Dr David Eyre

September 2026

In these proceedings the European Patent Office (EPO) Technical Boards of Appeal (TBA) revoked a patent owned by Husqvarna AB following an appeal brought by Brokk AB.   

With regard to assessing amendments for addition of matter under Article 123(2) EPC the TBA were clear that the decisive test with respect to added matter remains the “gold standard” test of G2/10 as to whether subject matter is “directly and unambiguously derivable from the application as originally filed”. In contrast, the Board expressly stated that the traditional “essentiality test” was not applicable in this case.  

The decision also highlights the increasingly strict procedural approach adopted by the Boards of Appeal under the 2020 Rules of Procedure of the Boards of Appeal (RPBA) whereby claim requests that are not properly substantiated risk being refused admission altogether. Finally, the Board found that the remaining claim request lacked inventive step because it represented an obvious modification of the prior art. As a result, the patent was revoked in its entirety.  

Thus, for patentees and opposition/appeal practitioners, the case serves as a further reminder that submission of claim amendments during appeal proceedings requires both clear basis in the original disclosure and compliance with the RPBA.  

Background 

European patent no. 3365744 concerned a remote-controlled demolition robot developed by Husqvarna AB. The opposition was brought by Brokk AB, a well-known competitor in the demolition robotics sector. Although the Opposition Division had previously maintained the patent in amended form, Brokk appealed the decision.  

A “Gold Standard” for Added-Matter  

The most significant aspect of the decision concerns the Board’s treatment of amendments under Article 123(2) EPC with respect to addition of matter. 

During the appeal, Husqvarna sought to defend amended claims in which certain features from the originally disclosed embodiment (“top control switch” and “outriggers” recited in original claim 1) had been removed.   

Husqvarna argued that the omitted features were not essential to the invention and therefore could be deleted without creating new subject matter. This is in line with the “essentiality test” that has historically been relied upon as a justification for removing claim features. As noted in the EPO Guidelines, section H.V.3.1, items (i) to (iii), under the essentiality test, an amendment might be considered permissible where: 

• the feature was not originally presented as essential; 

• the feature was not indispensable to the operation of the invention; and 

• the removal of the feature did not necessitate further modifications. 

However, the TBA concluded that the amendments resulted in added subject matter because the amended combinations of features were not directly and unambiguously disclosed in the application as filed. That is, they did not meet the “Gold Standard” test of G2/10. Further, importantly, the TBA expressly stated that the “essentiality test” was not applicable. 

Thus this case highlights the shift in EPO case law towards the “gold standard” test and Decision T 0417/25 illustrates how this strand of case law and practice is developing. The TBA’s reasoning suggests that arguments based solely on the perceived non-essential nature of a feature are unlikely to succeed where the amended subject matter lacks a clear basis in the original disclosure.  

Accordingly, while the “essentiality test” is still given in the EPO Guidelines (as noted above), its reliability in practice is called into doubt. 

Auxiliary Requests: Increasing Procedural Rigour 

This decision also contains an important procedural lesson. A broader trend under the RPBA 2020 is that parties submitting claim requests are increasingly expected to provide a complete explanation of: 

• why a request has been filed; 

• which objections it seeks to overcome; and 

• why the amended claims should be allowable. 

In line with this stricter practice, the TBA declined to admit Auxiliary Requests 2 and 5, finding that the proprietor had not sufficiently substantiated them and had failed to explain how the amendments addressed the issues raised on appeal.  

Thus the days when parties could simply file multiple claim requests for fallback positions and expect them all to be considered appear to be fading. The Board’s approach in T 0417/25 demonstrates that unsupported auxiliary requests may never be examined. 

For opposition and appeal practitioners, the procedural message is clear: every auxiliary request should be accompanied by an explanation of its purpose, legal basis, and why it is allowable. 

Inventive Step 

One auxiliary request was found not to add matter, and its inventive step was considered. However, the TBA concluded that the claimed subject matter represented no more than an obvious modification of a suitable starting point and therefore lacked inventive step under Article 56 EPC.  

This conclusion reflects a recurring theme in mechanical, robotics and control-system cases. Where a claimed modification addresses a predictable engineering problem and a cited document already points towards the proposed solution, the EPO is likely to regard the development as routine optimisation rather than a genuine, inventive contribution.  

Conclusion 

In conclusion, this is a decision about amendment practice rather than robots. While the patent related to a remote-controlled demolition robot, the significance of T 0417/25 lies elsewhere. 

This decision confirms that: 

• the “gold standard” remains the decisive test under Article 123(2) EPC; 

• the “essentiality test” is increasingly unlikely to rescue amendments that lack a clear basis in the application as originally filed; 

• inadequately explained auxiliary requests face a real risk of non-admission during appeal proceedings; and 

• patentees should be able to identify clear basis for every amendment they seek to make.  

Thus T 0417/25 joins a growing body of Board of Appeal decisions emphasising both substantive discipline under Article 123(2) EPC and procedural discipline under the RPBA 2020.