For the first two seasons, Riker is portrayed as a bold, confident and sometimes arrogant, ambitious young officer; however, over time Riker’s character becomes more reserved, as experience teaches him the wisdom of a patient, careful approach. He becomes comfortable on the Enterprise, repeatedly turning down offers of his own command, and he learns to cherish the company of his fellow officers. Nonetheless, Riker retains a willingness to occasionally disregard the chain of command. Riker is usually referred to as “Will”. He is also usually (and informally) called “Number One” by Captain Picard, because of his position as first officer on the Enterprise.
Riker’s background is first explored in the second-season episode “The Icarus Factor“. In the episode, Riker’s estranged father, Kyle, visits the Enterprise to offer his son the command of the USS Aries, which Riker refuses. We learn that: Riker grew up in Alaska; that his mother, Elizabeth (Betty), died when he was two years old; and that he was raised by his father until the age of 15, when he left home. In the episode, Riker had not spoken with his father for 15 years, but they manage to partially mend their relationship over a game of martial-arts sparring called Anbo-jitsu. In the episode “Lower Decks” a waiter at Ten Forward mistakenly states that Riker is Canadian, and in the same episode Riker clarifies that he grew up in Alaska. According to the Voyager episode “Death Wish” (in which Riker made a guest appearance), Riker’s distant ancestors also lived in the United States: during the American Civil War, his ancestor Colonel Thaddeus Riker fought on the Union side, as an officer in the 102nd New York Infantry Regiment during the Atlanta Campaign.
In the two-part episode “The Best of Both Worlds” Riker takes command of the Enterprise, assuming the rank of captain through a field promotion, and orchestrates Picard’s rescue. This episode also explores the idea of Riker being unwilling to take chances since he had grown comfortable in his role as First Officer aboard the Enterprise. By the end of the episode, when he orders the Enterprise to fire on former Captain Picard, now Locutus of Borg, Riker has grown into a more confident leader. The sixth-season episode “Second Chances” reveals that Will Riker was duplicated long ago by a transporter malfunction. The “second” Riker takes the name “Thomas“, which is revealed to be William Riker’s middle name. In the seventh-season episode “The Pegasus“, Riker must confront his former commanding officer, Admiral Erik Pressman, over a cover-up related to the destruction of the USS Pegasus. The Pegasushad illegally developed a radically different type of cloaking device that also allowed it to phase through matter, resulting in it becoming fused within an asteroid when unstable power consumption forced the cloaking device offline. In the Enterprise series finale, Riker appears as a never before seen cook discussing matters of life, duty, and sacrifice with the crew. It is revealed that his presence is part of a holodeck simulation of historic events that Riker initiated in order to help himself make the decision to inform Captain Picard of the illegal research once conducted by Admiral Pressman aboard the Pegasus.