Treat each Paper M4-style legal scenario as a dated event chain. For every event, ask which EPC or PCT rule attaches, which deadline it starts, and which remedy applies if the deadline is missed. Then distinguish paired provisions explicitly, such as re-establishment versus further processing, added matter versus clarity, and Paris-route priority versus PCT-phase priority, before writing your conclusion. Readiness checks are in the final section.
Turning a legal fact pattern into a dated event chain
Map every scenario event onto a timeline with the trigger rule named next to it. Conclusions become checkable, and paired provisions stop collapsing into each other.
Start each practice scenario by listing events in order: filing, priority claim, publication, a communication, a missed period. For each event, write the provision that starts or ends a period next to the date. This converts a narrative into a state machine: at each node, the legal situation has a defined status, such as pending application or deemed withdrawn, and only defined transitions are possible from that status.
The timeline method also exposes the conditional nature of the rules. A remedial provision may depend on whether the omission was intentional, on the type of period missed, or on the procedural phase. When you can see the condition as a branch on your timeline, you remember to check it explicitly in your answer instead of asserting a remedy that the facts do not support.
- Event: filing of the first application. Rule attached: the twelve-month priority period begins.
- Event: omission of a required act. Branch: intentional or unintentional? This determines whether further processing is even available.
- Event: communication from the EPO. Branch: which period started, and was a consequence stated?
Art. 121 vs Art. 122 EPC: picking the correct remedy for a missed period
Re-establishment requires all due care; further processing covers unintentional omissions by payment, but both are unavailable for certain excluded periods. Check availability before discussing merits.
These two remedies are adjacent and easy to conflate. Re-establishment of rights under Art. 121 EPC responds to failure to observe a period despite all due care required by the circumstances. Further processing under Art. 122 EPC treats an unintentionally omitted act as if it had not been omitted, against payment of a fee. Because further processing does not require a showing of care in the way re-establishment does, it functions as the broader but more restricted-scope safety net: it is excluded for defined periods, including the twelve-month priority period and the opposition period.
Worked scenario: an applicant misses the period for filing a divisional application after receiving a communication. A plausible mistake is to answer 'further processing, pay the fee' without checking availability, or 're-establishment, show due care' without asking whether all due care was exercised. The better decision is a two-step check: first, is this one of the periods excluded from further processing; second, if re-establishment is pursued, do the facts show a demonstrable cause, such as serious illness documented at the relevant time, rather than an internal office oversight. Why it matters: choosing the wrong remedy means the entire rest of your analysis rests on an unavailable provision, and the argument collapses at the threshold.
| Feature | Art. 121 Re-establishment of rights | Art. 122 Further processing |
|---|---|---|
| Governing standard | All due care required by the circumstances was taken | Omission must not have been intentional; correction on payment |
| Evidence focus | Demonstrable external cause and careful conduct | Mainly that the omission was not deliberate |
| Availability limits | Subject to conditions in the Convention | Excluded for defined periods, e.g. the priority year and the opposition period |
| Typical use in a scenario | Missed period caused by documented exceptional events | Missed act within a routine, still-corrigible period |
Priority: Paris route versus PCT route, and where restoration fits
The twelve-month priority right runs from the earliest filing under Art. 87 EPC and produces the Art. 89 effect of that earlier date. PCT filings enter the European phase later, and restoration has its own narrow conditions.
Trace this example: Application A is filed in January; a later European application filed the following December claims A's priority. Under Art. 87 EPC the right of priority covers applications for the same invention filed within twelve months, and under Art. 89 EPC the effective filing date for novelty and inventive step is January. A common analytical error is treating the later application as if its own filing date governed prior-art assessment, which changes which disclosures count as state of the art and which count as conflicting applications.
Now set the PCT alongside it. A PCT application naming the EPO enters the European phase on a timetable that is longer than the Paris year, so candidates who carry the twelve-month figure from the priority rule onto the European phase transition reach the wrong date. Worked scenario: a candidate computes the European phase entry deadline as twelve months from the international filing date, importing the priority period. The better decision is to identify that the international filing starts a different period for phase entry than the priority rule starts for the priority year, and to compute each separately. Why it matters: conflating the two clocks shifts every downstream event in the timeline, including when amendments can be made and when the application might be deemed withdrawn.
Amendments: Art. 123(2) added matter versus Art. 84 clarity
Added matter asks what the application as filed disclosed, directly and unambiguously; clarity asks whether the amended claims define the protected subject matter clearly. They bar different kinds of amendments.
The Art. 123(2) test asks whether the amendment extends beyond the content of the application as filed, read as a whole. Features may generally come from the description, the claims, and the drawings combined, but generalizing an example into a broad class, or combining features that were only disclosed as alternatives, typically fails the directly-and-unambiguously-derivable standard. Art. 123(3) is the companion bar against extending the scope of protection after grant, which operates relative to the granted claims rather than the filed application.
Art. 84, by contrast, is about whether claims are clear, concise, and supported. A plausible mistake is to argue clarity when the real objection is added matter, because both objections can attach to the same amendment. Worked scenario: an amendment replaces a specific disclosed temperature range with 'elevated temperatures'. The better decision is to lead with Art. 123(2): the broader formulation is not derivable from the single disclosed example, so the amendment is inadmissible regardless of how clear it is. Why it matters: the objection determines the legal test and the evidence you cite; arguing the wrong article invites the rebuttal that your provision simply does not apply to the defect.
PCT phase transitions: what carries into the European phase and what starts anew
Entering the European phase converts an international application into an EP application, but claims, amendments, and subsequent procedural opportunities follow specific rules. Trace each item's status at the transition.
When a PCT application enters the European regional phase, it is processed as a European application, and the earlier international documents stand as the filing basis for added-matter purposes. However, amendments made in the international phase apply only if certain conditions are met, and the EPO may invite the applicant to respond and consider amendments under its own rules. A useful habit is to maintain two columns for every claim set: the version filed internationally and the version on file at the EPO, so the Art. 123(2) reference point is never ambiguous in your answer.
Worked scenario: an applicant relies on a claim amendment submitted during international preliminary examination but never confirmed on entry into the European phase, and treats it as automatically on file. The plausible mistake is assuming every international-phase amendment survives the transition in force. The better decision is to check the status of each amendment at phase entry, note whether the EPO's invitation procedure requires a response, and re-anchor the added-matter analysis to the application as originally filed internationally. Why it matters: the reference text for Art. 123(2) is fixed by the transition rules, and citing the wrong claim set undermines the entire amendment argument.
Using claim interpretation inside revocation and scope arguments
Where a scenario involves validity or scope, anchor the analysis to the statutory grounds for revocation and to the claims' meaning, rather than arguing free-floating technical preferences.
The EPC provides a defined set of grounds on which a European patent may be revoked, including lack of patentability, insufficient disclosure of the invention, added subject-matter, extension of the scope of protection, and certain double-patenting situations. In a legal scenario, your task is to match each alleged defect to a named ground and to the article behind it. A claim that is merely 'broad' or 'commercially risky' is not itself a ground; the argument must be recast as, for example, lack of inventive step over cited prior art or extension of scope relative to the granted claims.
Distinguish interpretive questions from patentability questions deliberately. Claim interpretation asks what the claimed invention covers in light of the description and drawings; patentability asks whether that interpreted subject matter meets the substantive requirements. A plausible mistake is to blend the two, arguing about the meaning of a term while simultaneously assessing novelty against a prior-art document that does not actually fall within the interpretation adopted. The better decision is to fix a defensible interpretation first, state it, and then run the patentability or scope analysis against it consistently. Why it matters: inconsistent readings let an opponent attack your argument twice, once for being too narrow and once for being too broad.
Timeline drill: a scored exercise and a preparation sequence you can adapt
Build one full filing-to-remedy timeline per week from a constructed fact pattern, then score it against a rubric covering rule identification, date computation, and remedy availability.
Exercise: construct a fact pattern with a first application, a PCT filing claiming priority, entry into the European phase, one missed act, and one amendment. On one page, draw the timeline with dates you compute yourself, attach an article to each event, and write one sentence per event stating its legal consequence. Expected observations on self-check: every date is derivable from a named rule rather than asserted; each missed act has an explicit availability check for re-establishment and for further processing; the amendment cites the correct reference text as of the relevant transition.
Self-check rubric, scored out of ten: three points for correctly naming the governing rule for each event; two points for dates computed from the correct starting events; three points for explicitly checking the conditions of any remedy invoked, including excluded periods; two points for distinguishing paired provisions, such as 123(2) versus 84, without conflating them. A suggested sequence over several weeks: week one, timelines for priority and phase entry only; week two, add remedy decisions; week three, add amendment admissibility; week four, combine all elements into one composite scenario and re-score. Treat your rubric scores as learning milestones, not as predictions of any exam outcome. For administrative details such as current registration arrangements and exam logistics, refer to the EPO's own pages rather than secondary summaries.
- Milestone 1: you can compute a priority date, a phase-entry event, and a publication event on a single page without checking a rule text for each step.
- Milestone 2: for every missed period, you automatically write an availability sentence before discussing the merits of any remedy.
- Milestone 3: for every amendment, you state the reference document used for added-matter analysis and justify it.
References and further reading
Use these references to explore the concepts and check the latest information from the relevant organizations.