PRO File Format

Note: All file paths (folders) are relative to either master.dat (or critter.dat) if packed, or to Fallout's/Fallout 2's DATA folder if unpacked.

This document describes the format of Fallout and Fallout 2 .PRO (Prototype) files, which are located in PROTO/.

Each item, critter, wall, tile, and piece of scenery in the game has its own corresponding PRO file. The PRO file name is usually generated using the object's ObjectID, pre-padded by zeros so that it's 8 digits. For example, ObjectID of 32 would become 00000032.PRO.

The .PRO files in saved games (in DATA/SAVEGAME/SLOT##/PROTO/) have, like the .SAV files, been gzipped. Adding the extension '.gz' will let most archive utilities open them. Once extracted, they have the format described here.

Format description
All controlling values in an PRO file are stored in big-endian format. The first 56 bytes are common for all PROs. Those bytes are followed by values specific for each type (and subtype, for Items and Scenery).

Items
Item types:

Scenery
Types of scenery:

Repeated values
These are values that appear in more than one PRO type/subtype.

Credits for the original (pre-wiki) article
Originally written by Borg Locutus

Re-written and extended by Serge, R&D Group Leader, TeamX

Additional info by Tarantul.

Some info borrowed from FIME item editor manual by Garry

Revised by DIMS.

Translated by Dr. W95

Most content comes from the TeamX document