The Vestra Forge — Modding Vestra Coda

The one rule everything else comes from

A mod may change how the world looks. It may never change what a player can perceive.

You cannot cheat by modding, and we're not worried that you'll try. The server owns every piece of game state — retexture a copper sword as a dragon blade and the server still swings a copper sword. What we guard is information: seeing through what should hide you, hearing what shouldn't be audible, or reading a fight the game didn't mean to show you. That's the whole of it.

What you can and can't build

Go ahead

Armour, clothing and weapon appearance
Creature and mount appearance
Props, furnishings and environment dressing
Ambient audio and musicCreature ambience and footsteps, not combat cues
HUD skins — move, resize, recolour, fade or hide any HUD elementOne JSON document, validated before you ship it
Dye and tier variantsData only — no new textures needed

Not allowed

Changing an object's readable silhouette or size past the allowed delta
Making things invisible or transparentFoliage, effects, telegraphs, other players
Touching combat audioWind-ups, telegraphs and ability cues stay as shipped
Shader source of your ownYou get our templates and their uniforms
Widgets reading party, target or combat-log data
Anything that sends input on the player's behalfNo exceptions, ever
Executable code in any formNo scripts, no packs, no binaries — the loader won't take them

The validator is the authority, not this page. Run vcforge check ./my-kit before you upload and it will tell you exactly what passes. It's the same code our servers run, so its answer is final in both directions — if it passes on your machine, it passes on submission.

NPCs aren't moddable yet. Unlike creatures, NPCs have no single mesh — they're assembled from the character rig at runtime, so there's nothing for a Kit to replace. They'll appear in the target catalogue once the appearance system exposes targets of its own. Creatures, which do have meshes, are available now.

Why interface mods only see your own character

Available now: HUD skins — a declarative document that moves, resizes, recolours, fades or hides the elements the HUD already has. No code, and no game data involved, so there is nothing to gate.

Not yet built: scripted HUD widgets that read live game data. When they arrive they will run in a sandbox fed by a published bus, and that bus will carry your character and nothing else. We are publishing the shape of that decision now so nobody builds a plan around data we are not going to expose.

Data	When built	What it would let you build
Your character Resources, cooldowns, buffs, your own damage	Planned	Custom bars, buff timers, rotation helpers, personal damage readouts
Your party Member health, resources, buffs, positions	Not published	Healer frames, dispel trackers, raid frames
Your target Health, cast bars, telegraph timings, threat	Not published	Boss timers, threat meters
Combat log Itemised damage and healing for everyone	Not published	Damage meters, parses, external log sites

The honest reason: fields can be added to that bus and can never be taken away. The day boss timers and damage meters exist, every encounter we design afterwards is tuned on the assumption that you have them — and that decision cannot be walked back. So we're starting narrow on purpose, watching what people actually build, and we'll widen it when we're confident rather than when it's tempting.

One consequence we accept: party and raid frames are our job, not yours. If ours aren't good enough, that's a bug report we want to receive — and you can always reskin them.

Shaders, and why you get templates

You supply uniform values against shaders we've written. You don't ship shader source.

This isn't a judgement about you. It's that a texture genuinely can't see through a wall and a shader genuinely can — switch off depth testing, raise a render priority, and you have an x-ray view built entirely out of "cosmetic" code. There is no validator rule that reliably separates a stylish shader from that one. Templates are how we say yes to the first thing without accidentally saying yes to the second.

If a template can't do what you're after, ask. Adding a uniform is easy, and we'd far rather extend the templates than watch people give up.

Colour comes from the palette, not from you

This surprises most artists, so read it before you start painting: your texture doesn't carry colour at all.

A Vestra Coda texture stores a zone identifier, lightness, ambient occlusion and flow. Colour is resolved at render time from the game's palette. So you paint structure, material and wear — the things that actually make an asset read — and the world's colour scheme applies itself to your work.

Two things follow from that. Your work is automatically in style, because the format cannot express an off-palette colour even if you wanted it to. And dye and tier variants are almost free — a handful of lines of data, no second texture. Ship one asset, get the whole variant family.

Eight zones, hard limit. Nine will fail validation. It isn't arbitrary: past eight, block compression puts visible speckling along every region edge. The exporter presets keep you inside it without having to think about it.

The toolkit ships with the palette and export presets for Blender and Substance. Start from those rather than fighting the format.

Limits

Every Kit has budgets. They exist because a client that stutters or crashes with mods installed generates bug reports against the game, and because one person's 16K texture set shouldn't cost everyone else their frame rate.

Texture size: Per-texture dimension ceiling
Texture count: Per Kit, and per installation
Video memory: Total across enabled Kits
Triangles: Per replaced mesh
Silhouette delta: How far bounds may move from the original
Alpha coverage: A floor, so nothing vanishes
Emissive: A ceiling, so nothing becomes a beacon
Zones: Eight, no exceptions

Current values live in the validator and are published with each API version. Don't work from a number you read somewhere — run vcforge check, which always knows.

Where your assets came from

Every asset in a Kit needs a provenance declaration: you made it, you licensed it and can produce the receipt, it's under a permissive licence you've attributed, or it's AI-assisted and you've said how.

We ask because we can't tell by looking. A texture ripped from another game and a texture painted last Tuesday are the same file to a validator. If something ships in the real game and turns out to belong to someone else, it comes out of the game, any payment comes back, and the person who has a genuinely terrible week is you, not us. The declaration is what lets us take your work seriously without having to take it on faith.

Nothing is ever integrated straight from an upload. Anything selected for the game goes through a quarantine period and an audit pass first.

Publishing a Kit

Build your Kit and run vcforge check until it comes back clean.
Pack it with vcforge pack. You get a single .forge file — an ordinary signed archive you can open and inspect yourself.
Upload it to mod.io, which is the Forge's main home. Nexus works too, and Vortex will install .forge files natively.
We validate and sign it, and the game will not load an unsigned Kit. That isn't there to control you — it's the mechanism that lets us promise every player that no mod grants an advantage, and that promise is what this whole programme rests on.

Seasons and selection

Each season has a theme tied to what we're actually building — "light armour and fishing gear for the Ashfall Coast", that sort of thing. Two tracks run in parallel, and they are genuinely different things.

Player's Choice

Voted in-game, one vote per account with a playtime minimum, which is how we keep it from being decided by whoever has the most alternate accounts or the largest audience. It wins a title and real bragging rights. It carries no promise of integration — and we'd rather say that plainly now than disappoint someone later.

Forge Selection

Chosen by a studio jury against a rubric we publish before the season opens. This is the one that ships. We post reasoning for the winners and for the near-misses, because losing is fine and not knowing why isn't.

Winners sit out the following season. It isn't a punishment — it's so the same three names don't own the Forge forever.

If your work ships

Attribution: "Forged by <your name>" in the item's description, in the live game, permanently. We think this is worth more than anything else on this list.
Title: Forge Master, wearable on your character and shown on your account.
Monument: Your name carved into the Forge monument in the world, alongside everyone else whose work made it in.
Free content: If it ships free to all players, there's no payment — and we'll tell you that before you agree to anything.
Paid content: If it goes into the store, you choose: a flat fee, or a share of what players spend on it.
Paperwork: You'll sign a real agreement covering your identity and a warranty that the work is genuinely yours. Real money means real paperwork.

Rejections, appeals and changes

A rejection names the rule and the asset. If it's a budget, it gives you the number you hit and the number you needed. "Doesn't feel right" is not a rejection reason we will ever send you.

You can appeal, a person reads it, and you get an answer with reasoning attached. Sometimes the appeal is right and the rule changes.

The version promise

Your Kit declares which API version it targets. We support the current version and the two before it, and deprecations are announced ahead of time — never in a patch note on the day. Override targets are a contract; we don't rename them casually just because the code underneath moved.

When these rules change

This rulebook is versioned and changes are announced. Where a rule is a number, the validator is always the current truth — this page explains the thinking, vcforge check gives the answer.

Submitting a mod

Before your first submission you'll be asked to read and accept the Creator Terms. They cover who owns what, what happens if we integrate your work, and what you're promising us about where your assets came from. We record which version you accepted and when.

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