01The three numbers

Every download command is built from three IDs, nested inside each other:

App ID — the game itself (e.g. Team Fortress 2 is 440). Feeds -app.
Depot ID — one bucket of the game's files. A game is split into depots: base content, per-platform binaries, language packs, DLC. Feeds -depot.
Manifest ID — a specific version of one depot: the exact file list at one point in time. This is what pins the version you want. Feeds -manifest.

The home for all three is SteamDB — a community database that exposes Steam's content structure that the store hides. (If you only need the current version, you don't need any of this; this lookup is for choosing a specific older one. The concepts behind these terms live in the glossary; this page is purely how to look them up.)

02Finding the App ID

The easiest of the three — it's the game's number, and there are several ways to read it:

Store URL — open the game's Steam store page; the number in the address is the App ID: store.steampowered.com/app/440/.
In your library — right-click the game → Properties → Updates lists the App ID; or Browse Local Files and look at the appmanifest_440.acf filename in steamapps\.
SteamDB search — search the game's name at steamdb.info; the App ID is on its page. This is the way for a game that's been removed from the store (no store URL to read), since SteamDB keeps the page.

Once you have the App ID, the canonical page is steamdb.info/app/<appid>/ — everything else hangs off it.

03Finding the Depot ID — and picking the right one

On the game's SteamDB page, open the Depots tab. You'll see a list, and the question is which one(s) you need. The patterns:

SteamDB's Depots tab for an app, listing each depot with its ID, configuration (Windows, 64-bit, Shared Install) and size. — **The Depots tab on SteamDB.** Each row is a depot, with its ID, configuration and size — here depot 261551 (Mount & Blade II: Bannerlord, 44 GB) is the base content. Frame from the tutorial "How To Downgrade Any Game from Steam — DepotDownloader" by Taylor_MB (YouTube).

Base content — usually the depot named after the game, the largest one. For many games this single depot is the whole download.
Per-OS binaries — some games split the executable into Windows / macOS / Linux depots (Team Fortress 2's 232251/232252/232253). Take the one for your platform plus the shared content depot.
Languages — separate depots per language; only needed if you want a non-default language (see OS & language).
DLC — each DLC (and many soundtracks) is its own depot, which is how you can download just one piece (see selective downloads).

Rule of thumb when unsure: pick the depot with the game's name and the biggest file size — that's the base content. If the game uses several depots for one version, you'll feed them all (DepotDownloader takes a list of depots and a matching list of manifests). Note also the branch/beta column — a depot may carry separate public and password-protected branches; the version you want might live on one of those (the glossary defines branches). Click a depot to open steamdb.info/depot/<depotid>/.

04Finding the Manifest ID — the version step

This is the one that actually pins the version. From the depot's page, open its Manifests tab (steamdb.info/depot/<depotid>/manifests/). You'll see a chronological list: each row is a manifest — one snapshot of that depot — with a date and a long Manifest ID number.

SteamDB's Manifests tab for a depot, showing a dated list of 'Previously seen manifests' — each row a version with its Manifest ID and branch. — **This is what the Manifests tab looks like** — depot 261551 (Mount & Blade II: Bannerlord), one dated row per version, Manifest ID on the right. Frame from the tutorial "How To Downgrade Any Game from Steam — DepotDownloader" by Taylor_MB (YouTube).

SteamDB labels manifests by date, not by version name, so the workflow is:

Find out when the version you want shipped — the game's patch-notes history (SteamDB has a Patchnotes tab; the game's wiki usually lists update dates too).
On the Manifests tab, find the row whose date matches that update (take the manifest dated on or just before the version you're targeting).
Copy the Manifest ID from that row. That's your -manifest value for this depot. If you're downloading several depots, grab the same-date manifest from each.

Sign in to see older history SteamDB only shows the most recent manifests to anonymous visitors — roughly the last year. To see further back, sign in to SteamDB (it's a free login through your Steam account, read-only — SteamDB never gets your password). Older builds simply won't appear in the list until you do. A pro shortcut on the Patchnotes tab: open the patch after the one you want and look at the changed files — the crossed-out manifest shown there is the previous build's, i.e. exactly the version you're rolling back to.

05Build ID vs Manifest ID — don't grab the wrong number

The single most common mix-up. SteamDB shows two kinds of version number, and DepotDownloader wants only one:

	Build ID	Manifest ID
What it is	A global, ever-incrementing number for the whole app, bumped on every patch.	A snapshot of one depot at one point in time — the actual file list.
Where on SteamDB	The Builds tab (app-level).	A depot's Manifests tab (per-depot).
Relationship	One build = a set of manifests, one per depot. The build is the patch; the manifests are its pieces.
DepotDownloader uses	✗ — not accepted.	✓ — this is the `-manifest` value.

So if you copied a number from the Builds tab and the command rejects it, that's why: you need the Manifest ID from a depot's Manifests tab, not the Build ID. The mistake I made the first time was grabbing the tidy Build ID off the Builds tab and feeding it straight to -manifest — it bounced, and it took me longer than I'd admit to realize I was on the wrong tab entirely. The Builds tab is still useful — it's a clean way to read patch dates and see which build is which — but the number you feed the tool comes from the Manifests tab, per depot.

06Putting it together

With the three IDs in hand, the command writes itself — App ID once, then depot/manifest paired up (one manifest per depot, in the same order):

> .\DepotDownloader.exe -app <appid> -depot <depotid> -manifest <manifestid> \
    -username you -remember-password -dir .\my-build

For a multi-depot version, the lists pair one-for-one: -depot 441 232251 -manifest <m-441> <m-232251>. The full workflow around this — installing the tool, logging in, and what to do with the files afterward — is in the universal downgrade guide and after the download. And if the manifest you picked is refused with "no manifest request code," that's not a lookup mistake — it's Valve gating the old manifest, a separate issue.