They were devised following the success of the most-wanted Iraqi playing cards (officially called "personality identification playing cards") that were used in the 2003 invasion of Iraq to help members of the U.S. military identify wanted personnel from the Baathist regime. Approximately 40,000 sets of the cards were issued to U.S. forces. In the archaeology deck, each suit has a theme: diamonds for artifacts, spades for digs, hearts for "winning hearts and minds," and clubs for heritage preservation.