GAM File Format

GAM files are indexed text files. They contain global variables for each core Fallout game and its maps, and are found in  and , respectively.

Format and editing of GAM files is identical between Fallout 1 and 2.

Structure
At the beginning there is a header - "MAP_GLOBAL_VARS:" in GAM files for maps and "GAME_GLOBAL_VARS:" in VAULT13.GAM.

Next is a list of variables - first the name (as in most programming languages it can contain Latin letters, numbers, and underscores, as in "MVAR_Last_Respawn_Map"), then the assignment operator (, attributed to Pascal, Fallout's proprietary scripting lanugage), then the initial value of the variable, and at the end a semicolon.

Variables are referred to in scripts by their number in the list (starting at zero).

Variable names are always written with capitalized internal words to distinguish them from map variables, and following each variable is a comment with its number. This is done for the convenience of programmers.

Example 1
Taken from, which corresponds to the   file (Fallout 2): // Map vars for Arroyo Garden Map

// Comments

//MAP_GLOBAL_VARS: MAP_GLOBAL_VARS: //GLOBAL                                       NUMBER

MVAR_Last_Respawn_Map          :=0;            //      (0) MVAR_Current_Gecko_Easy        :=0;            //      (1) MVAR_Current_Gecko_Hard        :=0;            //      (2) MVAR_Current_Xander_Root       :=0;            //      (3) MVAR_Current_Broc_Flower       :=0;            //      (4) MVAR_Last_Spot                 :=0;            //      (5) MVAR_Kill_Runaway              :=0;            //      (6) MVAR_Dog_Already_Dead          :=0;            //      (7)

Example 2
Taken from  (Fallout 2): GAME_GLOBAL_VARS: //GLOBAL                                               NUMBER

GVAR_PLAYER_REPUTATION                 :=0;    //      (0) GVAR_CHILDKILLER_REPUTATION            :=0;    //      (1) GVAR_CHAMPION_REPUTATION               :=0;    //      (2) GVAR_BERSERKER_REPUTATION              :=0;    //      (3) GVAR_BAD_MONSTER                       :=0;    //      (4) GVAR_GOOD_MONSTER                      :=0;    //      (5) GVAR_PLAYER_MARRIED                    :=0;    //      (6) GVAR_ENEMY_ARROYO                      :=0;    //      (7)

Open with
.GAM files can be opened with any simple text-editing programs, like Notepad or WordPad.

TeamX document
Original document at teamx.ru (in Russian)