Survivor (American TV series)
During Guatemala, the hidden immunity idol was not returned to the game after its use.  Since then, if the idol is played, or the player with the idol leaves the game without playing it, the idol is replaced at a new spot to be found, and new clues are given out. During Gabon, the players all decided to throw a hidden immunity idol into the sea. In this case it was not replaced at a new spot. In some seasons, fake hidden immunity idols have been made by contestants; these idols don't work if played.