The bill will reduce the maximum discount for a guilty plea from 40 per cent to 25 per cent in a move Attorney-General Vickie Chapman says will put the protection of the community first.

"The legislation also requires the courts to consider a number of factors when determining how much a sentence should be reduced to ensure the sentence reflects all the behaviour of the accused," she said.

"These include whether the defendant had concealed their crime and, if so, for how long, whether the case against the defendant was overwhelming and where the defendant has disputed the factual basis and a court has found against them."

The changes reflect recommendations from a recent review of SA's sentencing laws by former Supreme Court justice Brian Martin.

"We've also consulted with key stakeholders to strike the right balance between offering an incentive that spares victims the trauma of going to court and ensuring that justice has been done," Ms Chapman said.

Discounts on sentences for major indictable offences, such as manslaughter, causing death by dangerous driving or rape, will now range from five to 25 per cent, depending on the time of the guilty plea.

The government is also proposing to scrap a 10 per cent sentence discount for any defendant who complied with all the procedural requirements, even if they did not plead guilty.

Australian Associated Press