Death cards or calling cards were used in the Vietnam War by US as a form of psychological warfare. They would place the cards with their unit written on them, on dead enemy soldiers they had killed.
Placing a card in the mouth or on the body as a way of striking fear into the NVA and Vietcong who came across their dead comrades. The most recognized and commonly used card in the deck was the ace of spades.
The ace of spades was a symbol of good luck for the 101st Airborne in World War two because of its good fortune in card games, but in the Vietnam War it became a symbol of death and fear. This particular card was chosen after a legend started to spread among the American soldiers that the North Vietnamese were superstitious of the ace of spades as a symbol of death and ill fortune. Even though this was completely false.
The popularity of the symbol nevertheless grew rapidly among American troops.
In February 1966 two lieutenant's of Charlie Company 2nd Battalion 35th Infantry Regiment asked the US playing card company to send them 1,000 card decks with just the Bicycle Ace of Spades in them. The company said yes and sent them free of charge, with the crates marked bicycle secret weapon.
The media even started to report how bombers could clear an entire area of North Vietnamese soldiers faster by merely dropping playing cards with the ace of spades instead of bombs regardless of it actually having any effect on the enemy.
The legend of the ace of spades became a morale booster for the American troops they put them in their helmets and place them on the enemy they had killed.
Implying the ace of spades was the last thing they saw.
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