Why was Jadzia Dax written out of Star Trek: Deep Space Nine so late?
At the end of season 6 of Star Trek: Deep Space Nine:
Jadzia Dax is killed.
At the start of season 7:
A “new” character, Ezri Dax, the next host of the Dax symbiont, is introduced.
This results in quite a few episodes in the first half of season 7 featuring Ezri heavily (including three full “Ezri episodes” — Afterimage, Prodigal Daughter, and the god-awful Field of Fire). I assumed this was an intentional attempt to get the audience to care about the character before the big finale of the show kicks into gear.
But it does seem like a lot of effort to go through at this stage in the show. Bringing in a whole new character just for the last season seems like an odd choice. Although it was really interesting to explore the same-symbiont, different-host thing, and Nicole De Boer did a great job with the character, were there behind-the-scenes reasons for Jadzia being written out?
And in a couple of weeks time I’ll do a “Why wasn’t anyone written out of Deep Space Nine right in the middle of season 4?” question to round out the trilogy.
According to Memory Alpha, Dax's actress Terry Farrell decided to not renew her contract for season 7 in order to go to some sitcom called Becker (bunch of rumours why). So the DS9 crew were forced to kill Jadzia off.
According to Farrell, they were upset at her decision to leave and implied that they killed off Jadzia out of spite.
@PaulD.Waite "I'm sure at that point, too, for Rick Berman and those people, it was all or nothing. They were angry because I wasn't doing what they wanted me to do or expected me to do. So it was an unfortunate situation all the way around." http://www.startrek.com/article/the-trill-of-it-all-undefinedterry-farrell-interview-part-2