The Enlarged Board's decision G1/24 (18 June 2025) established that when assessing patentability, claims remain the starting point, but the description and drawings must always be consulted to interpret them — not only when the claims appear ambiguous.
This aligns EPO practice with early UPC decisions, where description and drawings are always required to support claim interpretation, not only when claims lack clarity.
The case originated from T439/22, concerning Philip Morris' EP3076804 (heat-not-burn device) and the meaning of “gathered sheet”. The term had a narrower meaning in the field, but a broader definition in the description; this divergence was decisive for determining novelty.
Faced with conflicting approaches, the referring Board asked whether Art. 69 EPC/Protocol and/or Art. 84 EPC governed interpretation for patentability, and when description/figures should be used.
G1/24 clarified that:

1. neither Art. 69 EPC nor Art. 84 EPC fully justify the interpretation at issue, but general principles emerge: claims are the basis; the description and drawings must always be consulted for interpretation relevant to Arts. 52–57 EPC;
2. stating that a claim is “clear” already implies interpretative activity, which reinforces the central – not occasional – role of the description and drawings;
3. the approach aims to harmonise EPO practice with post-grant litigation.

Although the underlying case T439/22 is still pending, the Boards of Appeal have already applied G1/24 in T1561/23.
T1561/23 explained what “consulting” the description means.
The case concerned a patent application for PLC controllers claiming a method for executing “auxiliary actions” in real-time. Prior art described systems with “pre-emptive tasks”; the key issue was whether these anticipated the claimed auxiliary actions.
The applicant argued, relying on G1/24, that the description clearly distinguished ordinary tasks (sensor/actuator control with defined timing) from auxiliary actions (complex systems like vision or machine learning with undefined timing).
The Board confirmed the obligation to consult the description, but clarified that G1/24 does not define what weight the description must receive in a specific case, nor does it require adopting description-based definitions for claim interpretation.
In this case, the Board held that the description provided examples rather than binding definitions, and thus rejected the appeal for lack of novelty — confirming the Boards' discretionary power under G1/24.
Conclusions
G1/24 requires that descriptions and drawings contain precise, non-generic definitions.
Standard statements that unintentionally broaden technical terms must be avoided.
All-encompassing patents may still be granted, but are difficult to defend in opposition or litigation.
A patent application should be focused on a specific solution, with descriptions and drawings clear and targeted, avoiding broad interpretations that could later lead to partial or total invalidity or to easy design-around.
Close work with the inventor is essential to define each technical aspect precisely, especially those representing the real quid pluris over prior art.

Patent drafting must again be considered not as a preliminary step to be refined later, but as a document that – from the beginning – clearly and precisely defines the invention's technical features.