League File Formats

Byte-level specs live on the LeagueToolkit wiki — that's the authoritative source and the one that keeps up with Riot's version bumps. This page is a local lookup: which file is parsed by what in our tree, and what bites us in practice.

If you want to decode a real skin's contents without running anything, fetch the CDragon bin.json instead of reading raw bytes.

Parser map

Format	Purpose	Our parser
WAD	Archive wrapping every game asset	OfficialLeagueToolkit/Core/Wad/WadFile.cs; wrapped by LeagueConvert/IO/WadFile/StringWad.cs
BIN (PROP / PTCH)	Typed property container — dominant config format	OfficialLeagueToolkit/Core/Meta/BinTree.cs + LeagueConvert/IO/PropertyBin/
SKN	Skinned mesh	OfficialLeagueToolkit/Core/Mesh/SkinnedMesh.cs → LeagueConvert/IO/Skin/Skin.cs
SKL	Skeleton	LeagueToolkit/IO/SkeletonFile/Skeleton.cs (our fork with the track-mapping logic)
ANM	Animation	LeagueToolkit/IO/AnimationFile/Animation.cs (our fork)
TEX	Native texture	OfficialLeagueToolkit/Core/Renderer/Texture.cs
Ritobin	Text form of BIN	OfficialLeagueToolkit/Toolkit/Ritobin/RitobinWriter.cs — used by --dump-materials

We don't currently parse MapGeo, WGEO, SCB/SCO, or the various legacy formats (INIBIN, AiMesh, MOB, etc.). If you need to, the upstream library has them — see legacy formats.

What bites us

WAD

• PBE WADs change daily. WadDownloader.cs clears the PBE cache before each download — don't add blanket caching on top.
• Our old docs listed only three compression types. The full set is None / GZip / Satellite / Zstd / ZstdChunked. Satellite is rare but valid — data lives in a separate file, not inline.
• Unresolved chunk paths render as hex (0xDEADBEEFCAFEBABE). Log and skip; don't crash.

BIN

• Animation clip mEventDataMap is a BIN map keyed by metaclass hash. Hash 3049371309 = JointSnapEventData — that's what drives the joint-snap bake (see skeletons & animations).
• Shader params show up as hex keys in --dump-materials when the property name isn't in hashes.binhashes.txt. Nothing's broken — the dictionary is just incomplete for that name.

SKN

• v0.1 skins carry a single implicit submesh called "Base". Don't assume multi-submesh when walking ranges.
• A vertex's bone index is not a joint index. It's an index into the skeleton's influence list, which in turn holds the joint index.

SKL

• ELF hash is case-insensitive. When a skeleton carries both Head (real, in Influences) and head (lowercase stub parented to root, bind translation canceling the root), the two hash to the same value. The two-pass match in MapAllTracksInOrder is the reason it works. Don't collapse it into one pass — see the Shaco case study if you're tempted.
• SkeletonJoint.GlobalTransform and InverseBindTransform are coupled — setting one recomputes the other. Don't hand-roll either side.

ANM

• Uncompressed r3d2anmd readers used to leave Duration = 0 (only FrameDuration was set). We compute Duration = frameCount × FrameDuration explicitly now. The joint-snap bake silently skips animations with Duration == 0.
• One .anm can be referenced by multiple clip names (Garen's Recall and Recall_Base share a file). When rewriting tracks in a bake, dedupe by Animation instance or you'll mutate twice.
• mStartFrame / mEndFrame in JointSnapEventData are in 30 Hz ticks. Our bake samples at 60 Hz. Keep SnapFrameRate = 30f / SnapSampleRate = 60f in sync with that.

TEX

• The engine also accepts DDS. Don't assume every texture is .tex.

See also

• Hashing algorithms — which hash family applies where.
• CDragon bin.json — decoded per-skin data without running the extractor.
• Skeletons & animations — the heaviest format-handling code in the repo.
• LeagueToolkit wiki index — curated tour of the upstream docs.