Files with the extension .SGA are created and used by games developed by 'Relic Entertainment'. .SGA archives are compressed files often containing maps or large groups of related files used by Relic games. Compressed files (zipped) i.e. files reduced in size by use of an 'archiver' application offer reduced storage needs and faster transfer via the internet, etc. Popular Relic games utilising the .SGA format include: DOW (Dawn of war). Company of heroes. * See links for examples of .SGA unpacker / explorer tools.