verifiednote 0001build 66792026-08-15vpklayout

VPK archive layout and inventory

Question

How is Deadlock's content packaged on disk, and where in that packaging does gameplay data live relative to everything else?

Summary

Deadlock's internal name is Citadel. The game mount is citadel/; shared engine content is core/.
All shipped content is in citadel/pak01_*.vpk — 274 archives, 27.4 GiB, indexed by a single pak01_dir.vpk holding 130,730 entries.
The archives are VPK version 2. The directory tree is nested extension → directory → filename, which a ~40-line stdlib parser can read without extracting anything.
Gameplay data is a rounding error in the payload: 85 .vdata_c files totalling 0.8 MB against 24 GB of textures and 2.9 GB of sound.
Localization does not live in the VPKs — it is loose .txt on disk. See note 0004.

Findings

Top-level layout

game/
  bin/win64/deadlock.exe, vconsole2.exe
  citadel/                 the game mount
    pak01_000.vpk .. pak01_273.vpk    content archives
    pak01_dir.vpk                     the index (6.6 MB)
    shaders_pc_*.vpk, shaders_vulkan_*.vpk
    resource/localization/            loose .txt, NOT packed
    gameinfo.gi, steam.inf
  core/                    shared engine content (6 archives)
  citadel_<lang>/          per-language overlay, one small VPK each (~19 MB)

citadel/gameinfo.gi confirms the mount name and lists 17 supported languages. English is not among the citadel_<lang>/ overlay directories — it is the base content.

Content inventory (citadel/pak01_dir.vpk)

count	size	extension	what
79,305	2,903.1 MB	`.vsnd_c`	sounds
15,569	52.1 MB	`.vpcf_c`	particles
12,864	23,987.2 MB	`.vtex_c`	textures
9,372	122.1 MB	`.vnmclip_c`	animation clips
5,013	825.7 MB	`.vmdl_c`	models
3,949	16.9 MB	`.vmat_c`	materials
427	4.6 MB	`.vcss_c`	Panorama UI stylesheets
419	1.1 MB	`.vxml_c`	Panorama UI layouts
110	2.1 MB	`.vrr_c`	response rules (VO logic)
85	0.8 MB	`.vdata_c`	gameplay data
29	0.4 MB	`.txt`	loose config

Top-level directories: sounds (79,304), models (22,931), particles (15,686), materials (6,414), panorama (3,449), scripts (203), stats (6).

Inferred: anyone after gameplay data should filter to scripts/ + .vdata_c and ignore 99.9% of the archive by volume. Extracting the whole pak is never necessary for this goal.

VPK v2 directory format

Header is signature:u32 = 0x55AA1234, version:u32, treeSize:u32, followed in v2 by four section-size u32s (file data, archive MD5, other MD5, signature) — so the tree starts at byte 28.

The tree is three nested runs of null-terminated strings, each run ended by an empty string: extension → directory → filename. Each filename is followed by a 18-byte footer:

crc32:u32  preloadBytes:u16  archiveIndex:u16  entryOffset:u32  entryLength:u32  0xFFFF:u16

then preloadBytes of inline data. A directory of " " (single space) means the archive root. archiveIndex selects which pak01_NNN.vpk holds the body.

The per-entry crc32 is what makes cross-patch diffing cheap — see the --manifest flag.

Reproduce

python tools/find_game.py
python tools/vpk_list.py
python tools/vpk_list.py --prefix scripts/ --ext vdata_c --list

Expected head of find_game.py at this build:

ClientVersion   6679   <-- verified_against
SourceRevision  10912166
VersionDate     Aug 14 2026
archives        274 pak01_*.vpk  (27.4 GiB)

To diff content against a later patch:

python tools/vpk_list.py --manifest > manifests/6679.txt
# after patching:
python tools/vpk_list.py --manifest > manifests/NEXT.txt
diff manifests/6679.txt manifests/NEXT.txt

Gotchas

pak01_dir.vpk alone is not enough to extract. It is only the index; bodies live in the numbered archives, so all 274 must be present. Reading the listing, however, needs only the dir file — that is why vpk_list.py is fast.
Sizes in the index are the compiled sizes. Decompiled output is much larger: abilities.vdata_c is 485 KB packed and 7.0 MB as text.
core/ has its own pak01 set. Do not assume a path is in citadel/ — engine-level assets resolve from core/.
Archive counts change every patch. 274 is a fact about build 6679, not a constant.

Open questions

Not checked: whether citadel_<lang>/ overlay VPKs contain anything beyond localized audio, or whether any gameplay data differs per language.
Not checked: shaders_*.vpk contents at all.
Not checked: whether --vpk_verify checksums pass on this install.
The .sofa (43.2 MB) and .dat entries were seen in the index but not inspected.

Sources

VPK file format — Valve Developer Community) (format description; the layout above was independently confirmed by parsing this install)