Making your opponents doubt the strength of your hand is the fundamental component of bluffing. You can give opponents the impression that you are following a different strategy than you are by discarding some cards or keeping othrummy kingdomers longer than is necessary. This psychological component gives the game more depth and may present opportunities for you to take advantage of their errors in judgment. But bluffing effectively necessitates careful observation & knowledge of your opponents' patterns. By making daring moves that give the impression that you are about to win when you are not, you can take advantage of a player who you know is cautious or easily alarmed by perceived threats.