Harry, third in line to the throne, spent a 20-week posting flying scores of missions over the restive southern Helmand Province in an Apache attack chopper.
The 28-year-old said Islamist insurgents were put “out of the game” and described life in Britain’s sprawling Camp Bastion base, where he slept in a tent and a shipping container.
Asked by Britain’s Press Association if he had killed from the cockpit, Harry said: “Yeah, so lots of people have.
“The squadron’s been out here. Everyone’s fired a certain amount.
“Take a life to save a life,” he shrugged. “That’s what we revolve around, I suppose.
“If there’s people trying to do bad stuff to our guys, then we’ll take them out of the game.
“As soon as we’re outside the fence, we’re in the thick of it.
“We fire when we have to… but essentially we’re more of a deterrent than anything else.”
Harry spoke to reporters on three occasions during his time in Afghanistan under an agreement which only allowed the interviews to be released once he left the war zone.
The prince supported allied troops fighting the Taliban at close quarters and accompanied British and US helicopters on missions to evacuate casualties.
As co-pilot in the Apache, Harry was in charge of the weapons systems in the two-man cockpit, firing Hellfire air-to-surface missiles, rockets and a 30-millimetre gun.
“It’s a joy for me because I’m one of those people who loves playing PlayStation and Xbox, so with my thumbs I like to think I’m probably quite useful,” he said.
When on a shift requiring a high level of readiness, Harry and the other three members of his squadron sprinted to their helicopters in less than 45 seconds and were airborne within five minutes of an alert.
They did not know their missions until they were inside their £45-million ($71-million, 54-million-euro) aircraft.