Atlas Reactor contains several different systems for progressing, which give certain rewards generally for achieving milestones along them.
Seasons contain two different kinds of progression that are independent of one another and give different rewards.
Each season starts players at Season Level 1, and allows the player to increase their level by earning EXP, either by completing matches or completing certain Missions. Every level earned awards the player a Loot Matrix, and certain milestone levels also reward specific rewards, such as Banner accessories, Titles and other rewards.
Every season also has Season Chapters, which contain 5 Missions each. 4 or more of these missions need to be completed to unlock the next chapter, and each chapter completed additionally award an exclusive cosmetic item.