Survival Duels, known as Disclosure Duels in the Japanese version (or Des Duels, a pun on Death Duels, for short in Japan pronunciation) are mandatory Duels issued by Thelonious Viper at Duel Academy.
Bio-Bands were used to drain both the victor and loser's energies upon the conclusion of the Duel. It is the skill system for open duels regardless of dorms or grades.
In other mediums, usually video games, Survival Duels instead form a different game mode designed to test the player's endurance, where the player has to defeat several (sometimes random) opponents in a row, with their Life Points carried over between Duels. Most of the time, if the player's Life Points exceed 10,000 at the end of a duel, it is set to that amount at the start of the next Duel. The rules of the WRGP take up a slightly modified version of this game mode, with the winning player's entire field setup (including hand, Graveyard, Banished Zone and unshuffled Deck) carrying over after a victory.