Her Valdemar novels include interaction between human and non-human protagonists with many different cultures and social mores.

Her other main world is similar to Earth, but it includes clandestine populations of elves, mages, vampires, and other mythical beings.

[4] She placed her meeting with science fiction at age 10 or 11, when she picked up her father's copy of James H. Schmitz's Agent of Vega.

Lackey had difficulties obtaining enough interesting books from the public library to sate her passion for reading.

[5] While at Purdue, she took a one-on-one class of English Literature Independent Studies with a professor who was a fellow science fiction fan.

During this time, Marion Zimmer Bradley included Lackey's short stories in an anthology, Friends of Darkover.

[6] Despite getting her own start as a fanfiction author, she and her agent forbade fan fiction based on her own books for many years, whether distributed offline or online.

Other mentors include writers C. J. Cherryh and Andre Norton, along with her editor, Elizabeth (Betsy) Wollheim of DAW Books.

Her earlier Velgarth novels are all solo projects, but later volumes in the Valdemar saga are illustrated by her husband Larry Dixon, and in many of her latest works he is also credited as co-author.

She has worked with fantasy authors Andre Norton (such as the Halfblood Chronicles), Marion Zimmer Bradley (such as Rediscovery and Tigers Burning Bright), Anne McCaffrey (such as The Ship Who Searched), and Piers Anthony (If I Pay Thee Not in Gold).

[6] On August 3, 2021, Deadline reported that Radar Pictures had acquired the television rights to the Valdemar novels and that Ted Field would be Executive Producer on the series.