Last month, the High Court dismissed an appeal by gaming technology provider Aristocrat Technologies over whether computerised components in their electronic gaming machines (EGMs) which triggered a “feature game” constituted patentable subject matter.

The judgment was split evenly between the six justices. Although in theory the ruling should provide more clarity on the increasingly important question of the patentability of computer-implemented inventions (CIIs), the opposing views taken by the two camps of justices may instead create an environment for greater disputation.

Kiefel CJ, Gageler and Keane JJ (the Kiefel CJ plurality) held that Aristocrat’s appeal should be dismissed, on the basis that the invention failed to claim some variation or adjustment to generic computer technology so as to give effect to the new game. They considered that the invention could not be classified as more than a new method of gaming, implemented using existing conventional EGM technology. The justices also found the two-step model proposed by the Full Court (asking first whether the invention claimed a computer-implemented invention and then whether it can be described as an advance in computer technology) unnecessarily complicated the test for whether an invention is patentable subject matter.  

In contrast, Gordon, Edelman and Steward JJ (the Gordon J plurality) would have allowed the appeal, finding that an abstract idea implemented on a computer, which created an artificial state of affairs and useful result, may be a patentable manner of manufacture. They emphasised that the same approach should be taken in respect of methods carried out using a computer as would be taken in considering the implementation of a scheme or idea by any other machine. They considered that the claimed operation of the game controller, displayed through the player interface, was an altered machine involving an artificial state of affairs and a useful result amounting to a manner of manufacture.  

As the Court was evenly split, the Full Court’s decision (that the alleged invention was not patentable) was affirmed by virtue of section 23(2)(a) of the Judiciary Act 1903 (Cth).

The patent

Each of Aristocrat Technologies’ four patents claimed a type of computerised EGM, which is essentially the modern equivalent of a manual slot machine, often available in casinos and other licensed venues for players to insert credits (money or some other form of payment) to commence a game and select the value of a bet. Whether the player wins depends on the occurrences of a winning symbol combination across a set of reels displayed in a grid or matrix, as determined by a random number generator.

The patents at issue incorporated a mechanism that enabled symbols to be configured to trigger a “feature game”, being a secondary game made available to a player on the occurrence of a defined “trigger event” in the base game, enabling the player to win further prizes before being returned to the base game. The patents described configurable symbols which contained a common component and a variable component, the latter of which was indicative of the value of a prize. When the feature game was triggered, the player was guaranteed to win the accumulated value of the prizes indicated by the variable portion of the configurable symbols.

The split Court

The below table identifies key points of agreement and disagreement between the two camps of justices.

Issue Kiefel CJ, Gageler and Keane JJ Gordon, Edelman and Steward JJ
Should the appeal be allowed? No. Yes.
Is a mere scheme, plan, set of rules or discovery of itself patentable subject matter? No.[1] No.[2]  
Can a mere scheme, plan or discovery become a patentable subject matter (e.g. when implemented by a computer)? Yes, if the mere method affect[s] the operation of an apparatus in a physical form.[3]   Yes, if the mere method ‘is practised or used in a way that is embodied in a physical form.’[4]   Rules of a game ‘may be the proper subject matter [of a patent] when combined with physical materials used for playing the game,’[5] regardless of whether the idea of the game is combined with a digital representation or a physical representation of the game.[6]
What test should be applied to determine if a CII is a manner of manufacture? In line with Myriad,[7] it is crucial to first categorise the invention by reference to the terms of the specification having regard to the claim and in light of the common general knowledge (CGK).[8]   The two-step test of Middelton and Perram JJ in the Full Court, that a claim involving a CII could only be a manner of manufacture if it could broadly be described as an advance in computer technology,[9] is not necessary nor helpful.[10]   Instead, in line with NV Philips,[11] ‘the issue is whether the implementation of what is otherwise an unpatentable idea or plan or game involves some adaptation or alteration of, or addition to, technology otherwise well-known in the common general knowledge to accommodate the exigencies of the new idea or plan or game.’ [12] The starting point is the characterisation of the relevant claim which requires consideration of all of the integers of the claim.[13]   Rather than use the two-step test of Middelton and Perram JJ, instead the relevant question is toask whether, properly characterised, the subject matter that is alleged to be patentable is: an abstract idea which is merely ‘manipulated on a computer’ (in which case the CII will not be patentable); or an abstract idea which is ‘implemented on a computer to produce an artificial state of affairs and a useful result’ (in which case the CII will be patentable)[14]     Anartificial state of affairs and useful result’ may be:[15] ‘a physical change in something, but it need not be’‘an improvement in computer technology, but it need not be.’‘created by “the way in which the method is carried out in the computer”’   A CII should not be treated any differently from a scheme or idea implemented by any other machine, but in both cases the invention must do ‘more than merely manipulate an abstract idea.’[16]
Is the claimed invention a manner of manufacture?   No, because the claimed inventiondoes not disclose any technical contribution to either computer or gaming technology outside the CGK. At best, the claimed invention contains a new game which may enhance player enjoyment but that cannot be said to amount to a technical contribution or to solve a technical problem in the field of computer or gaming technology.’[17]   There is nothing new or inventive about the interaction between the configurable symbols and the game.[18]The claimed invention is ‘no more than an unpatentable game operated by a wholly conventional computer, using technology which has not been adopted in any way to accommodate the exigencies of the game or in any other way.’[19] Yes, because ‘the claimed operation of the game controller, displayed through the player interface, is an altered EGM involving an artificial state of affairs and a useful result amounting to a manner of manufacture.’[20]     Core feature of integers 1.7 to 1.12 provide the invention with its ‘alleged novelty and inventiveness’.[21] These integers made up the different components of the “game controller”, which included the configurable symbols and feature games, and were ‘emphatically not part of the CGK.’[22]

Effect of the decision

The split decision underscores the Court’s ongoing struggles to map existing jurisprudence on the concept of ‘manner of manufacture’ that was developed before computers had even been conceived of, onto patents involving CIIs.

Further, due to diametrically opposing views of the two equally divided camps of justices, the precedential value of the judgment in guiding lower courts going forward is unclear.  In this regard, it is worth noting that two justices from the Kiefel CJ plurality – Kiefel CJ and Keane J – will be retiring from the bench in the near future (Keane J in October 2022 and Kiefel CJ in January 2024). Further, Gleeson J did not appear to hear or rule on this case due to illness. As such, the decision as a whole does not provide the clarity of approach that patent attorneys, lawyers and would-be patentees alike were seeking, and it may not be long before another patent involving a CII comes before a differently constituted High Court for further consideration.

The authors wish to thank Amy O’Bryan, Lawyer, for her contribution to this article.


[1] Aristocrat Technologies Australia Pty Ltd v Commissioner of Patents [2022] HCA 29 (Aristocrat Technologies) at [22] – [24] (citations omitted).

[2] Ibid at [116] 

[3] Ibid at [22] (citations omitted).

[4] Ibid at [117] (citations omitted). 

[5] Ibid at [118] (citations omitted). 

[6] Ibid at [119] (citations omitted). 

[7] D’Arcy v Myriad Genetics Inc (2015) 258 CLR 334 (Myriad) at 342-343 [12], 385-388 [138]-[145].

[8] Aristocrat Technologies at [77].

[9] Ibid at [77].

[10] Ibid.

[11] N V Philips Gloeilampenfabrieken v Mirabella International Pty Ltd (1995) 183 CLR 655.

[12] Aristocrat Technologies at [77].

[13] Ibid at [101] – [102].

[14] Ibid at [122].

[15] Ibid.

[16] Ibid at [153].

[17] Ibid at [84].

[18] Ibid at [79].

[19] Ibid at [76].

[20] Ibid at [154].

[21] Ibid at [146].

[22] Ibid.