The stolen car was found burnt out in Wrack Rd, Parua Bay, on October 8.
Judge Keith de Ridder said the trio then headed to Auckland with the intention of robbing Asian people.
They booked into a motel and in the evening, drove around North Shore looking for a suitable house and came across a property on Pine Hill where two Asian people lived.
The house was broken into at around 1am. In the robbery about $190 cash, a mobile phone, a laptop, a TV, and a gold necklace were stolen after the couple was threatened with a shotgun and a screwdriver.
On October 12, the three followed an Asian man from the Sky City casino to his East Tamaki home and entered the property armed with two shotguns and a knife.
All at the home, except a woman and her two children, were tied up and four cellphones, keys, two laptops, necklaces, jewellery, about $2800 in cash, pearl earrings, rings, a bag and a pair of running shoes were stolen.
During the ordeal, a man was placed on the bathroom floor after his hands were tied and a sock put in his mouth.
He was told not to call police or else the robbers would come back and shoot him.
Crown prosecutor Catherine Anderson said the victims, particularly the occupants at the Auckland homes, were vulnerable and seriously feared for their lives.
Duff's lawyer John Watson said his client accepted his involvement in the serious offending, was deeply remorseful and extremely sorry for the distress his actions had caused the victims.
Judge de Ridder imposed a term of nine years and six months on the three aggravated robbery charges and concurrent terms of two years for kidnapping and one year for the theft of the motor vehicle.
Duff was also given a warning under the "three strikes" legislation.
