Infocom game module for Z-machine version 3
File type: Game file
A z3 file is an Infocom story file containing compiled game code for version 3 of the Z-machine.
The file can be played with a compatible Z-machine interpreter, including Frotz for Microsoft Windows.
Found 2 different file type records with the same z3 filename suffix.
File type category:
Game file
Date updated: October 30, 2026
Infocom used the Z-machine as a virtual machine for its text adventure games. A z3 file contains Z-machine instructions and the other game data required to run a story, so it is also called a story file or Z-code file.
The number in a Z-code filename identifies the Z-machine version for which the file was intended. Common extensions include .z3, .z5 and .z8; .z1, .z2, .z4, .z6 and .z7 are extremely uncommon, and some files use .dat instead.
Most Z-machine files are version 3, 5 or 8. Version 6 adds support for some graphics. Interpreters for these files have been released for many platforms, including older computers such as the Apple II, TRS-80 and Sinclair systems, portable systems such as Palm OS devices and the Nintendo Game Boy, and modern desktop platforms.
The format remains in use for playing preserved Infocom games and other interactive-fiction story files. Frotz is one of the interpreters that can run version 3 files on Microsoft Windows.
Install Frotz on Microsoft Windows, then open the z3 file from the interpreter or associate the file with Frotz. The program should load it as a Z-machine story file.
Other Z-machine interpreters can also open version 3 story files on supported platforms. If an interpreter does not recognize the .z3 extension, use its command to open a story file manually.
A z3 file is a playable story file rather than a document format, so it normally has no useful conversion to another file type.
It can be run in an interpreter that supports Z-machine version 3. Creating a different Z-code version requires the game's source and an appropriate authoring tool; simply renaming the extension does not convert the file.
Software applications that handle other tasks involving z3 files:
Microsoft Windows
File type category:
Various data file
Date updated: February 28, 2019
The z3 file extension is associated with ZoneAlarm, a personal firewall software, originally created by Zone Labs and currently developed by CheckPoint Software Technologies LTD.
One of ZoneAlarm features is MailSafe, which detects e-mail attachments and warns the user about their presence. When a potentially dangerous attachment is detected, the program quarantines the file with simple renaming of its original file extension, so it breaks the common program association function in Windows and prevents such files from being executed (or launched via associated program).
A file with z3 file extension had its original file extension renamed for security reasons.
Probably not meant to be accessed by the user.
Probably cannot be converted to anything else.
Software applications that handle other tasks involving z3 files:
Microsoft Windows
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