International patent practice creates drafting challenges when specifications must satisfy both European and US requirements. Many practitioners believe EPO practice requires explicit problem-solution language that criticizes prior art inadequacies. This misconception may lead to using problem-solution language in US applications that creates risks such as prosecution history estoppel and claim scope limitations — risks that are entirely avoidable with proper drafting strategies.
The EPO’s Problem-Solution Framework
The European Patent Office employs a mandatory problem-solution approach for examining inventive step, but this requirement applies to examiners’ analytical methodology, not to applicants’ drafting format. The EPO requires examiners to apply a three-step framework: identify the closest prior art, determine the objective technical problem solved by the claimed invention relative to that prior art, and assess whether the claimed solution would have been obvious. Critically, examiners must apply this analysis regardless of how the application is drafted, and they retain full authority to reformulate the objective technical problem based on their independent assessment.
However, what the EPO requires from applicants under Rule 42(1) EPC is more modest: the description must specify the technical field, indicate background art with citations, disclose the invention in sufficient detail, and indicate the invention’s advantageous effects with reference to the background art. Notably absent is any mandate to explicitly state “the technical problem” in a separate section or to characterize prior art “inadequacies” or “failures.” Many successful EPO applications use neutral background language describing the technical field, clearly disclosing what the invention achieves and its technical effects, and allowing the examiner to formulate the objective technical problem during examination. The spectrum of acceptable EPO drafting ranges from minimal, neutral descriptions to explicit problem-solution framing, as long as the drafts meet EPO requirements that the invention and its technical effects are adequately described.
Global Variation in Patent Examination Approaches
Patent offices worldwide employ varying methodologies for assessing inventive step or non-obviousness, though a comprehensive description of current examination practice in each jurisdiction is beyond the scope of this article. The United States Patent and Trademark Office does not employ a problem-solution framework for assessing non-obviousness, instead determining obviousness using teaching-suggestion-motivation analysis and the factors established by the Supreme Court in Graham v. John Deere Co. This creates a challenge for US practitioners managing international patent families: drafting strategies that may align with examination practices in some jurisdictions can create significant vulnerabilities in US prosecution and enforcement.
Risks of Using Explicit Problem-Solution Language in US Applications
Incorporating explicit problem-solution language into United States patent applications creates multiple prosecution and enforcement vulnerabilities that can significantly narrow patent scope. First, explicit statements that prior art “fails to solve” particular problems or suffers from specific deficiencies may be interpreted as applicant admissions about the prior art and the invention’s scope.
Second, detailed problem descriptions can trigger written description issues under 35 U.S.C. § 112(a) by suggesting the invention is coextensive with the solution to the articulated problem. If claims are broader than necessary to solve the stated problem, examiners may argue that the specification fails to demonstrate possession of the full claim scope.
Third, criticizing prior art capabilities creates roadmaps for examiners to formulate obviousness rejections under 35 U.S.C. § 103. By explicitly identifying what prior art allegedly cannot do, applicants may inadvertently highlight combinations or modifications that would overcome those stated limitations, providing rejection theories that might not otherwise have been apparent.
Fourth, under principles established by the Supreme Court in Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., strong problem-solution framing may increase prosecution history estoppel risks that can limit or eliminate doctrine of equivalents protection during litigation. When prosecution records show applicants distinguished prior art based on specific problems solved, accused infringers can argue that any device not solving that problem in substantially the same way falls outside patent scope, even if structurally similar to the claims.
Fifth, problem statements may create enablement issues if problem framing suggests applications or embodiments not fully enabled in the specification, or implies certain embodiments are superior without adequate disclosure of implementation. These risks persist throughout the patent’s lifetime, affecting not only initial prosecution but also claim construction during litigation, validity challenges in inter partes review proceedings, licensing negotiations, and patent valuation.
Drafting Strategies for US Applications
US practitioners can employ strategic drafting techniques that both minimize risks associated with explicit problem-solution language, as well as satisfying EPO Rule 42(1) disclosure requirements. A first approach involves shifting from problem-deficit framing to benefit-advancement description. Rather than stating prior art systems “fail to provide adequate sensitivity,” the disclosure may describe that “certain disclosed embodiments provide enhanced sensitivity enabling detection of concentrations below ten parts per million.” Such a formulation conveys technical information required by Rule 42(1) EPC—indicating advantageous effects with reference to background art—without characterizing prior art as deficient.
A second approach attributes technical challenges to application environments rather than to prior art inadequacies by describing contexts rather than failures. Instead of “conventional sensors cannot operate at high temperatures,” the disclosure may say “certain industrial applications involve exposure to temperatures exceeding 500 degrees Celsius” and “disclosed embodiments may maintain measurement accuracy at temperatures up to 600 degrees Celsius.” Such an approach identifies the technical landscape and the invention’s capabilities without admitting prior art limitations, while still providing contextual disclosure that EPO examiners need to formulate the objective technical problem during examination.
A third approach employs consistent hedging language including “may provide,” “can enable,” “in certain embodiments,” and “in some implementations” throughout specifications, in order to prevent any single embodiment or advantage from limiting claim scope. A fourth approach maintains background sections that describe what exists in the technical field rather than what is wrong with it, and includes explicit disclaimers that background information is not admitted to be prior art or material to patentability. A fifth approach describes advantages, using objective technical metrics rather than subjective characterizations, quantifying benefits with specific data where possible, and including catch-all language stating that not all embodiments necessarily provide all advantages. A sixth approach drafts independent claims at the broadest reasonable scope first, then writes a specification supporting those claims without introducing unnecessary limitations through problem-solution language. Some or all of these approaches may be used in a single application, as befits the subject matter of the disclosure.
Key Takeaways for a Unified Drafting Approach
The key insight for US practitioners handling global patent families is that neutral, benefits-focused language satisfies EPO disclosure requirements because EPO examiners will independently formulate the objective technical problem during examination regardless of specification language. Use of such language eliminates the traditional perceived trade-off between EPO-optimized and US-optimized specifications, because carefully drafted, neutral specifications work effectively in both EPO and US jurisdictions, maximizing prosecution flexibility while minimizing litigation vulnerability.
For companies prosecuting international patent families, adopting neutral, benefits-focused drafting strategies can reduce unnecessary risk in U.S. practice while fully satisfying EPO disclosure requirements. Contact Conley Rose to discuss how your organization can align its global patent drafting approach with both U.S. enforcement priorities and European examination standards.