is a character in Resident Evil (Biohazard in Japan), a survival horror video game series created by Japanese company Capcom. She was first introduced as a supporting character in Resident Evil 2 (1998), and became a playable character in Resident Evil 4 (2005). She is a mysterious and ambiguous antiheroine, working for the series' villains but also constantly bailing out Leon S. Kennedy from dire situations. Ada also appears in several Resident Evil games and novelizations. In later games, such as Resident Evil 4, The Umbrella Chronicles (2007) and The Darkside Chronicles (2009), her features were based on English actress, Sally Cahill. In the live-action films, Ada has been portrayed by actress Li Bingbing and Lily Gao. Ada has been well received from video game publications. Since her debut, she has become popular among the video game community, with high rankings among character popularity polls and considered a sex symbol. Some critics have also praised her well known red dress. Concept and design When Resident Evil 2 was still in development, Ada was a white-coat-clad researcher named Linda who aided the player throughout the game. Ada's movie model could not be finished in time. Thus she is the only main character not to appear in a pre-rendered cutscene. The character was changed for the game's final version. Story writer Noboru Sugimura was responsible for adding Ada's work in the scenario while the name Ada was conceived by Kazunori Kadoi. Speaking about the relationship between Leon and Ada, Hideki Kamiya stated in a 1998 interview following the release of Biohazard 2 that his favorite character is Ada Wong because she is "older, tougher, and has a husky voice," appealing to his preference for older women. He drew a picture of her kissing Leon. Urb said: "It's kind of like Mulder and Scully and an X-Files type of deal, where you're waiting for it to happen, but it never does. Maybe in the next one, I'm hoping." When Resident Evil 4 was ported to the PlayStation 2 after Capcom stated that it did not fall under the exclusivity deal with Nintendo, "Separate Ways", a new scenario for Ada Wong was added and written by Haruo Murata. Resident Evil 5 producer Jun Takeuchi later chose Ada and Leon's kiss scene in RE2 as his favourite element of the series. In retrospective, Kamiya feels that Ada is a manipulative character, especially if interacting with