Which story file formats does Planedrift support?

Updated

Planedrift plays story files ending in .z3 — the Z-machine version 3 format used by most classic Infocom releases. You can open a .z3 file you already have, or resume a previous game, and the site also offers Zork I, II, and III ready to play. For anything beyond those three, you need to supply your own .z3 file.

What the .z3 format means in practice

Infocom's games were built for the Z-machine, a virtual machine with numbered versions. Version 3 covers the bulk of the 1980s catalog, which is why Planedrift standardizes on it. The practical consequence: a story file from a later Z-machine version (v5 or v8, for example) is not something the site claims to run. If you are unsure what you have, the file extension is the quickest signal — Planedrift's own wording is that it "plays story files ending in .z3."

Where to find compatible games

Planedrift points to the Obsessively Complete Infocom Catalog as the archive for the rest of Infocom's 1980s output. The site specifically recommends looking for the Masterpieces of Infocom releases, because those are the versions Planedrift is tested against. That testing note matters: a .z3 file from an untested source may load but behave unexpectedly, whereas the Masterpieces releases are the known-good baseline.

Opening a file or resuming a game

  1. Get a .z3 story file onto the device you're browsing from — from the catalog above, or a copy you already own.
  2. Use the "Bring your own" option on the site and open the file.
  3. To continue later, use the resume path for a previous game rather than re-opening the file.

Expected result: the story starts in the browser, with auto-saves and rewinds available as you play. The common snag is a file that isn't .z3 — check the extension before troubleshooting anything else.

What you get around the game itself

The player is built for short, unhurried sessions: light and dark themes, readable fonts and colors, auto-saves and rewinds, a searchable transcript, and the ability to capture to-dos while you play. Those features apply to any .z3 file you load, not just the bundled Zork titles.

If your goal is simply to try the format, start with Zork I — it's playable without sourcing a file. If you want a specific Infocom title, confirm it's a .z3 and prefer a Masterpieces of Infocom release before loading it.