Specific sets of rules govern what form a heraldic design may take. They may consist of a simple pattern of colors, but more often feature animals (either real or mythological) and/or physical objects.
These heraldic devices are also carried by armies on the battlefield as a sign of status, as well as allegiance to those noble Houses. The various noble Houses of the Seven Kingdoms use distinctive heraldry to identify families and individuals. It's a great honor to carry your House sigil.' - Jon Snow explains to Ygritte the wildling the importance of heraldry in the Seven Kingdoms.
Ygritte: ' Is that how you lot do your fighting? You march down the road banging drums and waving banners?' Jon Snow: ' Most of the time, yes.' Ygritte: ' How do the men holding the banners fight?' Jon Snow: ' They don't, really.
