In 18th- and 19th-century Plains societies, most men eventually fought in battle—to protect themselves and their territory against other encroaching tribes, white settlers, or the U.S. army. But not all Indian warriors earned war shirts. Once obtained, the honor required the warrior to live up to a strict code of conduct, or the community could revoke it.
 
Plains warfare was hand-to-hand combat and followed elaborate rules of engagement. To earn a war shirt, a man needed to accomplish certain feats. In most tribes, the difficult and dangerous act of counting coup—touching the enemy during battle—was one of them.
 
A warrior could also earn a shirt by sneaking into an enemy camp to capture horses. After their introduction in the Americas by the Spanish in the 1600s, horses quickly became an essential part of the Plains lifestyle and, as symbols of wealth and prosperity, were highly valued. Consequently, two scenes often portrayed on shirts involve battles and horse raids.
 
Men drew or painted pictographs on buffalo hides and shirts to record acts of personal bravery. When worn across the shoulders, the decorated buffalo hide provided an opportunity for the warrior to recount his exploits. When the warrior-artist used this tradition on shirts, he could design the layout of his drawings to conform to the construction of the garment. Representations of defeated enemies and pipes (symbolizing the leader of a raid) were often placed on the shoulders, whereas specific battle deeds were illustrated on the lower portion of the shirt.

"We were in the Second World War. And back [in] that day, our top [GI] garment was a blouse, you probably knew about that. And then came the Eisenhower jacket. Little short, beautiful piece of garment, far as that goes. Then, we had the ribbons. Some have ribbons all the way down...Campaign ribbons...they’re really special. They’re very sacred. And the...war shirt is a very special garment to the individual that owns it. They don’t wear it every day. Only on special occasions. Special ceremonies....And before an individual becomes an outstanding chief, he’s got to accomplish so many [kinds of] particular requirements." -John Hill (Apsaalooke)

Upper Missouri Region Shirt (front), about 1858	Dakota Shirt (front), about 1880