diff --git a/.project/designs/app/package.json b/.project/designs/app/package.json
index 45035c21..1b874441 100644
--- a/.project/designs/app/package.json
+++ b/.project/designs/app/package.json
@@ -23,6 +23,7 @@
     "@types/styled-components": "^5.1.34",
     "@vitejs/plugin-react": "^4.4.1",
     "typescript": "^5.8.3",
-    "vite": "^6.3.3"
+    "vite": "^6.3.3",
+    "vite-plugin-wasm": "^3.6.0"
   }
 }
diff --git a/.project/designs/app/src/utils/wasm/useWasmGrid.ts b/.project/designs/app/src/utils/wasm/useWasmGrid.ts
new file mode 100644
index 00000000..8b59f462
--- /dev/null
+++ b/.project/designs/app/src/utils/wasm/useWasmGrid.ts
@@ -0,0 +1,31 @@
+import { useState, useEffect, useRef } from "react";
+import type { WasmGrid } from "../../../../../../.local/build/wasm/magic_civ_physics";
+
+type GridState =
+  | { status: "idle" }
+  | { status: "loading" }
+  | { status: "ready"; grid: WasmGrid }
+  | { status: "error"; message: string };
+
+export function useWasmGrid(seed: number, mapSize: string = "tiny"): GridState {
+  const [state, setState] = useState<GridState>({ status: "idle" });
+  const genRef = useRef(0);
+
+  useEffect(() => {
+    const gen = ++genRef.current;
+    setState({ status: "loading" });
+
+    import("../../../../../../.local/build/wasm/magic_civ_physics")
+      .then(({ WasmGrid }) => {
+        if (gen !== genRef.current) return;
+        const grid = WasmGrid.generateForLab(BigInt(seed), mapSize);
+        setState({ status: "ready", grid });
+      })
+      .catch((err: unknown) => {
+        if (gen !== genRef.current) return;
+        setState({ status: "error", message: String(err) });
+      });
+  }, [seed, mapSize]);
+
+  return state;
+}
diff --git a/.project/designs/app/vite.config.ts b/.project/designs/app/vite.config.ts
index 1bfd1256..27929144 100644
--- a/.project/designs/app/vite.config.ts
+++ b/.project/designs/app/vite.config.ts
@@ -1,9 +1,11 @@
 import path from "path";
 import { defineConfig } from "vite";
 import react from "@vitejs/plugin-react";
+import wasm from "vite-plugin-wasm";
 
 export default defineConfig({
-  plugins: [react()],
+  plugins: [wasm(), react()],
+  build: { target: "esnext" },
   resolve: {
     alias: {
       "@game-data":   path.resolve(__dirname, "../../../public/games/age-of-dwarves/data"),
@@ -26,6 +28,7 @@ export default defineConfig({
         path.resolve(__dirname, "../../../public"),
         path.resolve(__dirname, "../../../.local/audio-alternatives"),
         path.resolve(__dirname, "../../../.local/audio-staging"),
+        path.resolve(__dirname, "../../../.local/build/wasm"),
         path.resolve(__dirname, "../../reports"),
       ],
     },
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index 50991792..97639e0f 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -50,6 +50,9 @@ importers:
       vite:
         specifier: ^6.3.3
         version: 6.4.2(@types/node@25.6.0)(tsx@4.21.0)
+      vite-plugin-wasm:
+        specifier: ^3.6.0
+        version: 3.6.0(vite@6.4.2(@types/node@25.6.0)(tsx@4.21.0))
 
   public/games/age-of-dwarves/guide:
     dependencies:
diff --git a/public/games/age-of-dwarves/data/world_shapes/manifest.json b/public/games/age-of-dwarves/data/world_shapes/manifest.json
new file mode 100644
index 00000000..e74cb5ea
--- /dev/null
+++ b/public/games/age-of-dwarves/data/world_shapes/manifest.json
@@ -0,0 +1,62 @@
+{
+  "schema_version": "1",
+  "default": "earthlike",
+  "earthlike": {
+    "id": "earthlike",
+    "name": "Earthlike",
+    "description": "Familiar continents, moderate climate, balanced rainfall.",
+    "axes": {
+      "landmass": "continents",
+      "climate": "temperate",
+      "moisture": "balanced",
+      "age": "mature",
+      "sea_level": "standard"
+    },
+    "param_overrides": {
+      "plate_count": 10,
+      "convergent_bias": 0.40,
+      "divergent_bias": -0.25,
+      "sea_level": 0.28,
+      "ocean_percentage": { "target": 0.40 },
+      "temp_offset": 0.0,
+      "latitude_gradient": 0.7,
+      "base_precip_offset": 0.0,
+      "windward_boost": 1.5,
+      "leeward_factor": 0.4,
+      "erosion_iterations": 5,
+      "seasonality_scale": 0.8,
+      "rain_shadow_factor": 1.0
+    },
+    "thumbnail": "world_shapes/previews/earthlike.png",
+    "is_default": true
+  },
+  "axes": {
+    "landmass": ["pangaea", "continents", "archipelago", "islands", "shattered"],
+    "climate": ["cold", "temperate", "hot", "extreme"],
+    "moisture": ["arid", "dry", "balanced", "wet", "lush"],
+    "age": ["young", "mature", "ancient"],
+    "sea_level": ["low", "standard", "high"]
+  },
+  "presets": [
+    "landmass/pangaea.json",
+    "landmass/continents.json",
+    "landmass/archipelago.json",
+    "landmass/islands.json",
+    "landmass/shattered.json",
+    "climate/cold.json",
+    "climate/temperate.json",
+    "climate/hot.json",
+    "climate/extreme.json",
+    "moisture/arid.json",
+    "moisture/dry.json",
+    "moisture/balanced.json",
+    "moisture/wet.json",
+    "moisture/lush.json",
+    "age/young.json",
+    "age/mature.json",
+    "age/ancient.json",
+    "sea_level/low.json",
+    "sea_level/standard.json",
+    "sea_level/high.json"
+  ]
+}
diff --git a/src/simulator/api-wasm/src/lib.rs b/src/simulator/api-wasm/src/lib.rs
index 6b50453b..b9dc3b9e 100644
--- a/src/simulator/api-wasm/src/lib.rs
+++ b/src/simulator/api-wasm/src/lib.rs
@@ -1,11 +1,12 @@
 //! WASM API surface — exposes Rust simulation to the web guide via wasm-bindgen.
 //! All public functions match the signatures specified in Task #2.
+//! See: public/games/age-of-dwarves/docs/terrain/WORLDGEN_PIPELINE.md
 
 use wasm_bindgen::prelude::*;
 
 use mc_core::grid::{GridState, biome_registry::{has_tag, BiomeTag}};
 use mc_climate::{ClimatePhysics, EcologyPhysics, step_atmospheric_chemistry};
-use mc_mapgen::MapGenerator;
+use mc_mapgen::{MapGenerator, seed::{derive as derive_seed, SeedDomain}};
 
 /// WASM-exposed grid handle wrapping GridState.
 #[wasm_bindgen]
@@ -36,6 +37,19 @@ impl WasmGrid {
         Ok(Self { inner })
     }
 
+    /// Run the full worldgen pipeline (tectonics → climate → erosion → hydrology)
+    /// and return a populated WasmGrid ready for tile_*_json queries.
+    /// `map_size` accepts "duel" | "tiny" | "small" | "standard" | "large" | "huge".
+    /// Used by the design lab's per-layer playground pages (p1-53).
+    /// See: public/games/age-of-dwarves/docs/terrain/WORLDGEN_PIPELINE.md
+    #[wasm_bindgen(js_name = "generateForLab")]
+    pub fn generate_for_lab(seed: u64, map_size: &str) -> WasmGrid {
+        let gen = MapGenerator::new("{}");
+        WasmGrid {
+            inner: gen.generate(seed, map_size),
+        }
+    }
+
     #[wasm_bindgen(getter)]
     pub fn width(&self) -> i32 {
         self.inner.width
@@ -329,6 +343,25 @@ impl WasmEcologyPhysics {
     }
 }
 
+/// Derive a deterministic sub-seed for the given domain from a map seed.
+/// `domain` matches SeedDomain discriminants: 0=Tectonics, 1=Erosion,
+/// 2=Hydrology, 3=Climate, 4=FloraSelect, 5=FaunaSelect.
+/// Used by the RNG playground page (p1-53).
+/// See: public/games/age-of-dwarves/docs/terrain/WORLDGEN_PIPELINE.md
+#[wasm_bindgen(js_name = "seedDerive")]
+pub fn wasm_seed_derive(map_seed: u64, domain: u8) -> u64 {
+    let d = match domain {
+        0 => SeedDomain::Tectonics,
+        1 => SeedDomain::Erosion,
+        2 => SeedDomain::Hydrology,
+        3 => SeedDomain::Climate,
+        4 => SeedDomain::FloraSelect,
+        5 => SeedDomain::FaunaSelect,
+        _ => SeedDomain::Tectonics,
+    };
+    derive_seed(map_seed, d)
+}
+
 /// WASM-exposed atmospheric chemistry step.
 #[wasm_bindgen(js_name = "stepAtmosphericChemistry")]
 pub fn wasm_step_atmospheric_chemistry(grid: &mut WasmGrid, spec_json: &str) {