Writes a settlement letter on the right footing — and warns you when marking it 'without prejudice' won't actually keep it out of court. A genuine settlement letter is normally protected (the judge can't see it), but only if the substance is a real attempt to settle, and even then there are exceptions. The skill picks the correct footing — without prejudice (WP), without prejudice save as to costs (WPSATC / Calderbank), or open — drafts the finished letter, and surfaces the Unilever v Procter &
SkillScore96Maintained
Automatic
◆Legal & Contracts pack
Last verified 8/16/2026
What it changes
Passed 22 of 23 test cases with the skill, and 15 of 23 without it.
Without skill65%
With skill96%
Checks it passed that the model alone missed
The letter header is WITHOUT PREJUDICE rather than save as to costs.
The response states that Scottish tenders are outside the scope of this tool.
The response warns that threatening criminal reporting risks losing without prejudice privilege.
and 4 more in the full report
7 fixed15 passed either way1 still failing0 broke
Pass-rate lift
+30 pp
Tokens
+63%
Agent turns
0%
Response time
-36%
Model gemini-3.6-flashMeasured 8/16/2026v122 of 23 cases passed with skill
Tokens, turns and time describe resource use, not a dollar price.
See it in action
One of 7 test cases the skill fixed. Same model, same prompt, with and without the skill.
1 of 7
Prompt
Please draft a Scottish judicial tender offer letter for a commercial breach of contract action in Edinburgh.
What was checked, without and with the skill
Checked
Without skill
With skill
The response states that Scottish tenders are outside the scope of this tool.
Missed
Passed
case-22 · gemini-3.6-flash · 8/16/2026 · answers are capped and redacted
What's inside
The instructions your model reads when the skill loads.
SKILL.md154 linessingle file
/without-prejudice-drafter
Identify the correct footing: open, WP, or WPSATC.
Apply the right header convention. WP is not protected just because labelled — the substance must be a genuine settlement attempt in an existing or contemplated dispute.
Surface the Unilever exceptions: WP protection is not absolute.
Draft accordingly. Keep open and WP material in separate documents.
Without prejudice / WPSATC correspondence
The three footings
Footing
Disclosure at trial
Use
Open
Yes — fully admissible
Statements of case, demands, pre-action letters not yet in negotiation
Without prejudice (WP)
No — inadmissible to prove liability or quantum
Genuine settlement negotiations
Without prejudice save as to costs (WPSATC) / Calderbank
Inadmissible on liability/quantum; intended to be admissible on costs after judgment
Settlement offers where the offeror wants costs protection but cannot use CPR Part 36 (e.g. Employment Tribunal) or wants Calderbank flexibility
Labelling a letter WPSATC signals the intended footing; it does not by itself secure costs protection. Whether the court reads the letter on costs, and what weight it gives it, is a matter for the court's discretion (CPR 44.2) on the facts. The footing is a proposal, not a guarantee.
When WP protection applies
Three conditions:
There is an existing or contemplated dispute.
The communication is a genuine attempt to settle that dispute.
The parties intended the communication to be confidential.
A letter labelled "without prejudice" that does not satisfy these conditions is not protected. A letter that satisfies them but is not labelled is still protected — the label is evidence of intention, but substance prevails (Rush & Tompkins Ltd v Greater London Council [1989] AC 1280).
The Unilever exceptions (Unilever v Procter & Gamble [2000])
WP protection is not absolute (Unilever plc v Procter & Gamble Co [2000] 1 WLR 2436, [2000] EWCA Civ 11). The categories below are illustrative, not a closed or settled set — the courts treat them as fact-sensitive, so confirm the current scope before relying on any one of them. The court has admitted WP material in evidence in situations including the following. Do not over-extend these; treat anything outside a squarely-decided category as in need of verification rather than asserting protection is lost:
The WP communications show the agreement was concluded — to prove or rebut existence/terms of the agreement.
The communications are evidence of misrepresentation, fraud, or undue influence.
The communications give rise to estoppel.
Without admission, exclusion would act as a cloak for "unambiguous impropriety" (e.g. perjury, blackmail, threats).
To explain delay or apparent acquiescence (relevant to limitation).