Blackjack Idols is a twist to Hidden Immunity Idols that featured in Survivor: Kiribati. It required the players to beat the host at a game of blackjack to receive a clue to an idol. However if they were lucky enough, players could win an idol outright. The twist returned for Survivor: Canary Islands when it was picked as part of the Make Your Mark twist, and played out one more time in Survivor: Ragnarok.
In order to receive a hidden immunity idol clue, castaways from the winning tribe(s) had to compete against the host in a simple game of blackjack. Win the hand and you get a clue. However, if a castaway was lucky enough to get 21 on the dot, they would have won themselves a whole idol outright, to be used as standard. If a player went bust or did not beat the host, they would leave without an idol or a clue. Their fate was put into the luck of the draw.