MistriaGuide

Third-party modding guide

Fields of Mistria mods and MOMI setup

Use the mod author’s requirements as the authority, install one change at a time, and expect to rerun the installer after game updates.

Sources checked August 9, 2026.

The short answer

Download the operating-system build from the MOMI files page. On Windows, create a folder named mods in the Fields of Mistria directory beside data.win. On Steam Deck or another Linux system, use a mods folder in the game directory or a mistria-mods folder in your home directory. Extract compatible mods into that folder, run MOMI, and choose Install. These locations and steps come from the installer author’s MOMI documentation.

A cautious installation checklist

  1. Back up first. Keep a copy of important saves and any original files you would need to restore. A backup is a precaution, not proof that a mod is compatible.
  2. Read the mod page. Confirm its supported game version, MOMI dependency, minimum installer version and any other requirements. MOMI’s documentation says each mod must be updated for its format; compatibility is not automatic.
  3. Download from the source. Use the mod author or its Nexus page. Avoid reuploads whose contents and version cannot be verified.
  4. Extract the mod correctly. The author’s docs say MOMI cannot install a mod left as a .zip. The mod folder should sit directly in the mods folder and contain its manifest.json, rather than being wrapped in an extra folder.
  5. Install one mod at a time. Launch the game between additions. That is our troubleshooting recommendation: it narrows the likely cause if the game stops launching or content does not appear.

Windows location

Create mods inside the game directory, next to data.win. If MOMI cannot detect the game, the documentation suggests placing the installer in that same directory beside data.win. Do not move or rename unrelated game files to make a mod work; recheck the mod’s instructions instead. The exact directory can vary with where Steam is installed, so this guide does not invent a universal drive path.

Steam Deck and Linux locations

The MOMI author documents two choices: a mods folder inside the game directory, or mistria-mods in the user’s home directory. Use the current Linux package shown on the installer files page, and verify that a particular mod supports the same installer and game version. A folder being detected does not itself prove the mod will work.

After a Fields of Mistria update

Run MOMI again after the game updates; that instruction is explicit in the installer documentation. Before reinstalling a full set, recheck the installer files and every mod page for new versions or dependencies. If the game no longer launches, one community mod author documents a recovery sequence: use MOMI to uninstall all mods, use Steam’s Installed Files screen to verify game-file integrity, then reinstall compatible mods with MOMI. Treat that as a community recovery example, not an official guarantee or a universal repair.

For vanilla lookup while mods are disabled, use the crop and forageable guide, the museum tracker, or the romance guide. The site data status describes the game snapshot used by this fan site; it does not certify mod compatibility.

Antivirus messages and safety limits

Some tool authors may describe a security alert as a false positive. That is only the author’s explanation, not proof that a file is safe. Do not disable security software merely because a page says so. Verify that the download came from the expected author page, compare the listed version and requirements, and stop if the source or behavior is unclear. This guide cannot audit executable files or guarantee any third-party download.

Sources

Checked August 9, 2026. Third-party tools can change quickly; recheck their own pages immediately before downloading.