Based on the series four episode of the same name, the game sees Merlin fall under Morgana's spell.
Developed by Avanquest, A Servant of Two Masters will feature 15 puzzle and action mini-games, as well as a number of hidden-object adventure scenes.
Players will control characters such as Arthur, Gaius and Guinevere, as they attempt to stop Morgana using Merlin as a tool for evil.
The game's development team is said to have worked closely with Merlin creators Johnny Capps and Julian Murphy during the production of the title.
Merlin: A Servant of Two Masters will be released exclusively for the Nintendo DS on October 26, three weeks after the season five premiere on October 6.
The show's future remains uncertain after Merlin star Bradley James told Digital Spy that he wants the BBC fantasy drama to end "on a high", adding that he would only continue on the show "if everyone still has the passion for it".