The wife of a man killed by a single punch amid an argument with a friend has warned the fist is "a lethal weapon".
Father-of-three Mark Munday, 48, died in hospital from a bleed on the brain after he was struck at the Grafton Hotel pub in Bedford in December 2016.
His family has backed a campaign to discourage people from resorting to violence.
Sandra Munday said: "A fist can cause as much devastation as a knife or gun.
"Take a second to think, and walk away."
"It killed my husband. It killed my children's father; three young men who still needed their dad.
"You have lethal weapons at the end of your arms. Walking away from an argument isn't weak or backing out."
Nigel Williams, 39, of Olney, Buckinghamshire, pleaded guilty to manslaughter and was jailed for five years in 2017.
The court heard he and Mr Munday, from Kempston, had been friends for 14 years and had gone on holidays together.
However, following a football match in London on 3 December, the West Ham fans fell out.
Several hours later Williams went to the pub in Midland Road and delivered the fatal blow.
Mr Munday's youngest son Matthew, 20, said: "Anyone can raise a fist and react like that. It's being able to realise that just because it's not a gun, a knife or a pole, it still causes tragedy."
Joe, 23, said: "It's about thinking before you resort to that. One punch can be devastating. That's the message we want to get out.
Their brother Sam, 25, added: "It's about reminding people that in the heat of the moment you might do something you regret and it's about taking a step back and looking at the bigger picture."
The family appears in a video being shown in schools as part of Bedfordshire Police's "One punch, two lives" campaign, which warns of the dangers of violence.
They have also raised funds for Embrace, a charity that helps to support child victims of crime, as well as Victim Support.