Map file

Map files, .map files or map cache files, are a file type employed within the Blam engine used by all first-person shooter Halo games. As their name suggests, they are the files which store data for campaign levels and maps for multiplayer, Firefight and Spartan Ops. Due to the uncertainty of game development, map names change frequently during production and may not be finalised until relatively close to release. As such, a map's display name in the in-game user interface is often completely different to the actual .map filename inside the game directory. This information is primarily used in modding.

This page intends to serve as a general overview of the .map file type; for in-depth technical information, see this page on the c20 Reclaimers Halo modding wiki.

Overview
Within the Blam engine, tags serve as containers which store data about a given subject. These can range from characters, weapons, and vehicles to projectiles, props or whole maps. Map files serve as tag collections, containing all of the data needed to load and run a given map or level.

Within the map structure, the primary component that dictates the actual level itself is the scenario tag. Scenario tags contain information about the actual level data such as player and enemy spawns, weapons and vehicles, objectives, and so forth. Scenario tags share the same name as the map file, and are compiled using the Tool component of the Halo Editing Kit alongside the various tags loaded by the scenario tag to form the map file.

Halo 3
Released Halo 3 .map files can be found in the,  , and   folders.

Halo 3: ODST
All Halo 3: ODST campaign .map files are in the  folder.

Halo: Reach
All Halo: Reach .map files are in the  folder.

Halo 5: Guardians
Halo 5: Guardians never saw a full PC release and as such, the full index of map names for the game is unknown. A limited component of the game was released on Windows Store as Halo 5: Forge, allowing most of the game's multiplayer maps to have known names.