Map Editor

A map editor is a tool created by the game developer to allow players to create their own levels and maps. Map editors are also used by the game developer to easily assemble new campaign levels and multiplayer games. Game Maker's built-in "map editor", the Room editor, is designed for work on simple 2D games; but is still extremely handy.

Tools
Map editors, ranging in genre and ability, mostly have similar tools.
 * Terrain sculpting
 * Terrain painting
 * Object/building placement
 * Vegetation spread
 * Digging out water bodies
 * Road layout
 * Wall/floor/stair/ramp layout
 * Node placement for goal points, AI actions/movement, and particle emitters
 * Light placement and lighting options
 * Materials browser
 * Tile placement for decorating 2D worlds