Always backup your original saves, disable Steam Cloud during installation, and only download from trusted communities.
Installation varies slightly depending on your platform, but the process generally involves replacing files in your local save directory. 1. Locate Your Save Folder Reddit·r/BatmanArkhamhttps://www.reddit.com
A special note on safety. Searching for "batman arkham knight 240 save file pc" on YouTube will lead to dozens of videos with links in the description. Many of these are:
Provides a reliable 240% Save Mod that includes all DLC content.
100% Main Story & Most Wanted side missions (including all 243 Riddler trophies).
If you're playing on Steam, you can also use the Steam Cloud to sync your saves. Ensure that Steam Cloud is enabled for Batman: Arkham Knight in your Steam settings (Library > Right-click Batman: Arkham Knight > Properties > General > Enable Steam Cloud synchronization for Batman: Arkham Knight).