After the ark Hyperion arrives at the Andromeda galaxy, Alec Ryder leads the Pathfinder team to scout Habitat 7 for colonization. Electrical storms stranded the team and they have hostile encounters with an alien species called the kett. Eventually, Alec surmised that the kett are alien to the planet as well and were studying a Remnant structure. SAM elaborates that the Remnant tower is creating a dark energy cloud that is disrupting the world's climate with undirected energy. Alec believes turning off the Remnant structure will clear the weather and make it feasible for the Hyperion to extract the Pathfinder team.
Alec and the younger Ryder eventually make it to the Remnant structure's control console and Alec uses SAM to help him interface with the structure. Alec succeeds in shutting down the Remnant structure and stabilizing the world's atmosphere, but activation of the processor also causes its purification field to throw both Ryders off the platform. The younger Ryder's helmet is hit by a stray container, damaging it beyond repair. Alec requests immediate evacuation but realizing that they wouldn't be rescued in time, decides to sacrifice himself and give up his helmet to save his progeny. Before Alec suffocates, he passes down the mantle of human Pathfinder to his rescued progeny by transferring SAM's command access onto them.
Pathfinder Ryder commands the Tempest in their father's absence and leads the search for humanity's new home in the Heleus Cluster. As the only known Pathfinder to report to the Nexus, Pathfinder Ryder is tasked by the Nexus leadership to ensure the Andromeda Initiative's success. Pathfinder Ryder's goals are many: to make the planets of the Heleus Cluster hospitable for colonization, to find the missing arks, and to defend the Initiative from the hostile kett. To aid with their mission, Pathfinder Ryder is synced with an advanced Artificial Intelligence called SAM.
Ryder can be of either gender. The name, appearance, and background can be customized. The non-selected twin is reawakened out of cryosleep later, is always named Scott or Sara, and will also have a significant presence as the story unfolds. Ryder's mother is Ellen Ryder, and her devastating illness was a tragic blow to the family. Ellen suffered from AEND, a rare terminal neuro-degenerative disorder with no known cure.
- Main article: Training
One of six different training backgrounds can be chosen. These determine Ryder's initial skill point distribution at the start of the game but have no story consequences.
- If the player keeps the Pathfinder's default first name then they will occasionally be referred to as that in conversations rather than just by their title and last name.
- When speaking to Jaal Ama Darav about biology and vestigial organs, the Pathfinder will remark that Scott has several webbed toes, while Sara had wisdom teeth.