W3g extensions stand for Warcraft 3 Replay file. You can try to open w3g files with Warcraft 3 software.
Warcraft 3 is a strategy game and w3g files are used in Warcraft. There are informations about scenarios, meeting details and movements in these files. The files which are found in WarCraft 3 in installation folder can be updated when you run this game.
You can get detailed informations from its official web page of Warcraft.
What to use w3g
which page related to w3g file
w3g Related Searches
You can check related links about w3g fileextension.