Oblivion Mod:Save File Format/NPC

This page describes the save file format for both NPC_ and CREA change records, since the two records share an identical format. An NPC_ Change Record (change record type 35) describes changes to the game's non-player characters (NPC_ mod file records) -- and also to the player's character (in the NPC_ change record for formid 0x00000007). A CREA Change Record (change record type 36) describes changes to the game's creatures (CREA mod file records).

Values specified an NPC_ or CREA record affect all instances of that actor. Values specific to a single instance of the actor are provided in the appropriate ACHR or ACRE record. The majority of the player character information is detailed in the ACHR change record for formid 0x00000014, instead of in the NPC_ change record.

The following table summarizes the subrecords that have been found in NPC_ and CREA records:

Bit in Overall Flags	Hex Value of Bit	Subrecord Name	Size	Relative Location
0	0x00000001	Form Flags	4	1
2	0x00000004	Base Health	4	7
3	0x00000008	Base Attributes	8	2
4	0x00000010	Base Data	16	3
5	0x00000020	Spell List	variable	5
6	0x00000040	Factions	variable	4
7	0x00000080	Full Name	variable	9
8	0x00000100	AI Data	4	6
9	0x00000200	Skills	21	10
10	0x00000400	Combat Style	4	11
28	0x10000000	Base Modifiers	variable	8

The relative positions of the subrecords have all been confirmed; their contents (as far as they are understood) are based on actual save files.

Form Flags

The Form Flags subrecord is present when bit 0 (0x00000001) is set in any change record's overall Flags. Its length is a constant 4 bytes.

The Form Flags subrecord has been seen in nearly every type of change record, always associated with bit 0, always using the same name in the text dump files, and always using the same format. The only record types without any Form Flags (so far) have been: CELL, FACT, INFO, PACK, and QUST. Furthermore, in analyzed save files, bit 0 has never been set for any of those five record types, so it is possible that even for those records, bit 0 is reserved for the Form Flags subrecord.

Name	Type/Size	Info
flags	ulong	The record's current form flags. Related to form flags in mod files, but the meaning of some bits is unknown. Example: If an item from an ESM file was originally a quest item, and stopped being one, flags = 0x00000009 Example: If an item from an ESM file was not originally a quest item, and became one, flags = 0x00000409

Base Attributes

The Base Attributes subrecord is present when bit 3 (0x00000008) is set in a CREA/NPC_ change record's overall Flags. Its length is a constant 8 bytes. Each byte provides the base value (without fortifications or damage) of one basic attribute. The attributes are listed in order of their standard index. Unlike Morrowind save files, for the player character these are the attributes at the current level.

Name	Type/Size	Info
Strength	ubyte
Intelligence	ubyte
Willpower	ubyte
Agility	ubyte
Speed	ubyte	Note that speed has a slightly different meaning for creatures than for NPCs. In particular, some creatures have Speed=255.
Endurance	ubyte
Personality	ubyte
Luck	ubyte

Base Data

The Base Data subrecord is present when bit 4 (0x00000010) is set in a CREA/NPC_ change record's overall Flags. Its length is a constant 16 bytes, and its format follows that of the mod file NPC_ ACBS subrecord.

Name	Type/Size	Info
flags	ulong	Flag Meaning 0x00000001 Female 0x00000002 Essential 0x00000008 Respawn 0x00000010 Auto-calc stats 0x00000080 PC Level Offset 0x00000200 No Low Level Processing 0x00002000 No Rumors 0x00004000 Summonable 0x00008000 No Persuasion 0x00100000 Can Corpse Check 0x40000000 Unknown
baseMagicka	ushort	Base magicka For the player character, this is the magicka at 0 intelligence (i.e., the sum of the player's racial or birthsign Fortify Magicka bonuses). The player's actual base magicka is dynamically calculated from (baseMagicka + 2*Intelligence). Presumably this is to ensure that Fortify Intelligence and Damage Intelligence effects always alter the player's magicka. On the other hand, an NPC's magicka is unaffected by Intelligence changes.
baseFatigue	ushort	Base fatigue For the player character, this value is zero because fatigue is dynamically calculated from (Endurance + Strength + Agility + Willpower). As with magicka, this is presumably to ensure that Fortify/Damage Attribute effects alter fatigue, whereas an NPC's fatigue is impervious to such effects.
barterGold	ushort
level	short	Level (non-autocalc NPCs) or offset relative to player's level (autocalc NPCs)
calcMin	ushort	Minimum auto-calculated level.
calcMax	ushort	Maximum auto-calculated level.

Factions

The Factions subrecord is present when bit 6 (0x00000040) is set in a CREA/NPC_ change record's overall Flags. Its length is variable, but the parameters controlling its length are well-understood. The subrecord lists the NPC or creature's faction memberships, and rank within those factions.

Name	Type/Size	Info
factionsNum	ushort	Number of factions.
faction	struct[factionsNum]	Character's factions.
faction	iref	Faction's iref
factionRank	byte	The numerical value of the actor's rank within the faction. -1 is used when the actor has been suspended from the faction (either temporarily or permanently); 0 is the lowest-level (default) rank in the faction.

Spell List

The Spell List subrecord is present when bit 5 (0x00000020) is set in a CREA/NPC_ change record's overall Flags. Its length is variable, but the parameters controlling its length are well-understood. The subrecord lists the spells known by the NPC or creature.

Name	Type/Size	Info
spellCount	ushort
spellIds	iref[spellCount]	Array of spell irefs (SPEL records).

AI Data

The AI Data subrecord is present when bit 8 (0x00000100) is set in a CREA/NPC_ change record's overall Flags. Its length is a constant 4 bytes. The meaning of the data contained in the AI Data subrecord is unknown, however, the observed values are consistent with 4 separate ubyte variables, each of which is set to a multiple of 5 (e.g., 5,100,80,80).

Name	Type/Size	Info
unknown	ubyte[4]	Constant length of observed subrecords.

Base Health

The Base Health subrecord is present when bit 2 (0x00000004) is set in a CREA/NPC_ change record's overall Flags. Its length is a constant 4 bytes, and it provides the NPC or creature's base health.

Name	Type/Size	Info
baseHealth	ulong	For NPCs, both auto-calc and not, this is the character's base health (health when undamaged, without and fortification bonuses). For the player character, this is the health at 0 endurance, i.e. the sum of the (Endurance/10) bonuses gained each time the player levels. The player's actual base health is dynamically calculated from (baseHealth + endurance*2). As with magicka and fatigue, this is presumably done to ensure that Damage Endurance and Fortify Endurance always alter the player's health. An NPC's health is immune to such effects.

Base Modifiers

The Base Modifiers subrecord is present when bit 28 (0x10000000) is set in a CREA/NPC_ change record's overall Flags. Its length is variable, but the parameters controlling its length are well-understood. This subrecord is used to record changes to miscellaneous actor attributes.

Interpretation of the subrecord is based on a limited number of samples, but seems reasonable. For example, index 45 (Blindness) is set to 100 for the Blind Moth Priests and Dredhwen; index 69 (Vampirism) is set to 100 for known vampires (except Jakben and Janus Hassildor, for whom the value is 25 and 50, respectively). For the player, this section contains any racial modifiers (e.g., resist disease 75%). Indices in the ranges 0-8 and 12-32 have not been seen, presumably because the Base Attributes and Skills subrecords are used for such data.

Name	Type/Size	Info
modCount	ushort
modifiers	struct[modCount]
valueIndex	ubyte	See Actor Value Indices to decode the indices. The same index can appear multiple times in a single NPC_ subrecord (with the same value listed each time); presumably these values are redundant rather than cumulative.
modValue	float	Previous documentation incorrectly listed the value's type as ulong.

Full Name

The Full Name subrecord is present when bit 7 (0x00000080) is set in a CREA/NPC_ change record's overall Flags. It contains a variable-length string, providing the new name of the NPC or creature.

Note that CELL change records can also contain a "Full Name" subrecord with the same contents, but in CELL records, its presence is triggered by bit 4, not bit 7.

Name	Type/Size	Info
fullName	bstring	New full name for character.

Skills

The Skills subrecord is present when bit 9 (0x00000200) is set in a CREA/NPC_ record's overall Flags. Its length is a constant 21 bytes. Each byte provides the base value of one skill. The skills are listed in order of their standard index.

Name	Type/Size	Info
Armorer	ubyte
Athletics	ubyte
Blade	ubyte
Block	ubyte
Blunt	ubyte
Hand To Hand	ubyte
Heavy Armor	ubyte
Alchemy	ubyte
Alteration	ubyte
Conjuration	ubyte
Destruction	ubyte
Illusion	ubyte
Mysticism	ubyte
Restoration	ubyte
Acrobatics	ubyte
Light Armor	ubyte
Marksman	ubyte
Mercantile	ubyte
Security	ubyte
Sneak	ubyte
Speechcraft	ubyte

Combat Style

The Skills subrecord is present when bit 10 (0x00000400) is set in a CREA/NPC_ record's overall Flags. Its length is a constant 4 bytes, and it provides information on the actor's current combat style.

Name	Type/Size	Info
combatStyle	iref	iref pointing to a CSTY (Combat Style) record