MAPS.TXT File Format

MAPS.TXT contains parameters related to maps of areas in Fallout and Fallout 2. There are maps of cities, locations, and random encounters.

About
The file is a text format and is divided into tables describing locations. Each table contains a list of variables which have values of various types – text, numerical, combined. The order of variables in the list does not appear to matter.

1. Description of location tables
Each table starts with a header in the format:

[Map 001]

This line marks the beginning of the table, and also gives it a unique number (MAP ID). The highest possible number is 999, but this is unlikely to become a practical concern. Looking up the table describing a location can be done by name in the table describing locations (see below), or by the table number. MAP ID, for example, is pointed to in the same MAP file map location, in the properties of Exit Grids, in scripts, and so on.

Immediately after the header is a list of variables.

2. List of Variables

 * lookup_name - name of the location described in the table. This is the exact name indicated in WORLDMAP.TXT in the section [Encounter Table N], and is used to look up the map description in MAPS.TXT. Necessary parameter.
 * map_name - name of the map file. Just the filename of the relevant MAP (in " "). Necessary parameter.
 * music - name of the background music, excluding the ACM extension. See music_path1 in the fallout2.cfg. This is, not surprisingly, the music that will be played on this map. Necessary parameter, possibly (at least, it's always used).
 * ambient_sfx - list of names of ambient sound effect files to be played on this map (sound of the wind, gunfire in New Reno, etc.). See files in " " folder. Names are followed by a colon, then a number indicating the frequency of the effect (as a percentage), then a comma. This parameter is almost always used, but is not necessary. (Note: percentages should sum to 100; behavior if they don't is unknown.)
 * pipboy_active - has two values: 'Yes' or 'No'. Used only on the Arroyo Temple maps (has the value 'No' there). Given that you have the Pip-Boy everywhere else, this parameter is not necessary. However, this is irrelevant as the engine does not use this parameter; it just checks whether or not the 'Vault Suit Recovery' movie has been played.
 * saved - has two values: 'Yes' (for cities) or 'No' (for random encounters). Apparently, this means saving the state of the map - random encounters don't carry over to the next one. Though some random encounters have the value 'Yes'. Special encounters usually have the value 'Yes'. Necessary parameter.
 * state - a very interesting parameter. When present, it has the value 'On'. Perhaps it indicates if the player can immediately go to this map when at the city (with the 'map' of the city), even without having been there (i.e. 'opened' for him or her).
 * dead_bodies_age - has two values: 'Yes' or 'No'. Means if saved bodies are preserved or not. For random encounters it is 'No'. The default (i.e. if this parameter is not present), is 'Yes'.
 * can_rest_here - has two values: 'Yes' or 'No'. Mean if it's possible to rest on this map (comma-separated values for all three levels of the map). For random encounters it is 'No'. The default is 'Yes'.
 * random_start_point_N - the player's starting coordinates on the map (for random encounters). Up to ten can be specified (numbered 0 to 9). In general there are several points, and are chosen at random when entering the map. Each consists of two text parameters, separated by a colon. The first, elev, is the map level (from 0 to 2); the second, tile_num, is the hex number (for hex coordinates see MAP File Format). Here the coordinates are written in decimal notation; converted to hexadecimal form, the first byte will be the horizontal coordinate and the second the vertical. (Example: say we have "tile_num:24103"; in hex that's 0x5E27, so the hex is at 0x5E (94d) horizontally and 0x27 (39d) vertically.) In some random encounters the starting point is not specified, especially at special encounters. In these cases the starting point is apparently taken from the MAP file (if there is one in it).

In most cases the variables for cities, random encounters, and special encounters have some common theme, and take similar values. Therefore, when it describes a location, the first looks like the other locations of the same type.