"Complicated" is a song by Barbadian recording artist Rihanna from her fifth studio album Loud (2010). It was written and produced by Tricky Stewart and Ester Dean. "Complicated" is a dance-pop, hip hop and trance music song, which also displays elements of pop, dance-pop and R&B. It contains lyrical content explaining how two people in a relationship can find one another complicated at times. The song was acclaimed by critics, as the majority of reviewers concluded that it was one of the best tracks to be included on Loud. Reviewers also praised Rihanna's vocal performance in the song. Upon the release of the album in November 2010, the song charted at number 50 on the South Korea Gaon International Chart.