Diablo II Save Game File Format

for Diablo II Expansion Set v1.13d

Updated July 1, 2012

This page was originally written by Trevin Beattie, whose site is no more (his latest version of this page is available here though).
Now this page is maintained by me, Yuri Sakhno (George1).

Introduction

This page describes the format of saved game files for the game Diablo II Expansion Set v1.13d. While the information presented here is mostly aplicable to earlier versions of the game, there were some drastic changes in version 1.10 (particularly, in how character stats are saved), so if you intend to read files of the versions of the game erlier than that, you would probably be better off opening that save in some recent version of the game and then saving it again (upgrading the saved game file).

(Note: all values larger than a byte are stored in x86 little-endian order — i.e., least significant byte first. A "short" is 2 bytes long, and a "long" is 4 bytes long. Values starting with "0x" are given in hexadecimal notation; otherwise they are decimal.)

File Header

Each save file starts with a file header. Depending on the circumstances, this may be the only section present in saved game file.

Byte Position Size Contents
0 long File identifier. This must be the value 0xAA55AA55.
4 long File version. The following values are known:
    0x47  v1.00 through v1.06
    0x57  v1.07 or Expansion Set v1.08
    0x59  standard game v1.08
    0x5C  v1.09 (both the standard game and the Expansion Set.)
    0x60  v1.10 and above
As it was outlined above, this document only covers version 0x60 of the file format.
8 long Size of the file, in bytes.
12 long Checksum of the netire save file. If you attempt to hack the file without storing the correct checksum afterwards, your game will fail to load. Fortunately, the checksum algorithm is very simple. After clearing the checksum field, you add up the values of all the bytes in the file, rotating the running total one bit to the left before adding each byte. Then store the result in this field.
16 long Active arms. Determines which weapon set is currently active.
20 16 chars Character name. The name may be up to 15 characters long; the rest of the field must be padded with null-characters. Remember the rules for Diablo II character names: 2-15 characters, containing only upper and lower case letters (A-Z), with the possible addition of one dash ( - ) or underscore ( _ ) as long as it is not the first or last character of the name.
36 byte
Character status. This is a bit field:
7 6 5 4 3 2 1 0
unknown Expansion
Character		 unknown Died Hardcore unknown
Note: the "died" bit indicates that your character has died at some point in the past. It is never cleared when you resume the game. To find out whether your character is currently dead, you need to look in the item list below to see if there is some corpse data. Obviously, if you have a hardcore character and this bit is set, you won't be able to play the game with that charcter anymore.
37 byte Character progression. This number tells (sort of) how many acts you have completed from all difficulty levels. It appears to be incremented when you kill the final demon in an act — i.e., Andarial, Duriel, Mephisto, and Diablo / Baal. There's a catch to that last one: in an Expansion game, the value is not incremented after killing Diablo, but is incremented by 2 after killing Baal. (The reason is unknown.) So it skips the values 4, 9, and 14.

I believe this value is used in determining your character's title. The title is one of the following values (depending on the character class' gender):

Value Standard Hardcore Value Expansion Hardcode Expansion
0-3 (no title) 0-3 (no title)
4-7 Sir / Dame Count / Countess 5-8 Slayer Destroyer
8-11 Lord / Lady Duke / Duchess 10-13 Champion Conqueror
12 Baron / Baroness King / Queen 15 Patriarch / Matriarch Guardian
38 2 bytes unknown; probably some kind of padding
40 byte Character class. The defined classes are:
     0x00  Amazon
     0x01  Sorceress
     0x02  Necromancer
     0x03  Paladin
     0x04  Barbarian
     0x05  Druid (Expansion character only)
     0x06  Assassin (Expansion character only)
41 2 bytes unknown; I've only seen the values { 16, 30 } here.
43 byte Character's level. This is the level shown on the character selection screen, but it should equal the level given in the character statistics section.
44 long unknown
48 long Time stamp. This is in the standard time() format of the number of seconds which have elapsed since midnight, January 1, 1970 (UTC).
52 long unknown
56 16 longs These are the skill Ids assigned to the hotkeys for Skill 1 through Skill 16. If a skill hotkey is not assigned to a skill, the value is 0xFFFF.

Hotkey definitions are stored in the character.key file. The structure of that file is not covered by this document.
120 long The action assigned to the left mouse button. The value of this field is a skill Id.
124 long The action assigned to the right mouse button. The value of this field is also a skill Id.
128 long In an Expansion character, the action assigned to the alternate left mouse button. (The button assignments are swapped when you swap weapons.)
132 long In an Expansion character, the action assigned to the alternate right mouse button.
136 32 bytes unknown
168 3 bytes These bytes indicate which difficulty the character is playing. The first byte corresponds to Normal, the second Nightmare, and the third Hell. If the value is zero, the character is not playing at that level. Otherwise, the value looks like this:
7 6 5 4 3 2 1 0
Active unknown Which Act the
character is in (0-4)
171 long Map Id. This value looks like a random number, but it corresponds with one of the longs found in the character.map file, according to the difficulty being played.
175 short unknown
177 short If your Expansion character has a mercenary who is currently dead, this field is non-zero.
179 long This looks like a random Id for your mercenary. It is 0 if you have never had a mercenary. If your mercenary has died or (in the standard game) been left behind when you move on to the next act, this field is still set to the last mercenary you had.
183 short This is a numerical index into the game's language-dependent string table for mercenary names. There is a separate list for each type of mercenary (Rogue Scout, Desert Mercenary, Eastern Sorceror, and Barbarian). Trevin wrote a list of mercenary names for the English 1.09 patch.
185 short This code determines the difficulty level and act where your mercenary was found, as well as the attribute of your mercenary (i.e. Cold, Fire, Lightning). Trevin wrote a list of the mercenary codes appended to the end of the mercenary name.
187 long Your mercenary's experience points.
191 144 bytes unknown

For the newly-created character, this is the only information present in the file (i.e. the file consists of just the header). The save file is extended (all other sections added) when you exit the game (even if you haven't done anything in it), but the very first save created by the game (i.e. right after you click the OK button on the character-creation screen) will be the save with just the header present. Such a save is still a legitimate save, which the game can successfully load.

Quest Completion Data

The quest data begins with the following header:

Byte Position Size Contents
335 4 chars The string identifier "Woo!".
339 6 bytes unknown; there are values { 0x06, 0x00, 0x00, 0x00, 0x2A, 0x01 } always present here.

The header is followed by three structures, one for each difficulty level. Note that the byte offsets given here are offsets into the structure; the first structure is at offset 345 in the file, the second one is at offset 441, and the third one at 537. You have to add the offsets from the table to these values to get the actual offset in the file for the corresponding field for the specific difficulty level.

Although there is some variation in the meaning of the bits per quest, some of the bits appear to have constant meaning.

Bit 0 indicates the quest is complete. If bit 0 is not set but the rest of the field is non-zero, then the quest has been started, but not finished.

Bit 1 generally means you have completed the requirements for the quest (i.e., killed the boss demon), and all that's left is to collect the reward — for example, "Charsi will imbue an item with magical power." Not all quests have this option. If this bit is set, bit 0 must be cleared.

Bit 2 is often set when an NPC gives you a quest.

Bit 12 is set when you have seen the swirling fire animation that closes a quest icon.

Bit 13 indicates the quest was completed in the current game; when you save the game and then reload it, all bit 13's are cleared.

Byte Position Size Contents
0 short This field contains a 1 if you have been introduced (by Warriv) to Act I.
2 6 shorts
These fields contain quest completion data for each quest in Act I.
short # Quest Notes
0 Den of Evil Bit 4 is set when you enter the Den.
1 Sisters' Burial Grounds Bit 4 is set when you enter the Burial Grounds.
2 Tools of the Trade Bit 6 is set when you pick up the Horadric Malus.
3 The Search for Cain Bit 4 is set when you enter Tristram.
Bit 10 indicates whether you have completed the secret Cow Level ("Moo"). If you want to fight the Cow King again, just clear this bit!
If you enter Act II without rescuing Deckard Cain, bit 14 will get set. You will not be able to rescue Cain yourself; the Rogues will have done it instead, and as a consequence, you will be charged a fee if you want Cain to identify items for you.
4 The Forgotten Tower Bit 2 is set when you read the Moldy Tome.
Bit 6 is set when you enter the Forgotten Tower.
5 Sisters to the Slaughter
14 short uncertain; perhaps this gets set to a non-zero value after you travel from Act I to Act II.
16 short This field contains a 1 if you have been introduced (by Jerhyn) to Act II.
18 6 shorts
These fields contain quest completion data for each quest in Act II.
short # Quest Notes
0 Radament's Lair Bit 4 is set when you find Radament.
1 The Horadric Staff Bit 4 is set when Cain tells you about the Viper Amulet.
Bit 5 is set when Cain tells you about the Staff of Kings.
Bit 10 is set when Cain tells you about the Horadric Staff.
Bit 11 is set when you make the Horadric Staff.
2 Tainted Sun Bit 2 is set when the sun goes out.
Bit 3 is set when Drognan tells you why.
3 Arcane Sanctuary
4 The Summoner
5 The Seven Tombs Bit 3 is set when you talk to Tyrael.
Bit 4 is set when you talk to Jerhyn (after killing Duriel).
Bit 5 is set when you kill Duriel.
Bit 6 is set when Atma congratulates you.
Bit 7 is set when Warriv congratulates you.
Bit 8 is set by Drognan.
Bit 9 is set by Lysander.
Bit 10 is set by Cain.
Bit 11 is set by Fara.
30 short uncertain; perhaps this gets set to a non-zero value after you travel from Act II to Act III.
32 short This field contains a 1 if you have been introduced (by Hratli) to Act III.
34 6 shorts
These fields contain quest completion data for each quest in Act III.
short # Quest Notes
0 Lam Esen's Tome
1 Khalim's Will
2 Blade of the Old Religion Bit 2 is set when you pick up the Gidbinn.
Bit 3 is set when Hratli asks you to find the Gidbinn.
3 The Golden Bird Bit 2 is set when Cain tells you about the Jade Figurine.
Bit 4 is set when Cain tells you about the Golden Bird.
Bit 5 is set when you are given the Potion of Life, and cleared again when you drink the Potion. (This prevents you from drinking more than one in a game.)
Bit 6 is set when you find the Jade Figurine.
4 The Blackened Temple
5 The Guardian
46 short uncertain; perhaps this gets set to a non-zero value after you travel from Act III to Act IV.
48 short This field contains a 1 if you have been introduced to Act IV.
50 6 shorts
These fields contain quest completion data for each quest in Act IV. Note that there are only three quests here, as opposed to 6 for the first three Acts.
short # Quest Notes
0 The Fallen Angel
1 Terror's End
2 Hell's Forge
3-5 unused It looks like quest data for Act IV still has place for 6 quests, despite the fact that this act only has 3.
62 short uncertain; perhaps this gets set to a non-zero value after you travel from Act IV to Act V in an Expansion game, but this assumption has not been verified yet.
64 short unknown; in an Expansion character, this was set to 1 after completing Terror's End and talking to Cain in act IV.
66 2 shorts unknown
70 6 shorts
These fields contain quest completion data for each quest in Act V.
short # Quest Notes
0 Siege on Harrogath Bit 3 is set when you find Shenk.
Bit 5 is set when Larzuk offers to socket an item for you.
1 Rescue on Mount Arreat
2 Prison of Ice Bit 7 is set when you read the Scroll of Resistance.
Bit 8 is set after you rescue Anya and talk to Malah.
3 Betrayal of Harrogath Bit 4 is set when Anya offers to personalize an item for you.
4 Rite of Passage
5 Eve of Destruction Bit 4 is set when Larzuk congratulates you.
Bit 5 is set when Cain congratulates you.
Bit 6 is set when Malah congratulates you.
Bit 7 is set by Tyrael.
Bit 8 is set by Qual-Kehk.
Bit 9 is set by Anya.
82 7 shorts unknown

Waypoints Data

The waypoints data begins with the following header:

Byte Position Size Contents
633 2 chars The string identifier "WS".
635 6 bytes unknown; there are values { 0x01, 0x00, 0x00, 0x00, 0x50, 0x00 } always present here.

The header is followed by three structures, one per each difficulty level. Note that the byte offsets given here are offsets into the structure; the first structure is at offset 641 in the file, the second one is at offset 665, and the third at 689. You have to add the offsets from the table to these values to get the actual offset in the file for the corresponding field for the specific difficulty level.

Byte Position Size Contents
0 2 bytes unknown; there are values { 0x02, 0x01 } always present here.
2 5 bytes Waypoints. This is a bitfield, with one bit assigned to each waypoint in LSB order — so bit 0 in the Rogue Encampment waypoint for Act I. The first waypoint in every Act is activated as soon as you enter that Act. There are 9 waypoints (bits) in each of Acts I, II, and III, and 3 waypoints (bits) in Act IV, so the last waypoint before Diablo (River of Flame) is bit 29 (since we start counting from 0). The first waypoint for Act V follows at bit 30, and continues to the last (ninth) waypoint in Act V at bit 38.

The first waypoint in each of the difficulty levels is always activated, even if you have never been to that difficulty level.
7 17 bytes unknown

There is an additional byte value at file offset 713 after the three waypoints structures. This byte always has value 0x01 and probably serves as some kind of trailer.

NPC Introductions

Trevin's data on the next section was very sketchy, and hasn't improved since at all.

Byte Position Size Contents
714 2 chars The string identifier "w4".
716 1 byte unknown
717 1 byte
You have been introduced to:
7 6 5 4 3 2 1 0
Warriv Charsi Kashya Akara Gheed
718 1 byte
7 6 5 4 3 2 1 0
Greiz Meshif Geglash Lysander Fara Drognan
719 1 byte
7 6 5 4 3 2 1 0
Alkor Asheara Cain Elzix
720 1 byte
7 6 5 4 3 2 1 0
Malah Anya Natalya Meshif Ormus
721 1 byte
7 6 5 4 3 2 1 0
Cain Qual-Kehk Nihlathak
722 3 bytes unknown
725 8 bytes Introductions repeated for Nightmare difficulty.
733 8 bytes Introductions repeated for Hell difficulty.
741 1 byte

It would appear that bits 1-6 of byte 741 get set after you take the caravan to Act II in Normal difficulty. Bit 7 of byte 741 through bit 1 of byte 743 get set after you sail to Act III. On entering Act IV, bits 2, 5, 6, & 7 of byte 743 and bits 0, 3, & 4 of byte 744 get set.

When you return to a previous act and talk to the NPC's, these bits are cleared.

You have yet to be welcomed back by:
7 6 5 4 3 2 1 0
Warriv ? Charsi Warriv Kashya Akara Gheed
742 1 byte
7 6 5 4 3 2 1 0
Greiz Jerhyn Meshif Geglash ? Fara Drognan ?
743 1 byte
7 6 5 4 3 2 1 0
Alkor Hratli Asheara ? ? Elzix
744 1 byte
7 6 5 4 3 2 1 0
? ? Ormus
745 4 bytes unknown
749 8 bytes Greetings repeated for Nightmare difficulty.
757 8 bytes Greetings repeated for Hell difficulty.

Character Statistics

The character statistics begin with 2-character identifier:

Byte Position Size Contents
765 2 chars The string identifier "gf".

From this point on, the contents of the file are variable, because character stats are stored in packed format and certain stats may be absent (if the stat is absent in the save file, its value is 0.

Starting from patch version 1.10 Diablo II stores stats differently than it used to be in previous game version. Every character stat is stored as a two-value pair. These pairs (and even the values inside them are not byte-aligned. They may start in the middle of one byte, and continue to the second. Here is the basic structure of the pair (note that field sizes are given in bits):

Field Size Description
9 Stat Id. This field determines the stat whose value is stored in the value-pair and, more importantly, the size of the next field in the pair.
variable The value that is to be assigned to the corresponding stat. The size of the field, in bits, is determined by the stat itself. Read on to find out where this information can be obtained.

The stats list is terminated by the 9-bit value of 0x1FF (all 9 bits are set), i.e. the entire list is read in a loop, where you read the Id first and, if that Id is 0x1FF, you exit the loop, otherwise you read the next n bits as a stat value and repeat the loop.

The Ids of stats (and sizes of values) are determined by the data-tables normally stored inside the game archive (the MPQ files). The file for this specific purpose is named ItemStatCost.txt, which is a kind of CSV file, but with tabulation characters used as separators instead of commas. The game actually uses the ItemStatCost.bin one, which is sort of a compiled version of the corresponding text file.

Here is an Excel-formatted ItemStatCost.xlsx file that contains the data for 1.13d patch with some nice formatting and extra comments. This file actually contains data from two tables, the one needed for the purpose of reading character stats is given on the ItemStatCost sheet.

The column ID specifies the Id of the stat, as stored in the 9-bit field of the two-value pair. The row containing that Id describes the stat. There is a textual name of the stat in the Stat column, as well as the size of the value, in bits, that follows the Id in the two-value pair. This size is specified by the CSvBits column. Only values that have value 1 in the Saved column (first 16 stats) are actually saved in the character stats section of the save file.

The stats described by the ItemStatCost table are as follows (in table below Stat Name corresponds to the value in the Stat column from the data table):

Stat Name Details
strength These stats are self-explanatory. They are always present.
energy
dexterity
vitality
statpts The number of Stat Points earned but not distributed. This stat may be absent from the save file if you have distibuted all stat points.
newskills The number of Skill Choices earned but not distributed. This stat may be absent from the save file if you have distibuted all skill points.
hitpoints Current amount of Life points.

These 6 stats are (usually) always present. (There is an exception: if your character is dead, the current Life stat will be gone!) They are also not plain integer values! Instead, each field is a fixed-point binary number, with a 24-bit integer part and an 8-bit fraction part. For example, if the Current Life stat contains the value 0x020AC0, then to get the amount of life remaining you take that value and divide by 256.0 to get 522.75 (rounding the number to an integer for display. Note that the current amount of Life, Mana or Stamina may be more than the base amount, because the base does not take into account any blessings bestowed by magical items you are carrying.
maxhp Base amount of Life points.
mana Current amount of Mana points.
maxmana Base amount of Mana points.
stamina Current amount of Stamina points.
maxstamina Base amount of Stamina points.
level Your character's level. This value must be in the range 1-99 (and is therefore always present, even on a new character, with a minor exception) and should be the same as byte 43 in the file header.
experience The amount of experience your character has. If you haven't killed a single monster in the game, your experience will be 0, and this field is not stored. Otherwise, this field is always present.
gold The amount of gold you are carrying with you (in your inventory or backpack). Just as a helpful reminder, the maximum amount of gold you may carry is directly proportional to your level, at 10,000 gold per level. Thus, a new character can only carry 10,000 gold pieces, but a level 99 character (the maximum) can carry nearly a million in gold (990,000).
goldbank The amount of gold you have stowed away (in stash). Just as a helpful reminder, starting from the 1.13c patch onwards, the maximum amount of gold in your stash does not depend on your character's level, and is now a flat cap of 2,500,000 instead.

As it was specified above, the stats list is terminated with a stat Id with a special meaning (the Id has value 0x1FF in this case), and the stat value for this stat Id is not stored (you may view it as a stat whose stat value is 0 bits in size). After that the remaining bits are padded with 0-bits to the nearest byte-boundary so that the next section is byte-aligned.

Character Skills

The character skills section begins with the 2-character header, "if". This is followed by 30 bytes, each byte corresponding to one of the character's special skills. To save space, Trevin listed the skills in a separate table.

Item List

The next major section of the save file is the item list. It begins with the following header:

Size Contents
2 chars The string identifier "JM".
short The number of items your character has. This includes items equipped, tucked in your belt, stored in your inventory, stored in your stash, and hidden in the Horadric Cube. It does not, however, include gems, runes, or jewels which have been inserted into a socketed item. (Those are counted as part of the item.)

This header is followed by a list of items. The format of the items is described on the Item Format page.

After the list of items, you will find another item list header similar to the one shown above; only this time the item count will be either 0 or 1. The value 0 means that your character is currently alive. If the value is 1, then that means your character is dead (if you load this save, a corpse will be lying at your feet in town), in which case 12 bytes of (unknown) data will follow, after which there will be another items list header (the one with the identifier "JM" and item count) and item list for items on your corpse. Sadly, the meaning of the 12 bytes is unknown.

If you have an Expansion character, then the corpse item list (if there is one) will be followed by the 2-character identifier "jf". If and only if you have a mercenary (alive or dead), this header is followed by an item list header and (possibly empty) item list containing items equipped on the mercenary. This item list is followed by the 2-character trailer "kf".

If you have a necromancer, it is possible for you to have an Iron Golem that is preserved when your game is saved and restored. The Iron Golem is based on an item. Following the mercenary item list, there will be a single byte that is 0x00 if there is no golem, or 0x01 if there is. If there is a golem, this byte is followed by a single item.