The DLG file stores dialogue resource script for Windows. It cannot be converted to other formats. A dlg file contains dialog resource scripts which the Windows system uses. It seems to be a format exclusive to that software.
DLG Tools & Apps also exist for viewing, editing, converting, merging, splitting, and comparing DLG files. These are free online apps that don’t require installing. This allows working with DLG files easily.
A DLG file is also used by games like Crysis. It contains character dialogues referenced during gameplay by Crysis, developed by Crytek. Users can edit this with a text editor. Enigmap.com lists softwares that can open DLG files. The original DLG-3 standard is for mapping images. It is now being migrated to a newer standard called DLG-F.
Visual C++ also uses the DLG extension for dialog templates. These files contain the common dialog templates. The Bioware Aurora game engine uses DLG for dialog data between characters. Games will reference the appropriate DLG file for dialogues. If there are issues opening DLG files, update the software to the latest version which supports the newer format.
We try to provide guidance on software that is compatible for editing, converting or printing DLG files. This assists users in handling these file types smoothly. There are multiple different uses of the .DLG extension by various softwares, for different data types.
ArcGIS
QGIS
Global Mapper