Fourteen people, 12 to make up the jury and two additional jurors who will sit through the opening, were selected from a panel of 30 at Preston Crown Court yesterday.
Judge Sir Peter Openshaw told the five men and nine women it was their duty to decide the case based on evidence heard in court.
He said: “As all of you will probably know, there has been a huge amount of publicity about the Hillsborough stadium disaster.
“What any of you have heard or read or seen in the past, and what any of you may hear, read or see in the future, is entirely irrelevant to your task, which is to decide whether or not the charge, as laid by the prosecution against this defendant, has been proved and proved by the evidence that you hear and see in this court.”
He said the same applied to decisions made by other inquiries, inquests and trials.
“You will hear that there have been previous trials against this defendant in which the jury has disagreed,” he said.
“That other juries have failed to agree on a verdict is also quite irrelevant to your decision.”
He warned the jury not to research the case on the internet or post about it on social media.
He said: “I’m sure if you Google the Hillsborough disaster there will be many millions of entries.
“Don’t do it.”
The names of 95 victims of the disaster, which happened at the 1989 FA Cup semi-final, were read out in court as part of the indictment.
Duckenfield, 75, who denies manslaughter by gross negligence, sat in the well of the court wearing a suit and blue tie.
His wife, Ann, was in the public gallery of the courtroom, as were about eight relatives of victims.
On Monday, 100 potential jurors were given a questionnaire which asked for details including whether they supported Liverpool or Everton football clubs and if they or any close relatives had ever worked for the police.
They were told the case could last six to seven weeks.
Ninety-six men, women and children died in the crush in pens at the Leppings Lane end of the Sheffield Wednesday ground at the match between Liverpool and Nottingham Forest on April 15 1989.
Under the law at the time, there can be no prosecution over the death of the 96th victim, Tony Bland, as he died more than a year and a day after his injuries were caused.