Can I get an Arcana for free this way?

You can make your client draw one for you. Nobody else sees it, it never enters your inventory, and it has no value. That is the honest description of what the unlock is.

Will Valve take the items away?

There is nothing to take. Your account is unchanged; the difference is a text file on your disk. Verifying your game files in Steam undoes it.

Do my unlocks survive a Dota update?

Not by themselves. A patch rewrites the files that carry the change. The app checks on startup and restores what the update removed.

Free cosmetics, and what they really are

Every cosmetic in Dota is already on your disk. Your client checks a list to decide which ones to show you. Edit your copy of the list and it shows you more.

Checked4 September 2026

The list

When Valve adds an Arcana, the models and sounds go into the game files for everybody. What separates you from somebody who bought it is scripts/items/items_game.txt, a text file listing every item in the game and what it belongs to. Your client reads that file to decide what to draw.

Change your copy and your client draws differently. The server keeps its own record of what you own, which is why the whole thing is one-sided: the courier walks across your screen and nobody else's.

What that gets you

Dota 2 Mod Manager reads the item table out of your game files rather than shipping a list of its own, so anything Valve adds in a patch appears without waiting for an app update.

Weather effects, which is the one most people come for.
Couriers, wards and their upgrades.
Loading screens, emblems and menu backgrounds.
Announcers and mega-kill packs.
Terrains, river paints and tree styles.

What it does not get you

Anything the server decides stays with the server. Your Steam inventory does not change, nothing becomes tradeable, and no item you unlock this way is worth anything to anyone. Battle pass levels, Dota Plus features and anything counted on Valve's side are out of reach by construction, not by politeness.

Hero sets are the case people misread most. A local unlock shows the set to you, and your opponents keep seeing the default hero. If the point was for other people to see it, this is not the thing.

Why it needs a search-path patch

The item table lives behind the MOD search path, and Dota resolves MOD to game\dota alone. A file in a language folder never reaches it, which is why unlocking cosmetics takes more work than installing a skin.

Registering another content folder means editing game\dota\gameinfo_branchspecific.gi and then adding the edited file's hash to game\bin\win64\dota.signatures, which the client verifies at startup. The app backs up both files before its first write and puts the originals back byte for byte when you undo it. The search paths in detail.

Dota patches overwrite both files regularly. Anything that edits them has to notice and redo the work, or your unlocks quietly disappear after an update. What to do when that happens.

Questions

Can I get an Arcana for free this way?: You can make your client draw one for you. Nobody else sees it, it never enters your inventory, and it has no value. That is the honest description of what the unlock is.
Will Valve take the items away?: There is nothing to take. Your account is unchanged; the difference is a text file on your disk. Verifying your game files in Steam undoes it.
Do my unlocks survive a Dota update?: Not by themselves. A patch rewrites the files that carry the change. The app checks on startup and restores what the update removed.