Trial by Fire

 is a recurring double-elimination twist in Castaway.

Similar to the fire-making challenge, the eliminated player (in a round where a Trial is known or at times announced at Tribal Council) nominates two players from their former tribe to compete to stay in the game with the losing player exiting the game permanently.

Overview
Debuting in Castaway: One World (though have been one-time advantages in Castaway: Philippines and Castaway: Kaôh Rōng) its purpose was to permit the eliminated player the opportunity to pit members of a particular alliance against one another. The presence of a Trial by Fire becomes known at the start of an Immunity Challenge where Robert informs the tribe(s) that two players will be eliminated. Whilst double eliminations have been used in previous seasons to moderate success, the intention of the twist is for players to be more transparent and have more opportunity to play advantages.

When a player is voted out, that individual can select any member of their former tribe to compete in a duel. Any immunity or advantages played during the Tribal Council become void and no player can exercise an advantage during this period. The duel takes place immediately following Tribal Council in observation of the visiting tribe with the winner retaining their position whilst the loser exits permanently alongside who was voted out.

Following One World, Tribal Councils with Trial by Fire were attended solely by the voting tribe. A rule change in Castaway: Micronesia permitted castaways to play a hidden immunity idol before the voted out player could nominate. Starting in Castaway: San Juan del Sur castaways could be voted into a Trial by Fire.