Judges must impose longer jail terms on people who kill in street fights or cases where "one punch" causes death, says the Lord Chief Justice.
Lord Judge told the Court of Appeal the public expected better protection from alcohol-related violence.
The new guidance came after appeals by the attorney general for tougher sentences for sudden street attacks.
In one case, a man is being returned to prison despite having earlier been freed on licence.
The new guidelines set out by the Lord Chief Justice relate to cases of extreme and sudden street violence generally known as "one-punch manslaughters", where a defendant causes the death - but is usually not found guilty of murder.
But Lord Judge told the Court of Appeal that the phrase was misleading.
"The cases with which we are concerned involved gratuitous, unprovoked violence in the streets of the kind which seriously discourages law-abiding citizens from walking their streets, particularly at night," he said.
"[It] gives the city and town centres over to the kind of drunken yobbery with which we have become familiar, and a worried perception among decent citizens that it is not safe to walk the streets at night."
Lord Judge, sitting with four senior colleagues, said Crown Court judges must respect juries who conclude that an the attacker did not intend to kill - but said jail sentences had to reflect public disquiet.
In the case of Declan Appleby of Redcar, the judges agreed with the attorney general that his sentence should have been longer - and ordered him to serve nine rather than six years.
The 19-year-old killed 52-year-old grandfather Ron Sharples in the early hours of New Year's Day 2008. Mr Sharples had intervened to stop a fight but was hit by Appleby and one of his friends.
In the second case, Thomas Bryan and Peter Roberts were jailed for a "retaliatory" attack on a man, following some form of confrontation in a Rhyl nightclub.
Bryan, 46, had his three-year sentence increased to five years. Roberts, 37, was told his 18-month term would be doubled to three-and-a-half years. He was ordered back to jail, having earlier been released on licence.
The judges dismissed a separate appeal against sentence by two brothers, Ben and Tom Cowles, who had killed a 45-year-old father-of-two in a similar act of street violence in Norwich.
The Lord Chief Justice said there were genuine examples of one-punch manslaughters which still needed to be sentenced differently.
These included cases where an attacker had acted irrationally and had then been so shocked by their own actions that they had tried to save the victim's life.
By coincidence, 46-year-old Paul Harvey was jailed for three years at the Old Bailey on Friday for the "fluke" manslaughter of his wife, Gloria Laguna.
He threw a TV remote control at her during a row. It struck a weak artery on her neck and led to a brain haemorrhage. Harvey tried to resuscitate her as she died.