Map

From The StarCraft 2 Wiki

A Map is a user-created file that is readable for use within the Warcraft III engine. A map is made up of mostly Terrain which is the base of the map, Triggers which give the map functions and/or actions, Units which add life to the map and spells which give the user the ability to attack foes in a variety of ways other than just hack and slash.

Maps can come in two forms: The first form is .w3m, which is a map file that has been created using Warcraft III Reign of Chaos, although a .w3m map can be made in Warcraft III The Frozen Throne by using Reign of Chaos specific requirements (more on that later), it is easier if the user created the map originally with Reign of Chaos only installed. .W3m maps are playable in both Warcraft III Reign of Chaos and Warcraft III The Frozen Throne through the Custom Game/Single Player Campaign modes.

The second form is .w3x, which is a map file that has been created in either Warcraft III Reign of Chaos, or Warcraft III The Frozen Throne. The requirements for making a .w3x map is as simple as creating a map with 256x256 dimensions, adding a single The Frozen Throne unit (i.e. Destroyer), modifying Triggers in certain ways (i.e. using The Frozen Throne only triggers/variables), editing a unit to use The Frozen Throne abilities or using Doodads and Destructibles that are only in The Frozen Throne. More on what makes a map a .w3x only later.

Mapmaking Navigation [e]
Basics:	Terrain | Triggers | Cameras | Variables | Object Editor | Mods | Campaign Editor | StarCraft II Map Editor | WarCraft III World Editor | Tilesets | Use Map Settings | Locations | Map | Doodad | StarCraftWire Map Database
Advanced:	Hyper Triggers