- "I know this for a fact because she'd never destroy a beautiful mad probability droid."
- ―Chelli Aphra, to the gundravian hookspores
A probability droid was a droid that was fitted with probability tech. The modified droideka Dek-Nil was a probability droid whose existential circuits had also been altered. As a probability droid, Dek-Nil could quickly calculate the chance of events occurring, as well as predict events before they happened.
- Doctor Aphra 15: Remastered, Part II (First appearance)
- Doctor Aphra 16: Remastered, Part III
- Doctor Aphra 17: Remastered, Part IV
- Doctor Aphra 18: Remastered, Part V (First identified as Probability droid)
- Doctor Aphra 19: Remastered, Part VI
- Doctor Aphra 20: The Catastrophe Con, Part I
- Doctor Aphra 21: The Catastrophe Con, Part II
- Doctor Aphra 22: The Catastrophe Con, Part III
- Doctor Aphra 23: The Catastrophe Con, Part IV (Head only)
- Doctor Aphra 24: The Catastrophe Con, Part V (Head only)
- Doctor Aphra 25: The Catastrophe Con, Part VI (Head only)