On Wednesday, the High Court dismissed an appeal by Sydney-based gaming firm Aristocrat Technologies in a last ditch attempt to restore four patents relating to its pokies.

The patents, which are now revoked, described how users interacted with Aristocrat's gambling machines and how feature games would be triggered during play.

IP Australia first revoked the patents in 2018, finding the claimed invention contained no technical improvements to a computer, merely relating to gaming and gaming rules.

Appeals were launched firstly by Aristocrat and then by IP Australia in the Federal Court and Full Federal Court, leading up to the final attempt by Aristocrat to salvage its patents in the High Court.

The major question in the case was whether an invention could be patented if it simply described a new way of using a computer without changing the fundamentals of how a computer operated.

On Wednesday, the High Court was divided on this question with three judges dismissing Aristocrat's appeal and three judges allowing it. A seventh judge was unable to hand down their decision.

"Three Justices would have dismissed the appeal, characterising the invention, in light of the specification as a whole and the common general knowledge, as nothing other than a claim for a new system or method of gaming," the High Court wrote in a summary of its decision.

"Three Justices would have allowed the appeal, characterising the invention as an (electronic gaming machine) incorporating an interdependent player interface and a game controller which included feature games and configurable symbols. That operation involved an artificial state of affairs and a useful result."

Under the High Court's rules, an appeal is dismissed when judges are equally divided in their opinions.

The case has been keenly watched by intellectual property lawyers across Australia in the hopes it would clarify whether programs can be patented.

Any firm answer to this question would have had ramifications for those who hold a patent for computer-related inventions or those who are considering applying for one.

Kim O'Connell, IP lawyer and partner at King & Wood Mallesons, said the judgment would impact computer inventions and their patents but would not prevent further debate.

"The decision has broader implications for computer implemented inventions, including games implemented on electronic game machines," she told AAP.

"Because the decision was split 3:3, there is likely to be ongoing debate in this area. It is likely we will see reform efforts in this area."

A spokesperson from Aristocrat expressed disappointment in the decision.

"The split decision may not provide clarity on this important aspect of patent law," they said.

"Aristocrat will take time to digest the judgment and consider next steps."

While software can currently be copyrighted in the same manner as literature, music or art, the patenting of computer programs has remained a contentious issue in the legal sphere over recent years.

If permitted, patenting a computer program would grant the patent's owner exclusive rights over the invention, barring anyone else from using it.

This type of restricted access does not typically occur under copyright, which bars copying of the actual code but allows programs to have the same sort of features and functionality provided the lines of code are sufficiently different.

Australian Associated Press