Conditions for obtaining all endings (The Witcher 3: Wild Hunt)

Best Ending

Geralt acts as a good "father" and mentor to Ciri, who knows how to approach her. Overwhelmed with positive emotions, Ciri returns from the White Frost. Geralt goes to Emhyr, who is informed that Ciri is dead and will not return. After that, Geralt goes to the Nilfgaardian camp, which is located in the White Gardens, and there he receives a wonderful silver sword from the master. Next, Geralt meets with Ciri in a tavern, where he gives her this blade, then they go together to the highway. In this ending, Ciri becomes a witcher, which is essentially canonical, if you correctly understand her character. She wanted freedom and to do what she wanted. After Geralt taught her all the skills, Ciri sets off on a free voyage, and the news of the great ash-haired witch will spread from the shores of the Yaruga to the mountains of Kovir.
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Good ending

Geralt acts as a good "father" for Ciri, who knows the approach to her. After the portal to the White Frost, Ciri returns and goes to Nilfgaard, where Emhyr will prepare Ciri to become an empress.
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Bad ending

In this case, Geralt acts as a not very good mentor and "father", who cannot support Ciri in difficult times and does not understand her character, sometimes even disgracing himself in her eyes. After Ciri goes through the portal to meet the White Frost and she replays all these memories in her head, she doesn't come back. In fact, it is believed that she dies in this ending. Events take Geralt to the swamps, where he goes in search of the third Witch and finds her. After defeating the witch, he finds a box in the house, in which Vesemir's medallion lies, and remains there alone with himself in grief and despair.
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Additional endings

In addition, there are 3 variants of this ending, which depend on the state of affairs in the war
Ending #3A

Geralt supports Vernon and Thaler after killing Radovid, which will lead to "Nifgaardian terms". Temeria will become a vassal state, allowing its own economy and development. Emhyr will capture the entire North and destroy the opposition in his circles
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Ending #3B

Geralt supports Dijkstra and kills Radovid, which will lead to the "Dijkstra Rule".[23]
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Ending #3C

This ending will appear if Geralt does not fulfill the conditions above. Radovid will remain alive, he will be able to unite the North and repulse Nilfgaard. After a series of defeats, Emperor Emhyr will be killed by people from the opposition.