Dr. Radek Zelenka is a careful and precise scientist of the original Atlantis Expedition who often supplements the scientific decisions of the "equally brainy" Dr. Rodney McKay, with whom he has a friendly rivalry. He frequently appears in the control room with McKay and the leader of the Atlantis expedition for expository scenes to lay out an episode's premise to the audience, and is "a key player in helping the Atlantis team stay one step ahead of the bad guys as well as solving some of its most perplexing scientific conundrums". GateWorld's David Read felt that while Zelenka may "play second fiddle to Rodney", he is also "the only one who even has the potential to put McKay down." Actor David Nykl explained that Zelenka has "reasonably well honed social skills" and "can put up with a lot of stress [...] and a lot of pressure, particularly from McKay and the situations that he can get into", but he may be too focused and determined to get one thing done.