The Crown says the fatal beating of a Featherston supermarket worker was a vigilante attack carried out in retaliation for an alleged rape.
Glen Jones' severely injured body was found in his home in January 2013 and he died some hours later in Wellington Hospital.
Matthew McKinney, Hayden Ranson, Kristopher Jones and Tariana Jones are before the High Court in Wellington accused of murder.
Another woman, Toni Miller, along with two of the murder-accused deny the aggravated burglary of Mr Jones' home. Mr McKinney and Mr Ranson pleaded guilty to that charge on Monday morning.
In his opening address, Crown prosecutor Grant Burston said the four accused of murder went to the house and attacked Mr Jones using their hands and feet, a wooden bat and a wooden axe handle, causing massive head injuries.
The court was told each of the accused had tried to minimise their own part in the incident and direct blame onto the others.
Mr Burston told jurors there were several ways in which the accused might be found guilty of murder, including if they encouraged someone else in the flat who was carrying out the attack.
Lawyers for the accused say their clients were either not guilty of any charges, or only guilty of manslaughter.
Mike Antunovic, who acts for Matthew McKinney, said his client admits going to Mr Jones' home and that is why he has admitted the aggravated burglary charge.
However, he said Mr McKinney did not believe that Mr Jones would die as a result of events that night and this made him guilty of manslaughter, not murder.
Tariana Jones' lawyer said her role was no more than that of some other young women who travelled to Mr Jones' home that night, but they have not been charged.
A jury of seven women and five men has been chosen to hear the case, expected to run for four weeks.