diff --git a/Core/Scripts/BLUEPRINT_FORMAT.md b/Core/Scripts/BLUEPRINT_FORMAT.md
index 87eb253..91e8f7b 100644
--- a/Core/Scripts/BLUEPRINT_FORMAT.md
+++ b/Core/Scripts/BLUEPRINT_FORMAT.md
@@ -55,7 +55,7 @@ Every section: `[u32 tag][u64 payload-length in bytes][payload]`.
 | `HGTS` / `0x53544748` | `MapSize²` × `f32` height, **X outer / Y inner** | Mandatory. The second index is the map's north/south axis; the server consumes it as world **Z**. (This axis convention was never written down for v1 — it is now normative.) Length must equal `4·MapSize²`. |
 | `BIOM` / `0x4D4F4942` | `MapSize²` × `u8` biome ordinal, same pixel order | Mandatory. Ordinals from `Enums.cs::Biome` — **append-only, never reorder** (the ordinal IS the wire value). Writer refuses ordinals > 255; reader rejects ordinals ≥ the known biome count (parse-time validation; the palette's runtime Dirt fallback for in-memory values is unchanged). Length must equal `MapSize²`. |
 | `TOWN` / `0x4E574F54` | `i32 count`, then per town: `f32 X` · `f32 Y` · `u8 tier` · `u8 isHighwayNode` (0/1) | Tier ordinals from `Enums.cs::TownTier`, append-only, range-checked on read. The highway-node flag is what the generator's road topology was built from (v1 dropped it); carried and exposed on the parsed blueprint, consumed by nothing server-side yet. |
-| `TCRV` / `0x56524354` | 50 B: `u16 curveVersion` · input knots `f32 t1..t4` · `f32 spikeMax` · output bands `f32 sea` · `f32 orangeCeil` · `f32 redCeil` · `f32 plateauLo` · `f32 plateauHi` · `f32 peakCap` · `f32 tailSlope` | Optional — present iff the height-redistribution curve shaped this blueprint's `HGTS` (config `TerrainCurve: "v2"`); absent = raw legacy profile. **`spikeMax` semantics by version:** v1 = the pooled calibration max (identical every seed); **v2 = the SEED'S own effective raw pre-curve maximum** — the per-seed spike normalizer, which is why blueprints are no longer reproducible from curve constants alone and the value is recorded here. **Metadata only:** exported heights are already curved; nothing re-applies the map. The curve lives in `Tools/Scripts/HeightCurve.cs` (calibration provenance in its header + the task-05/06 reports). |
+| `TCRV` / `0x56524354` | 50 B: `u16 curveVersion` · `f32 knot1..knot4` · `f32 spikeMax` · `f32 sea` · `f32 orangeCeil` · `f32 redCeil` · `f32 benchLo` · `f32 benchHi` · `f32 peakCap` · `f32 tailSlope` | Optional — present iff the height-redistribution curve shaped this blueprint's `HGTS` (config `TerrainCurve: "v3"`); absent = raw legacy profile. **The `u16 curveVersion` selects the field semantics and the unserialized anchor set:** v1 — knots t1..t4, spikeMax = pooled calibration max, benchLo/Hi = the 50 m plateau's lo/hi. v2 — as v1 but spikeMax = the seed's effective raw pre-curve maximum (per-seed spike normalizer). **v3 (current)** — knots = K1..K4 of six (K5 = 0.930304, K6 = 1.050720 are version constants, not serialized), spikeMax per-seed, **benchLo = the 100 m foothill bench, benchHi = the 220 m white plateau**; bench step (+0.008) and segment shapes are version constants in `HeightCurve.cs`. Because spikeMax is per-seed (v2+), blueprints are not reproducible from curve constants alone — that is why it is recorded. **Metadata only:** exported heights are already curved; nothing re-applies the map. Calibration provenance: `HeightCurve.cs` header + the task-05/06/07 reports. |
 | `WBID` / `0x44494257` | `MapSize²` × `u16` water-body id, same pixel order as `HGTS` | Optional (absent = no water data, e.g. a legacy re-encode). `0` = no water, `1` = **the** ocean body, `2..N` = lakes. Ids assigned in deterministic scan order (X outer / Y inner, first-encountered pixel), lakes labeled with the **same 4-connectivity as `CalculateTrueOcean`**. Membership is exactly the generator's water classification — the biome grid's Ocean/Lake pixels and this grid's nonzero pixels are the same set **by construction** (shared predicates). Length must equal `2·MapSize²`. |
 | `WBTB` / `0x42544257` | `i32 count`, then per body (20 B): `u16 id` · `u8 type` (0 ocean, 1 lake) · `u8 salinity` (0 fresh, 1 salt) · `f32 surfaceLevel` · `i32 pixelCount` · `f32 centroidX` · `f32 centroidY` | Optional, paired with `WBID`. **`surfaceLevel` is a documented TRANSITIONAL rule:** one flat level per body — `GetSeaLevel` at the body's pixel centroid (ocean: at the map centre) under the still-live latitude field; superseded by the flat-scalar sea model (minted, lands with the coast change set). The field's per-pixel slope is deliberately NOT baked into any section. **Salinity is a provisional default** (ocean salt, lake fresh) — a placeholder for the future fresh/salt irrigation mechanic, not a mechanic. |
 | `WSRF` / `0x46525357` | `MapSize²` × `u16` quantized water-surface elevation, same pixel order | Optional, paired with `WBID`. `0` is the reserved **no-water sentinel**; a real level `L` (raw height units) encodes as `1 + round(L × 32768)` so it can never encode to 0; decode `(q − 1)/32768` (`BlueprintFormat.EncodeWaterLevel`/`DecodeWaterLevel`). Covers `[0 … ~1.99997]` raw at `1/32768` raw ≈ **7.7 mm** of world height (1 raw = 251 m) — far finer than the 1 m voxel. Nonzero exactly where `WBID` is nonzero; the value is the pixel's body level. |
@@ -106,12 +106,13 @@ body).
   which model produced it (the `WBTB` levels are the observable).
 - **`SkipRoads`** (bool, default false) — exports with present-but-empty road sections (see the
   road-section table note).
-- **`TerrainCurve`** (`"v2"` | `"off"`, default `"v2"`; `"v1"` retired by the task-06
-  recalibration and rejected loudly) — whether the height-redistribution curve (storm ladder:
-  75 % orange coverage, 50 m plateau, **per-seed-normalized 420 m peaks**) shapes `HGTS`.
-  Biome/water classification is curve-invariant by construction (it classifies the retained
-  uncurved heights); town positions and everything 3D follow the curved terrain. When on,
-  `TCRV` records the effective parameters including the per-seed `spikeMax`.
+- **`TerrainCurve`** (`"v3"` | `"off"`, default `"v3"`; `"v1"`/`"v2"` retired by successor
+  recalibrations and rejected loudly) — whether the height-redistribution curve (the terraced
+  ascent: 59 % orange lowlands, 100 m foothill bench, 220 m white plateau, per-seed-normalized
+  420 m summit spires) shapes `HGTS`. Biome/water classification is curve-invariant by
+  construction (it classifies the retained uncurved heights); town positions and everything 3D
+  follow the curved terrain. When on, `TCRV` records the effective parameters including the
+  per-seed `spikeMax`.
 
 ### Deliberately NOT a section: basins (`BSIN`)
 
diff --git a/Tools/Scripts/README.md b/Tools/Scripts/README.md
index 0fb6401..4ecd533 100644
--- a/Tools/Scripts/README.md
+++ b/Tools/Scripts/README.md
@@ -11,12 +11,13 @@ Generates the entire 2D blueprint. Roughly in order:
 2. **Topography** — FastNoiseLite base height plus a mountain spine, minus a squircle distance
    falloff, giving a guaranteed island. Noise frequency is divided by `scaleFactor`
    (`MapSize / 1024f`) so terrain features stay the same real-world size at any map profile.
-   When `TerrainCurve: "v2"` (the default), the calibrated height-redistribution curve
-   (`HeightCurve.cs` — flat farmable lowlands, 50 m plateau shelf, and a per-seed-normalized
-   spike to the 420 m peak cap: every island's tallest point reaches the ceiling) reshapes
-   above-sea terrain after noise/falloff/Trench and before the crater carve; biome
-   classification reads a retained uncurved map, so biomes are identical either way. Drops the
-   `0_height` hillshade snapshot (hypsometric bands × NW hillshade) in both modes.
+   When `TerrainCurve: "v3"` (the default), the calibrated height-redistribution curve
+   (`HeightCurve.cs` — the terraced ascent: flat farmable lowlands, a walkable 100 m foothill
+   bench, the white mountain-town plateau at 220 m, and a per-seed-normalized summit spike to
+   the 420 m cap: every island's tallest point reaches the ceiling) reshapes above-sea terrain
+   after noise/falloff/Trench and before the crater carve; biome classification reads a
+   retained uncurved map, so biomes are identical either way. Drops the `0_height` hillshade
+   snapshot (hypsometric bands × NW hillshade) in both modes.
 3. **Sea level and water** — sea level per the configured model (`SeaLevelModel`: `"flat"` scalar
    — the default, `SeaLevelValue` 0.15 — or the legacy `"field"` latitude Lerp); flood fill
    separates true ocean from inland lakes; a mainland fill guarantees one contiguous landmass.