Module Design

How a Tidewright module is built — the mandatory slots, and why each one exists

Where this comes from

Three modules, three authors, deliberately different in scale — read in full and compared slot by slot. Nothing below is invented; each rule is a defect that showed up as a real failure in at least one of them, or a technique one of them did well enough to steal.

The two layers

Every session ships two pages, and the split is the point. Sessions are peers — there is no page above them.

• The one-sheet (sN-sheet.html, from sheet.html) — the primary page. Roughly one page: where we are, what happened last time, how the night opens, what could happen, who is in it, what might come for them, and what is on offer. This is what you land on and what you hold at the top of the night.
• The prep read (sN-<slug>.html, from scene.html) — long-form, read the night before. Reasoning, atmosphere, the numbered read-alouds in clock order, Developments, the behind-the-screen truth. Prose is allowed here.

A third kind of page exists only when it earns itself: a fight page, owned by no session, holding one fight in full — see the four slots. Three exist: session 1, session 2 and session 3.

There is no module run-sheet. The arc-level slots below still have to be answered — they just live in the session that first needs each answer.

Session-level slots — the one-sheet

Slot names are flat on purpose — changed 8/19/2026. They were “Scenes in play”, “Who’s here” and “What might come up the sand”, which read as prose rather than as a schema — and the last of those was the strand’s prose, so a session set in a taproom had nothing coming up any sand and quietly drifted to “What might come”. A slot name is a label a DM scans for at the table, not a line of writing. Keep the flavour in the beat names and the h-notes, never in the slot.

Seven slots, in this order. The order is the point: it runs from orientation to the opening line, and only then into what might happen. Six are required; Numbers is optional and near-mandatory for any session with a fight.

There is no recap slot — removed 8/22/2026. Slot 2 was Last time, a postmortem of the previous session written into the top of the next one. The prep read carried a second copy as What carries over. Every session now has its own recap page, so both were the same facts written a third time on the page you open to run tonight. What happened last time lives on the recap and nowhere else. The sheet links to it from the rail.

Fight-page slots — four, and most of them are short

A fight gets its own page when it has something beyond a statblock and a hit-point total — a second wave, a terrain rule, a guest character, an ending that is not “kill it.” Anything simpler stays in the one-sheet’s Monsters foldout and no page exists. It is named after its episode — sN-fight.html, beside sN-sheet.html and the prep read — and titled the same way: Reading the Marks — the fight. Do not give a fight a name of its own; a page called The Skirmish tells a DM scanning the rail nothing about which night it belongs to.

It is the only place the fight’s numbers are written down. The sessions keep a one-line summary at the point of use and link here. The read-alouds stay on the prep read in clock order — boxed text is the night’s voice, and only the mechanics move.

Four, and no fifth. Seven were drafted — a shape, tactics, and a numbers table as their own sections — and it read as information overload for a fight that is one creature in a room. The shape is the glance’s one rule, tactics belong to the creature, and for most fights the statblock is the numbers.

The environment prompt

Every fight page carries a query for the image generator that makes the battle map, in a .prompt block so it can be taken in one click. It is short and general on purpose.

• The opener is fixed, and is never rewritten: Generate an image that is a D&D battle map in 16-bit pixel art, in the style of Chrono Trigger.
• Then the kind of place, in general terms — a fishing port town at night, a cooperage yard, a taproom. Not the scene. The kind of place.
• Then the surroundings only — five or six things visible from above. Sand, docks, a sea wall, upturned boats, torches.
• Wide and zoomed out (the norm since 2026-09-13): frame it as a wide, zoomed-out overhead view, and add one sentence saying the features are small, with open ground around them. Gridded by its features (a cask, a gangplank or a grave’s width is one square), a map should come out around fifty squares across. The first close-up maps came out about fourteen squares across, and four tokens filled them.
• Never people, and say so: end on No people. No grid lines, no text. Owlbear draws its own grid, and a generator stamps labels on anything flat. A crowd is on the page as text and is terrain, not scenery.
• Never story props. The funeral board, the unlit lamps and the bread on the offering stones all came out of the first draft. They either do not render or render wrong.
• About fifty words. A first attempt ran to a hundred and thirty and was describing a moment in a story rather than a place, which is what makes a generator produce nothing usable.

Arc-level slots — and where they live

These are the questions an arc has to answer. Until 8/19/2026 they sat together on a module run-sheet; now each goes to the session that first needs it, and later sessions link back. Three are new, marked with the module that taught them.

Placing one: the session where the fact is first true at the table, not the session that talks about it most. Premise and the truth go to the opening night, because its ending depends on them. Failure goes to the night whose fight can be lost. Endings go to the last night.

Scene-level slots — the prep read

Page order — required, and the one this repo keeps breaking

The slots above say what a prep read holds. This says where it goes on the page, because a page can carry every mandatory slot and still be unreadable if they are in the wrong order.

Prose rules

Everything that is not read aloud

Two registers, and only one of them gets to be literary. Read-aloud, opening monologues and quoted NPC speech are spoken word — they are performed, and the writing there earns its keep. Every other word on every page is scanned mid-session by a DM who is looking for one fact, and it is written flat: clear, concise, straightforward, no flowery filler.

• State the beat, do not argue for it. “Do not recap”, not a paragraph on why refusing to acknowledge the gap is the strongest thing you can do.
• No bolded lead-ins that turn a list back into prose, no clauses hung off dashes doing atmosphere, no metadata line added “for completeness.”
• Slot names are flat labels — Scenes · NPCs · Monsters · Numbers · Rewards · Environment. Flavour lives in beat names, h-notes and read-alouds. Nowhere else.
• Fewer slots than feel right. If a section needs a paragraph to explain why it exists, cut the paragraph; if it still needs one, cut the section.
• Say a thing once. A fact written on two pages will diverge, and the copy a DM happens to open is the one they will run.

Read-aloud

• Second person, present tense, 3–5 sentences, senses first.
• No mechanics. No DCs, no HP, no numbers the players couldn't perceive.
• End on something that moves, or something wrong — and stop at the moment the party can act. Where it is natural, end on the question itself: the box’s last line points at them, or an NPC in it asks them something they have to answer. A roll never goes inside the box — that is the no-mechanics rule above — so when a beat wants one, it goes on a cue line immediately under the box, naming a DC that is already in the Numbers table. Not every box: mid-combat boxes, where initiative is already running, and a confession or a curtain that is meant to hang, all end better without one.
• Split it around combat. Threat first; the carving on the wall after the fight. Nobody absorbs atmosphere while rolling initiative. (Delian)
• If the read-aloud is describing geometry, you need a map instead. This is the failure mode of Wild Sheep's tower — 200 words of floor plan read aloud because there was no image.
• Layer with conditions rather than one wall: “If Sildar Hallwinter is with the party, add:” (LMoP)

Which DCs to write down

Lost Mine specifies every check; Wild Sheep specifies about five, and plays fine. The test: write the DC when failure has a consequence you'd have to invent under pressure. The trap, the locked door, the talk-him-down. Ambient checks the DM can improvise don't need a number.

When you do write one, write the whole chain — passive threshold, active DC, the save, the condition, the damage, and how it ends. Then put it in the Numbers table on the card.

Monsters

• Reskin before you invent. 2014 MM statline at the right CR, renamed and reflavoured. At most one or two house tweaks, each labelled.
• Reflavour by changing the fiction, not the math: “the rigging IS the web — it feels you touch a line.”
• Rosters as formulas. 1 + #PCs, with a floor and a ceiling.

NPCs

Every named antagonist gets a grievance — one sentence that makes them right from where they stand. Not a justification; a position. This is the single highest-value 200 words in Wild Sheep, and it's why anyone remembers that module.

Beyond that, three fields from Trilemma, all required on any NPC with a page:

• Wants · Needs · Has. Wants is what they'll trade for and say out loud. Needs is the deeper drive they may not name. Has is the inventory of everything obtainable from them — objects, services, permissions, and facts, including intangibles like “the right to declare people friends of the Raindrinkers.”
• Standing. Disposition is relational, not a friendly/hostile dial — write their position against the other named NPCs, so choices with one person move another. “Befriend Tatien and Ulroch will be against you; earn Tatien's enmity and Ulroch may yet help you.”
• Description & Mannerisms. Description is a comma-run of sensory tags, never a paragraph — “Gaunt, paper-thin skin, bald, smells of soil, dirt under his fingernails” — because you read it mid-sentence. Mannerisms are two or three physical tics, kept separate from the verbal tell.

On the card, one line each: role · manner · tell · wants · has · grievance. The tell is the verbal habit you actually play them with — Krell says ships are “taken,” never sunk.

Numbers

Concrete, always. 50 gp, not “a reward.” ~80 gp of unlogged sundries, not “some valuables.” If a reward is deliberately withheld — Wild Sheep's deadbeat wizard is a good joke — that's a choice you make once, not a way to skip the arithmetic.

Worked examples

From The Ship That Didn't Sink — the campaign's first module, written before this spec, which already got most of it right. The module itself was retired in a fresh start and no longer exists in this repo (it's recoverable from git at the tag pre-campaign-reset). The examples are kept because they're self-contained and because they're the reason this spec is concrete rather than abstract.

Optional — considered, not adopted

Techniques that survived the survey but were deliberately not made mandatory. Reach for any of them when a module wants it; none is a requirement, and nothing is out of compliance for lacking one. Recorded here so the reasoning is on file and nobody re-litigates it from scratch.

What we don't do

• No just-in-time rules teaching. The Delian Tomb stops to explain ability checks and surprise at first use. That's right for a module aimed at first-time DMs and dead weight here.
• No six-route redundancy. Lost Mine gives one fact six delivery paths because it's written for unknown tables running it out of order. Tidewright modules run for a known table in a known order — two routes per critical fact is the standing number, and the alert chain does the rest.
• No custom stat blocks by default. Reskin. The lineage has to stay auditable.
• No canon edits from module work. Modules reference canon; they never restate or revise it. If a module seems to need canon changed, stop and raise it.
• No prose on the one-sheet. If it is a paragraph and it is not the opening monologue, it belongs on the prep read.
• No system-neutral phrasing. Trilemma and Serpent Kings both stay system-agnostic on purpose. We are committed to 5e 2014 with MM reskins — that's a strength, and hedging it would cost the auditable lineage.
• No player-teaching lessons. Serpent Kings teaches its players what a dungeon is. Our table isn't new.
• No hard page limit. Trilemma's one-spread constraint is a superb editing forcing-function, but the two-layer split already solves the problem it solves — the one-sheet is our page limit.

📐 Infrastructure · module design spec · start from the one-sheet template and the prep read template