Outside the wall

The art. Painted strokes, tall and leaning shapes, open land, layers of air.

The feeling: a big world with weather and history; brave, a bit wild, still friendly. Six zones sit outside, and Alvheim above them: Sørvika, Sørmarka, Fjellfoten, Nordalen, Fjellet and Alvheim.

A birch slope in front, a lake with three tarred boathouses, a snow peak behind and a waterfall; the princess walks down a path toward them. — The target at the game's camera, outside the wall (Nordalen).

Petter's Fortiche block is the surface. It is in the prompt blocks as PETTER, verbatim.

The rules

Item	Rule
Shape	Tall rectangles and triangles with rounded corners. Silhouettes taper, lean 2 to 8 degrees and are asymmetric. A building is tall and narrow, or long and low, never square.
Scale	Every vista holds one thing at least ten times her height (a tree, a tower, a peak, a giant) and one small sign of folk (a hut, a cairn, a boat).
Composition	Open. One side of the frame runs to a horizon at least 300 m off. Three depth layers: a near frame in the zone's darkest tone, a lit middle ground, a far layer within 15 % luma of the sky and shifted toward its hue. Sky 25 to 50 % of an eye-height frame (Fjellfoten: none).
Palette	The zone's own. Bases muted: mean saturation of a frame at most 0.38, except Sørmarka's evening and Alvheim's glow (at most 0.46). One key colour takes half to two thirds of the frame.
Value	Set by the zone's value key. The shade floor stays lifted: darkest band at luma 0.19.
Light	The zone's hour and weather. Light falls as shapes: a shaft, a pool, a lit slope against a shaded one, in two or three bands.
Brush	Visible strokes following the form; a stroke is 1 to 3 % of a texture's width; three tones with hard edges. On an asset the painted light comes from above and in front only, so it never fights the game's sun.
Line	Thin, coloured, darker than the colour it sits on. Never black.
Materials	Tarred or silvered wood, cold grey stone, turf and moss, wool, rope. Things are weathered and mended.
Night	Land in deep blue and teal with every shape readable, sky green-teal and violet when clear, one fire or lit window per place and nothing else warm.

Do

Three depth layers, each paler and closer to the sky than the one before.
One huge thing and one tiny sign of folk in every vista.
Say the hour and the share of the frame the key colour takes.

Never

Black, gloom, a grave, a skull, a weapon raised, a face without eyes.
A storm with no shelter in sight.
"Warm amber light" in a block shared by all zones.

Three ways to say the same scene

Petter's block run alone drifts brown, stormy and grown-up. Adding the space rules and a stated palette cools it and flattens the far shapes. Adding the northern night gives the strongest frame of the set.

A: the block alone. A pine, a ruin, a muddy road, a gloomy sky. — A. The block and the old rule line only: brown, stormy, gritty, median luma 0.29. Good painting, a grown-up's game.

B: plus the space rules and a stated palette. Cooler, cleaner, flatter far shapes. — B. Plus layers of air, a tiny figure against the pine, a stated palette: median luma 0.36.

C: plus the northern night. Green-teal and violet sky, blue land, one campfire and a wolf. — C. Plus the northern night. The frame to match.

A flat frame, a detailed asset

Two readings of the block exist. The painterly one (above) is far more detailed than the game can draw. The flat gouache reading is a dozen flat shapes, a paper-cut pine and banded hills.

A flat gouache scene: a pale sky, banded blue hills, a lake, a stone tower, one big pine, yellow flowers, a tiny red figure on a road. — Krea 2 Turbo with a short prompt: close to what three.js draws well. Aim the frame (ground, far land, sky, far trees) here; keep the painterly detail for hero assets seen near.

This is a recommendation, not yet a ruling: see open questions.