Installation Instructions
Java is required for use of this program and we recommend using Adoptium 17 for current and future versions for best results. Starting with the 0.50.0 development release, it will be required.
MegaMek should run on any computer that can run Java without much issue. Will NOT run on iOS/iPadOS/tvOS/Android devices. You experience will vary based on computer specifications.
Instructions for Windows and macOS are available.
Updating Between Versions
CRITICAL: Always extract each version to its own folder — never unzip a new version over an old one (e.g., don't extract 0.50.11 into your 0.50.06 folder). Overwriting will corrupt saves and campaigns. Campaigns are also NOT backward compatible; if a newer campaign opens in an older version, consider yourself lucky.
Follow these steps to protect your MekHQ campaign data:
- Back up your campaign and custom files — critical to prevent data loss
- Extract the new version to a fresh folder — never overwrite the old installation
- COPY (don't move) your campaigns and custom data to the new folder
- Do NOT copy MegaMek saves or preference files between versions
- Re-save custom presets to update them for the new version
For those of us using macOS, there are some additional things that we need to be aware of. We're making this more prominent in hopes to reduce the number of questions we get that can be solved by going here.
Make sure Adoptium 17 is installed. Recommended way is in the link above.
Make sure the decompressed files are NOT in the Documents, Downloads, or Desktop folders. These are protected folders and macOS will not let it run.
To run the programs from Windows, just double-click on the given program icon from within the folder you unzipped.
Depending on how Java is setup on your machine, you may also be able to double click on the JAR files themselves vs the EXE. No real difference between the two other than possible launching experience.
DO NOT USE THE BUILTIN UTILITY FOR DECOMPRESSING ZIP FILES! We recommend using 7-Zip.
The Unix/Linux releases do not include application binaries, but you can run the programs directly from the included JAR files. On some desktops, you may just be able to double-click these JAR files in order to run the programs. you can also run the programs (MegaMek, in the example below) from the command line with the command:
java -jar MegaMek.jar &We recommend that most users download and use the milestone version of the programs to minimize issues with bugs. The development versions are only for those users interested in testing and bug hunting new features.
To install the programs, unzip the download into the directory of your choice. To run the programs follow the platform specific instructions below.
On Windows, do NOT use the built in utility for decompression zip files as it has been known to cause issues. We recommend using 7-Zip.