In "The Witcher 3: Wild Hunt," several choices have a significant impact on the world, the characters, and the various endings you can experience. Here's a breakdown of the most consequential decisions: **Main Quest Decisions:** 1. **The Fate of the Bloody Baron and his Family:** Depending on what you do in the quests "The Whispering Hillock" and "Family Matters," you can affect whether the Baron lives or dies, as well as the fate of his wife and daughter. This will impact the state of Velen. 2. **Ciri's Fate:** Major choices that influence Ciri's future include whether or not you take her to visit Emhyr, your responses to her in key moments (showing support and treating her as an independent adult are usually the positives), the outcome of the Battle of Kaer Morhen, and whether you allow her to face the White Frost. 3. **The Battle of Kaer Morhen:** The characters who survive and how they view Geralt can be influenced by the decisions made leading up to and during the battle, especially through the various subquests that involve recruiting allies. 4. **The Rulers of the Northern Realms:** Decisions made in the quests involving Radovid and Dijkstra can drastically change who rules over the Northern Realms at the end of the game. 5. **Romance Choices:** Deciding between Yennefer and Triss (or trying to romance both) will have a significant impact on Geralt's personal life and the game's ending. **Side Quest Decisions:** 1. **The Fate of Keira Metz:** During the "For the Advancement of Learning" quest, your choices will decide Keira’s fate, potentially leading her to a helpful role in the Battle of Kaer Morhen or to her death. 2. **Saving the Mages of Novigrad:** During the "Now or Never" quest, helping Triss save the mages can affect the politics of Novigrad and the fates of non-human characters within the city. 3. **The Carnal Sins Quest:** Your investigative decisions can lead to catching the right or wrong suspect. The outcome changes the futures of the characters involved and the mood in Novigrad. 4. **The Isle of Mists and Brothers in Arms Quests:** Who you recruit and how you've interacted with potential allies will influence the Battle of Kaer Morhen’s outcome. 5. **The Possession and The Cave of Dreams Quests:** Your choices on the Skellige Isles can significantly alter the leadership and future of the Skellige clans. 6. **The Ghosts of the Past:** If Letho is alive (depending on choices made in "The Witcher 2" or the simulated save), his questline can impact his involvement in the rest of the game. Keep in mind that even smaller decisions in dialogues, contracts, and secondary quests can have more subtle effects on the world and your relationships with other characters. For the most part, "The Witcher 3" rewards you for thoughtful consideration and exploring the consequences of your actions in its rich and dynamic world.