The Brinemarch Hex Run
by Lavamuppet
The Brinemarch
Brinemarch is a low-fantasy 1 hexcrawl 2 setting for the fog-shrouded coast of the greened Antarctic coast. The Brinemarch region faces the Indian Ocean, located at 70°E latitude in the Mac. Robertson zone.
PREFACE
This is a record of a longer learning process. This blog documents the design values, goals, and choices behind The Brinemarch Hex Run for later reflection. I have drawn fantasy and RPG maps since childhood; this project is an opportunity to learn how to communicate dreams of adventure, danger, and exploration in a new medium. A current edition of the playable material will be available at lavamuppet’s itch.io.
Contents
THE OSR ANTARCTICA DESIGN JAM
The Brinemarch Hex Run was created for the 2025 OSR Antarctica Design Jam as a survival-oriented hexcrawl in a low-fantasy setting. One requirement of the jam was that entries use role-playing systems that are freely and publicly available.
The goal is to contribute to the jam
100 discoverable locations keyed to a map.
Signals for meaningful navigation choices
Travel hazards
A set of rules-agnostic tools to assist whoever runs the game.
Sufficient lore to make a pitch for the table
DESIGN GOALS OF THE BRINEMARCH RUN
Rather than follow a single TTRPG (Table Top Role Playing Game, vs video game RPG) ruleset, this setting is written in an OSR (Old School Revival) 3 system-agnostic style. It is also designed to work well-enough (read: fun-enough) with rules-light systems.
Knave, Cairn, Into the Odd, Basic Fantasy 4th ed, Old School Essentials, SRD, or similar frameworks.
Guidelines Which I will Inevitably Break
Don't name game mechanics.
Don't track conditions
Do use descriptive tags
Don't describe assumed consequences
Do describe breaking points
Do assume adjudication
DESIGN SUB-GOAL: USER ACCESSIBILITY
The formatting and structure has the following aims
- minimize scrolling or page flipping, using inline information and foot notes.
- support navigation using nested hierarchy of information
- support readability with visual hierarchy and UX principles.
- support aesthetics by using prose and pictures as landmarks.
- commitment to feedback and revision for accessibility as the project proceeds This is being developed in public, with revisions informed by play, feedback, and further research. 4
These objectives apply first to analog, then digital copy, and then the needs of table top simulator contexts (Dec. 14, 2025).
THE REGION SIZE DESIGN PROBLEM
Brinemarch covers a relatively large region for a hex crawl 2 (though it is average size for most of the Antarctica Jam claims), it is roughly the size of South Carolina (32,020 square miles with 30,061 sq. mi. of land).
The size provides: -wilderness survival tension
- weeks-long journey -weather gradients -room for geopolitical tension -support for megafauna and apex predators
Any document made separately from the https://itch.io/jam/antarctica-jam will be organized by chapters of either watersheds, terrain type, or by tile 5
The rough distribution of [tiles] looks like this roughly:
_ _ _ A. B. C. D. E. F.
_ _ G. H. I. J. K. L.
_ _ _M. N. O. P. Q. R.
_ _S. T. U. V. W. X.
Y. Z. A&. AA. AB.
Terrain
- Mountains: I, N, T, O, U
- Forests: A, B, C, G, H, I, M, N, O
- Some coniferous stands in H, N, O
- Arid Flats (Desert/Salt): Z, A&
- The rest is plains of various elevations.
- The outer coastline tiles include: F, L, R, X, W, V, U, A&, Z, Y
For reference:
| Corner | (row_index, col_index) | Description |
|---|---|---|
| NW | (109, 531) | Top left |
| NE | (109, 584) | Top right — extended for island |
| SW | (143, 531) | Bottom left |
| SE | (143, 584) | Bottom right — extended for island |
DESIGN FLAVOR
Most of my experience in gaming, reading, and writing comes from European and North American fantasy traditions. Defaulting to those conventions is easy, and escaping them entirely is neither possible nor desirable. They provide a shared language and recognizable expectations at the table.
Nevertheless, there is no inherent reason a hexcrawl must reflect only the geography, ecology, or cultural baselines most familiar to the designer.
The aim is for Brinemarch to present an inhabited, reactive, and dangerous landscape shaped by its situation in the Southern Hemisphere.
ASSUMPTIONS FOR PLAYERS
The goal is to support hexcrawling in a landscape that routinely reconfigures roads and landmarks. Some characters may be familiar with the ways of the land, but most will not.
Player characters are assumed to be agents of an outside power, such as the Empire or its chartered Company, engaged in exploration, trade, or extraction. These agents will find the local situation incoherent and resistant. Characters with established relationships to the land will, in turn, find the Empire and the Company dangerous and hostile.
The guiding design principle is that there is always tension between what is expected and what emerges. How that tension is resolved is left to play.
The Brinemarch Run
Player Introduction
Now you are coated in mud, gathering tubers in black water. The mosquitoes are finally indifferent, but clouds of tiny flies bite your neck bloody.
In the reeds you find a plank of wood, perhaps from a shipwreck or a forsaken wagon. Deep scratches resolve into familiar lines: Queens Bay, St. Bastion Island, rivers, mountains. It is enough to hope.
The sun moves in frustrating circles this time of year. You cannot yet tell whether this river runs to the coast or toward the Red Forest. The trails are few. There are rivers aplenty.
You roast what you gathered. A pair of yellow-winged sun-crows watches the tiny fire with judgement. Across the water, the Terror Bird paces the far bank, unwilling to enter the bog, eyes never leaving the fire.
This is as safe as you will get tonight. Night never comes, but fatigue does find you. You lie down in the only dry spot you can find. You pull up your hood, eyes pressed shut against the midnight light. You dream of the earth swallowing a castle like the Legend of Fort Aardwolf.
Will you ever find dry ground again? Can you find refuge before the frost? How will you earn passage? In what way will they accept this kind of return home?
Setting Assumptions:
Brinemarch is set on the coast of a greened Antarctica,which means glaciers are gone; the weather is perpetually cloudy and misty, a storm may take shape without notice, or worse a malestrom returns unseasonably.
The local nations maintain wards that prevent the return of ancient princes of oppression.
The Brinemarch was not the first place they arrived. It was a long time before the rivers of Brinemarch finally met the Tide Folk, the Canoe Folk, and people who call themselves the Namers of Stars. Together, they gave this region a name in their own tongue, “Woven Shelter” or "Sacred Wall". To you, it sounds a bit like “Brinemarch.”
World history follows an Iron Age empire with caravels and colonial outposts, gunpowder, clockwork devices, but not industrial steam power.
Such an empire will have built a castle on an island with a natural harbor here and uses it as a base to explore and exploit the Antarctic interior. The imperial bureaucrats will call it New Sanctuary City, sailors will call it Brinemarch Harbor. These outsiders wrestle for resources and land, and their recklessness will disturb ancient powers. The locals call them, the People of the Flag.
Hexcrawling Assumptions
Reroll weather every hex entered.
1 encounter or event roll per hex traveled, or day at minimum.
1 “what’s here?” sentence per keyed hex
Getting lost on a bad roll
BASELINE WEATHER PROCEEDURE
Roll 2d6, take the lower roll. Add Wind and Lightning to Doubles **1d6 | Brinemarch Weather **
| 1 | Clear Skies, full visibility.
| 2 | Mist, visibility reduced to 1 hex
| 3 | Cold rain; waters rise (travel speed: 1/2 on land, 2x on river)
| 4 | Heavy Rain, floods (can canoe anywhere)
| 5 | Hail Storm
| 6 | Snow (arcane, rivers freeze for now) |
Magic
The greened Antarctica is not completely thawed. It remains only mostly thawed. Small glaciers and extensive permafrost cover the Northwest quarter of the map. Fantasy elements come from under the ice. The history of the elves and dwarves ends hundreds of thousands of years ago with the “Abominable Freeze 6 that pause terrestrial life in a global cryogenic sleep,
As the glaciers receded mortals woke up from the cryogenic sleep wake up cranky, confused, coughing, and poorly adapted to a new world. Most perished after only a few hours. With help, some have survived and their children continue on in specialized conditions. These are gnomes, goblins, orcs, elves, dwarves, a dragon or two, and other mythical beasts.
Notes to self
for revision:
magic as an intrusion on a familiar world.↩
Hex crawl (two words) will refer generally to games that use a hex map to support play. Hexcrawl (one word) will refer specifically to games that cannot function without hex-by-hex exploration. Hexcrawling refers to gameplay procedures that interact with a hex map or its territory.↩
An online search for "What is OSR" will reveal many debates that agree on a few things. One thing that appears to differentiate Old School Revival (OSR) style modules is the use of descriptions of situations, risks, and consequences which assume adjudication at the table rather than using preset results, or representing outcomes with abstract game mechanics.↩
Revision log TBA. Credit to contributors and beta readers TBA↩
The term [tile] here refers to a set of 61 or a 9x9 hex. The smaller travel hexes are 6 mi to a side, roughly 7 miles from center to center). Sub-regions will be organized out of tiles.↩
homage, with respect to the Magician's Nephew and the Abominable Word.↩