Cardinal George Pell could be released from custody next week if his appeal against his child sex abuse convictions is successful.

Key points: If the jury's verdict is judged to be unreasonable, Pell's conviction will be overturned

If the jury's verdict is judged to be unreasonable, Pell's conviction will be overturned If the judges find the court erred, a retrial could be ordered

If the judges find the court erred, a retrial could be ordered The appeal outcome could itself be subject to a High Court appeal

The Victorian Court of Appeal will rule on whether to overturn Pell's convictions for sexually abusing two choirboys when he was archbishop of Melbourne in the 1990s.

It was announced that judgment will be handed down on Wednesday, August 21.

A jury found Pell guilty last December of sexual penetration of a child under 16 and four counts of committing an indecent act with a child, making him the highest ranked Catholic cleric ever convicted of child sex abuse.

Three judges have scrutinised the case and will take their seats behind the bench to announce their decision from 9:30am on Wednesday.

The proceedings will be live streamed on the Supreme Court of Victoria's website.

So what are the possible outcomes?

Chief Justice Anne Ferguson, Justice Chris Maxwell and Justice Mark Weinberg are deciding the appeal outcome. ( Supplied: Supreme Court of Victoria )

If the court finds the jury got it wrong:

Pell's central ground of appeal was that the guilty verdicts were unreasonable because there was insufficient evidence for a jury to have been satisfied of his guilt beyond reasonable doubt.

It's a high bar.

The judges would need to be convinced that any properly prepared jury must have entertained a reasonable doubt, not that they merely could have.

Pell's barrister, Bret Walker SC, told a previous hearing that the jury could not have excluded a reasonable doubt because of the many improbabilities contained in the victim's evidence.

If the judges agree, Pell's convictions will be quashed.

The cardinal will then be released from custody immediately. He could be free to walk out the Victorian Supreme Court's front doors.

But his freedom could be short-lived as Victorian prosecutors could appeal against the decision in the High Court.

Pell was found guilty at the end of a second trial after the first jury to hear his case couldn't reach a verdict. ( Supplied: Fay Plamka )

If the court rules errors were made during Pell's trial:

Pell's other two grounds for appeal were described by his barrister as "fall-back" options for if the judges disagreed the verdicts were unreasonable.

The cardinal alleges two errors were made during the trial.

The first is that he was arraigned, which means asked to enter a plea, while the potential jurors watched via video link rather than being in the courtroom.

Pell alleges the judge also made an error when he barred the defence from playing an animation to the jury.

It consisted of a number of dots moving around a floor plan of St Patrick's Cathedral, where Pell abused the choirboys. The dots depicted the movements of the many witnesses after Sunday mass and was an illustration of the defence's argument that Pell couldn't have abused the boys unnoticed.

County Court Chief Judge Peter Kidd did not allow the animation to be played to the jury during the defence's closing address as he ruled it constituted new evidence.

Pell's convictions will be overturned if the Court of Appeal finds that Judge Kidd should have allowed the animation to be played, or that the law required Pell to be arraigned in the physical presence of the jurors.

In that case, the judges could order a retrial.

That is, unless they find it would be unjust to order Pell to face trial a third time.

Pell was found guilty of sexually abusing the boys at Melbourne's St Patrick's Cathedral. ( ABC News: Danielle Bonica )

That will depend on a number of factors including the expense and burden of a retrial, the length of time Pell has already served in prison compared to his likely sentence if found guilty again and, importantly, any risks to Pell receiving a fair trial.

If the court does order a new trial, it will be up to the Director of Public Prosecutions to decide whether to go ahead with it.

If Pell's appeal is dismissed entirely:

If the Court of Appeal judges aren't convinced Pell's convictions should be overturned, he will be transported back to prison to continue serving his six-year jail term.

The 78-year-old spent his birthday behind bars in June and would remain there until at least the age of 81, before becoming eligible for parole.

Pell is not planning to appeal against the length of his sentence.

But his avenues to appeal against his convictions wouldn't be exhausted.

Pell could challenge the Victorian Court of Appeal's judgment in the High Court.

Editor's note: On Tuesday April 7, 2020, the High Court in a unanimous decision upheld Cardinal Pell's appeal and quashed his convictions on all five charges.