The Reason of State quest stands as one of the most politically consequential side missions in The Witcher 3: Wild Hunt. Occurring in Act III, this quest forces Geralt of Rivia to take a direct hand in deciding the fate of the Northern Realms. Navigating its prerequisites, ambush mechanics, and final moral crossroads requires a clear understanding of the quest's underlying structure.

Prerequisites and Unlocking the Mission

To access Reason of State, players must first complete a chain of side quests in Novigrad, including A Deadly Plot, An Eye for an Eye, and Redania's Most Wanted. Additionally, Geralt must share critical information about Emperor Emhyr with Sigismund Dijkstra during the main quest Blindingly Obvious rather than using physical force. Missing any of these steps permanently locks out the questline, allowing King Radovid V to remain in power.

Executing the Assassination Plot

The quest begins in a Novigrad portside warehouse where Geralt meets with Vernon Roche, Thaler, and Dijkstra to finalize the plan. Geralt agrees to lure King Radovid into an ambush by pretending to have found Philippa Eilhart. Once Radovid arrives on the bridge near Temple Isle, the trap is sprung, resulting in an intense skirmish where Geralt must help eliminate the king's royal guard.

The Final Crossroads: Dijkstra vs. Temeria

After King Radovid is slain, the conspirators gather in Irina's theater to discuss the aftermath. Dijkstra unexpectedly betrays Vernon Roche, Ves, and Thaler, planning to eliminate them and unite the North under his own rule. Players face a critical decision to either walk away, leaving the Temerian patriots to die, or stand and defend Roche by killing Dijkstra.

Political Impact on the Epilogue

Choosing to defend Roche results in Nilfgaard winning the Northern War and restoring Temeria as a vassal state. Conversely, siding with Dijkstra allows him to defeat Nilfgaard and establish a unified, strictly governed Northern Empire. Additionally, the outcome of this quest directly influences whether Ciri can potentially become the Empress of Nilfgaard in the final epilogue.