should be taken when altering.

CLAS -- Class. Similar to Oblivion, these define some of the base settings for a "class" of NPCs. The specific use, or values related to this are not currently clear, but likely refer to tagged skills.

FACT -- Faction. Used for controlling ownership, dispositions, and certain behavior (through scripts or dialogue links).

HDPT -- Head Part (?). Entries related to things such as beards, eye-brows, eyepatches, ect are defined here.

HAIR -- Hair. Defines hair styles. Both the .nif and .dds are linked here. Color is controlled at actor.

EYES -- Eyes. Defines eye colors.

RACE -- Race. Defines race. More specifically, controls generic features; head, ear, teeth, tongue, meshes. May also control some more generic attributes, such as skin tone, face morphs, texturing. Old people and children are seperate races, as are Ghouls.

SOUN -- Sound. Controls settings related to specific sounds, as well as linking to the individual sound file. These are mostly things like ambient, creature, collision, or weapon sounds.

ASPC -- Unknown. May be related to aspects of a given space.

MGEF -- Magic Effect. Although there are no spells in Fallout 3, Magic Effects are still used to control certain special effects such as; Addiction effects, trap effects, certain perk effects, and similar. ! ! This setting does not control the specific effects of various spells, but rather how they are handled internally by the game. These values are likely related mostly to visuals, or flags related to that effect. ! !

SCPT -- Script. These are the building blocks of most internal behavior related to quests, activators. ! ! MUST BE COMPILED FOR ANY CHANGES TO APPLY '''! !'''

LTEX -- Land Texture (?). Does not link to texture files, may control grass and havok information. (Unverified)

ENCH -- Enchantment. Controls appilied effects related to worn equipment, essentially the "+5 to repair" and similar bonuses which are on equipment. Certain weapons also have "enchantments".

SPEL -- Spell. Makes use of the defined MGEFs, controls the magnitude and actual effect within the game. For those who have modded or used Oblivion, these are the Spells, Abilities, and Powers. These control how much of an effect things like bobbleheads, addictions, and many perks (those that increase skills) have. They also control the effects certain weapon hits have (fire, lazer, plasma).

ACTI -- Activator. All those things you can activate, or perform some function not listed elsewhere, linked to meshes (by location) and scripts (by formID).

TACT -- Talking Activator (?). Similar to normal activator, but may allow conversations (Unconfirmed).

TERM -- Terminal. All those computer terminals you deal with in game. Subrecords control functions directly (Unconfirmed).

ARMO -- Armor. Defines worn items such as clothing, armor, hats, glasses. Links to meshes, defines weight, value, links to enchantments, and Texture Settings, among other things. (unconfirmed)

BOOK -- Book. You read these. Controls world meshes/textures, inventory icons, and more.

CONT -- Container.

DOOR -- Door.

INGR -- Ingredients. Not used in Fallout, as noted by the only listing "DoNotCreateNewIngredientsWeArentUsingThemInFallout".

LIGH -- Lights. Make dark places brigher. Controls color, intensity, and various other light related things.

MISC -- Miscellaneous. The clutter of Fallout 3, everything from burned books to scrap metal to bobbleheads. Things you put in your invenory and carry around with you.

STAT -- Static. All those meshes related to structures or environment features which you stand on, run into, hide behind, but cannot move or affect in any significant way.

SCOL -- Unknown. Links to nif, contains data flags.

MSTAT -- Moving Static (?). Things you cannot directly interact with, but have animations like hanging bodies, birthday cake, cars, various effects.

PWAT --Placeable Water. Water which is related to an area (allows varied heights within a cell).

GRAS --Grass. Linked to grass meshes.

TREE --Tree. Linked to Tree meshes.

FURN --Furniture. Things with a specific action/positioning linked with them, eg; beds, chairs, various consoles, ect.

WEAP --Weapon. Links to weapon meshes, defines attributes related to the weapon.

AMMO --Ammo. Stuff that is used by projectile weapons.

NPC_ --NPCs. People mostly.

CREA --Creatures. Actors which are not NPCs.

LVLC --Leveled Creatures (?). (Unconfirmed)

LVLN --Leveled NPCs (?). (Unconfirmed)

KEYM --Keys. Used to unlock locked doors, containers, ect.

ALCH --Alchemy. The potions of Fallout 3. Food and drugs.

IDLM --Idle Animations (?). (unconfirmed)

NOTE --Notes. Things you pick up, and can read.

COBJ --Unknown. Unused. No entries.

PROJ --Projectile. Determines what a shot looks like when fired, also contains flags.

LVLI --Leveled Item. Controls liklihood (percent none), and what is created (by level), may also impact condition.

WTHR --Weather. Controls sky, lighting, and other ambient conditions related to weather.

CLMT --Climate. Controls frequency of weather, daylight time, and other environment related aspects.

REGN --Region. Controls regional attributes, many of the subrecords are used only durring region generation, and will not affect anything in game.

NAVI --Navigation (?). Only 1, very large entry, unknown.

CELL --Cell. Interiors are defined here. Very complicated.

WRLD --Worldspace. Worldspaces are defined here. Also very complicated.

DIAL --Dialogues. Stuff people say, and what happens when they say it.

QUST --Quests. Similar to Oblivion. Links scripts to an onmipersistant location, controling things in the world. Main difference is that some scripting related to the quests is being handled directly by the stages, rather than within the quest script (easier to organize, requires fewer conditionals, harder to alter without CS). ! ! Changes to scripts need to be compiled before they will work '''! !'''

IDLE --Idle Animations. These seem to be more of the generic animations, while IDLM seems to be mostly special animations (maybe linked to these (?)). Links to a KF.

PACK --Packages. Controls certain AI behavior, mostly movements, daily routines.

CSTY --Combat Style. Similar to Oblivion, controls combat behavior. (Unconfirmed)

LSCR --Load Screen. Controls what slides and text is shown when loading.

ANIO --Animation Object. Props used in animations (fork and knife, bottles, cups, cigaretts).

WATR --Water. Controls flags related to water by type, in Fallout 3, this would be color, cloudyness, radiation, and similar (unconfirmed).

EFSH --Effect Shader. Controls appearance of shaders.

EXPL --Explosion. Controls appearance, size, and force of explosions (unconfirmed).

DEBR --Debris. Defines debris created when blowing off limbs, ect (unconfirmed).

IMGS --Image Space. Unknown

IMAD --Unknown. Unknown. Related to certain visual effects.

FLST --Unknown. Fallout Lists? Seems to be related to repair or durability effects, but applies to other things.

PERK --Perk. Defines Perks. Much of what is related to a perk is controlled elsewhere, or is hard coded. (unconfirmed)

BPTD --Body Part Data. Unknown, may be VATS related.

ADDN --Addon (?). Seems related to temporary visuals caused by an item like; cigarette smoke, gun sparks, blood spatter.

AVIF --Actor Value Something Something (?). Seems to relate to Actor Values such as skills, S.P.E.C.I.A.L., and other things which impact actor ability. (unconfirmed)

RADS --Unknown. Radiation related (unconfirmed).

CAMS --Cameras. Used in VATS. (unconfirmed)

CPTH --Unknown. Seems related to CAMS, used in VATS. (unconfirmed)

VTYP --Voice Type. Used by dialogues/NPC (?) to create variations in voices.

IPCT --Impact. Determines effects on impact (unconfirmed).

IPDS --Impact Data Set. Controls other things related to impacts (unconfirmed).

ARMA --Arm Addon (?). Defines non-functional items (gloves, backpacks, hoses) to an actor.

ECZN --Unknown. Seems to be related to conditional respawns.

MESG --Message. Defines various message scrings.

RGDL --Ragdoll. Related to ragdoll attributes (unconfirmed).

DOBJ --Default Object Manager. Unknown.

LGTM --Lighting Template (?). Related to interiors, may only be used in the creation of new cells, rather than altering existing ones. (unconfirmed)

MISC --Music. Music Settings.

! ! This list was compilled going in order as the entries appear in TESsnip. Further organization and refinement may be needed. ! !

Many of the things listed above probably will not be made clear, or be made viable for modding until an official CS is released. However, attempts have been made to help facilitate people who would be willing to research further. Things listed here may not be 100% accurate, but are as accurate as can be determined by the author at this time. Regardless of completeness or correctness, this is better, and more useful than an empty page. Good Luck.