MW5 Save → JSON

A lite, heuristic tool to peek inside MechWarrior 5: Mercenaries save files (.sav) and dump a best-effort JSON view. It’s intended to help you locate values of interest in otherwise opaque binary data.

Typical things you might search for in the output:

• AvailableCBills
• StartingDateTicks (start date of the campaign or career)
• ExecutionDate (next payment due date, found after a path that looks like /Game/Campaign/TimelineEvents/FinanceEvent/FinanceEvent.FinanceEvent_C)
• TotalTimeElapsed (days elapsed in the game)
• Various flags, enums, Guids, and object paths

Note: This is not a full or authoritative parser. It trades completeness for simplicity and speed.

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What it does

• Scans the save file for recognizable UnrealEngine-ish property markers and nearby keys.
• Heuristically decodes common scalar types (int32/int64, float/double, boolean) and string-like data (paths, quoted text).
• Attempts to interpret .NET-style DateTime “ticks” and present a human-readable ISO timestamp where found.
• Outputs a JSON file alongside your .sav for convenient searching and inspection.

The JSON structure is a best-effort tree of keys and values; when keys repeat, you may see lists. Some sections may appear nested (arrays/maps/struct-like blocks), but the shape is not guaranteed to mirror the exact in-game object model.

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Limitations and caveats

• This is a rough viewer: some data types may not be decoded correctly.
• On large saves, some content may be missing in the output JSON due to recursion and list-size limits intended to prevent runaway processing.
• Keys are discovered heuristically; names may be missing, repeated, or partially recovered.
• Numeric fields may occasionally be misread depending on local context.
• Arrays and maps are approximated; ordering and grouping are not guaranteed.

If you can’t find a value, try searching for multiple related keys or alternate spellings.

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Requirements

• Python 3.12+ (earlier versions may work but haven't been tested)
• No third-party dependencies (standard library only).
• A virtual environment is recommended for isolation but not required.

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Usage

1. Optional: create and activate a virtual environment.

   • Windows (PowerShell)
     • python -m venv .venv
     • .\.venv\Scripts\Activate.ps1
   • macOS/Linux (bash/zsh)
     • python3 -m venv .venv
     • source .venv/bin/activate

2. Run the script and provide the path to your .sav when prompted:

   • Windows
     • python mw5_save_to_json.py
   • macOS/Linux
     • python3 mw5_save_to_json.py

3. The tool writes a .json file next to your .sav with the same base name.

Example:

• Input: C:\Users\You\Saved\Save_001.sav
• Output: C:\Users\You\Saved\Save_001.json

Open the JSON in your favorite text editor and search for keys like AvailableCBills, StartingDateTicks, ExecutionDate, or TotalTimeElapsed.

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Tips for searching

• Monetary: AvailableCBills
• Campaign start time: StartingDateTicks
• Next payment due date: ExecutionDate, found after a path that looks like /Game/Campaign/TimelineEvents/FinanceEvent/FinanceEvent.FinanceEvent_C
• Days elapsed in the game: TotalTimeElapsed
• General time fields: any key with “Ticks” often indicates a .NET tick count (100 ns) since January 1, 0001

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Editing your save (advanced)

If you want to make direct changes to the save file, consider using a hex editor (for example, HxD on Windows). Tips:

• Always make a backup of your save before editing.
• Use the JSON output to locate nearby keys/values, then search for those byte patterns in the .sav.
• Be mindful of endianness and data sizes; modifying lengths or structure can corrupt the file.
• Make small changes and test incrementally.
• There is a nice video on YouTube that can show you how to edit MW5 save files with a hex editor.

Editing is entirely at your own risk.

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Troubleshooting

• JSON is missing large chunks:
  • Very large or deeply nested sections may be truncated by built-in depth and list-size limits. Try searching the original save file using a hex editor.
• Values look wrong:
  • Heuristics can misinterpret ambiguous byte patterns. Cross-check with multiple occurrences or related fields.
• Nothing useful appears:
  • Ensure you pointed to a valid MW5 .sav. Try a different save or search for broader keywords in the JSON.

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Safety and backups

This script reads your save and writes a separate JSON file. It does not modify the original save. Still, it’s good practice to back up your saves before experimentation.