All child witnesses will now pre-record their evidence instead of going to court as new legislation comes into force.
The change is aimed at helping children under the age of 18 who have witnessed some of the most serious crimes and means they can no longer be asked to testify in the High Court.
Justice secretary Humza Yousaf hailed the measure as a “significant milestone”.
Mr Yousaf, together with senior judge Lady Dorrain, the Lord Justice Clerk, has already opened a specialist facility in Glasgow where children can have their evidence recorded.
Similar centres are planned in Edinburgh, Aberdeen and Inverness.
The provision was part of the Vulnerable Witnesses (Criminal Evidence) (Scotland) Act, which was passed by Parliament in 2018 and has been backed with £3m of funding.
Speaking as the change came into force, Mr Yousaf said: “Today marks a significant milestone in Scotland’s journey to protect children as they interact with the justice system and a key part of our wider work to strengthen support for victims and witnesses.
“Children who have witnessed the most traumatic crimes must be able to start on the path to recovery at the earliest possible stage and these changes will allow that, improving the experiences of the most vulnerable child witnesses as far fewer will have to give evidence in front of a jury.”
The change will apply to children giving evidence in cases such as murder, culpable homicide, domestic abuse, sexual offences and assault to the danger of life.
Mary Glasgow, chief executive of the charity Children 1st, said: “Children have told us that they found giving evidence in court almost as traumatic as the abuse itself.
“This act means more children will now be able to give pre-recorded evidence in an environment more suitable to their needs.
“It also reduces the time children wait to give evidence and means they will not have to face the accused.”
Holyrood’s Justice Committee has been pushing for ministers to adopt the Scandinavian Barnahus – or children’s house – principles in Scots law.
Under such a setup, youngsters could be interviewed, medically examined for forensic services and receive therapy in a single centre.
Justice Committee convener Margaret Mitchell said the changes being introduced were an “important first step towards realising the committee’s vision of a Scottish version of the Barnahus model”.
“We recognise the potential stress caused by giving evidence and we want to ensure steps are taken to avoid children being retraumatised by the court processes,” she said.
Ms Mitchell and other members of the committee visited a centre in Oslo that provides youngsters with wrap-around support.
She said: “On our visit to Oslo, we were struck by how the Barnahus provided wraparound support.
“Members therefore welcome the Scottish Government’s ongoing work to introduce a similar approach for child victims and witnesses in Scotland.
“Today is a milestone in the move towards a new way to support victims and witnesses giving evidence.”