Lore for Shadow of War is covered on this page.
Shadow of War continues the narrative from Shadow of Mordor as the events take place between the events told in The Hobbit and The Lord of Rings. In the game you continue the story of ranger Talion who shares his body with the spirit of elf lord Celebrimbor, as they work together to use a Ring of Power to build an army to stand against Sauron and his deadly Nazgul. The story finds Talion still bound to Celebrimbor, and with a new Ring of Power. Celebrimbor believes this ring can be controlled to prevent falling into shadow, and instead use it to become a stable and powerful king. Talion agrees with Celebrimbor that it's a worthy cause to pursue and consents in the name of defeating Sauron.
The setting of Middle-Earth is familiar to many and the game will traverse iconic locations in the franchise's lore.