diff --git a/src/client/InputHandler.ts b/src/client/InputHandler.ts
index 45d1188a3..6ffc3b161 100644
--- a/src/client/InputHandler.ts
+++ b/src/client/InputHandler.ts
@@ -136,6 +136,10 @@ export class TickMetricsEvent implements GameEvent {
   ) {}
 }
 
+export class WebGPUComputeMetricsEvent implements GameEvent {
+  constructor(public readonly computeMs: number) {}
+}
+
 export class InputHandler {
   private lastPointerX: number = 0;
   private lastPointerY: number = 0;
diff --git a/src/client/UserSettingModal.ts b/src/client/UserSettingModal.ts
index 0ada4565d..4e27a42c3 100644
--- a/src/client/UserSettingModal.ts
+++ b/src/client/UserSettingModal.ts
@@ -371,16 +371,6 @@ export class UserSettingModal extends BaseModal {
     console.log("🏳️ Territory Patterns:", enabled ? "ON" : "OFF");
   }
 
-  private changeTerritoryBorderMode(e: CustomEvent<{ value: string }>) {
-    const value = e.detail?.value;
-    if (typeof value !== "string") return;
-
-    const mode = parseInt(value, 10);
-    if (!Number.isFinite(mode)) return;
-
-    this.userSettings.setInt("settings.territoryBorderMode", mode);
-  }
-
   private togglePerformanceOverlay(e: CustomEvent<{ checked: boolean }>) {
     const enabled = e.detail?.checked;
     if (typeof enabled !== "boolean") return;
@@ -805,21 +795,6 @@ export class UserSettingModal extends BaseModal {
           this.toggleDarkMode(e)}
       ></setting-toggle>
 
-      <setting-select
-        label="${translateText("user_setting.territory_border_mode_label")}"
-        description="${translateText(
-          "user_setting.territory_border_mode_desc",
-        )}"
-        id="territory-border-mode-select"
-        .value=${String(this.userSettings.territoryBorderMode())}
-        .options=${[
-          { value: "0", label: "Off" },
-          { value: "1", label: "Simple" },
-          { value: "2", label: "Glow" },
-        ]}
-        @change=${this.changeTerritoryBorderMode}
-      ></setting-select>
-
       <!-- 😊 Emojis -->
       <setting-toggle
         label="${translateText("user_setting.emojis_label")}"
diff --git a/src/client/graphics/GameRenderer.ts b/src/client/graphics/GameRenderer.ts
index 5c9227ebd..f4b3f0d0d 100644
--- a/src/client/graphics/GameRenderer.ts
+++ b/src/client/graphics/GameRenderer.ts
@@ -41,6 +41,7 @@ import { TerritoryLayer } from "./layers/TerritoryLayer";
 import { UILayer } from "./layers/UILayer";
 import { UnitDisplay } from "./layers/UnitDisplay";
 import { UnitLayer } from "./layers/UnitLayer";
+import { WebGPUDebugOverlay } from "./layers/WebGPUDebugOverlay";
 import { WinModal } from "./layers/WinModal";
 
 export function createRenderer(
@@ -222,6 +223,16 @@ export function createRenderer(
   performanceOverlay.eventBus = eventBus;
   performanceOverlay.userSettings = userSettings;
 
+  const webgpuDebugOverlay = document.querySelector(
+    "webgpu-debug-overlay",
+  ) as WebGPUDebugOverlay;
+  if (!(webgpuDebugOverlay instanceof WebGPUDebugOverlay)) {
+    console.error("webgpu debug overlay not found");
+  }
+  webgpuDebugOverlay.eventBus = eventBus;
+  webgpuDebugOverlay.userSettings = userSettings;
+  webgpuDebugOverlay.requestUpdate();
+
   const alertFrame = document.querySelector("alert-frame") as AlertFrame;
   if (!(alertFrame instanceof AlertFrame)) {
     console.error("alert frame not found");
@@ -288,6 +299,7 @@ export function createRenderer(
     new AdTimer(game),
     alertFrame,
     performanceOverlay,
+    webgpuDebugOverlay,
   ];
 
   return new GameRenderer(
@@ -298,6 +310,7 @@ export function createRenderer(
     uiState,
     layers,
     performanceOverlay,
+    webgpuDebugOverlay,
   );
 }
 
@@ -312,6 +325,7 @@ export class GameRenderer {
     public uiState: UIState,
     private layers: Layer[],
     private performanceOverlay: PerformanceOverlay,
+    private webgpuDebugOverlay: WebGPUDebugOverlay,
   ) {
     // Keep the main canvas transparent; the WebGPU territory canvas renders the background.
     const context = canvas.getContext("2d", { alpha: true });
@@ -401,6 +415,7 @@ export class GameRenderer {
 
     const layerDurations = FrameProfiler.consume();
     this.performanceOverlay.updateFrameMetrics(duration, layerDurations);
+    this.webgpuDebugOverlay.updateFrameMetrics(duration);
 
     if (duration > 50) {
       console.warn(
diff --git a/src/client/graphics/layers/SettingsModal.ts b/src/client/graphics/layers/SettingsModal.ts
index db0cf14b8..a18793a19 100644
--- a/src/client/graphics/layers/SettingsModal.ts
+++ b/src/client/graphics/layers/SettingsModal.ts
@@ -141,16 +141,6 @@ export class SettingsModal extends LitElement implements Layer {
     this.requestUpdate();
   }
 
-  private onTerritoryBorderModeChange(event: Event) {
-    const value = (event.target as HTMLSelectElement).value;
-    const mode = Number.parseInt(value, 10);
-    if (!Number.isFinite(mode))
-      throw new Error(`Invalid border mode: ${value}`);
-
-    this.userSettings.setInt("settings.territoryBorderMode", mode);
-    this.requestUpdate();
-  }
-
   private onToggleRandomNameModeButtonClick() {
     this.userSettings.toggleRandomName();
     this.requestUpdate();
@@ -171,6 +161,11 @@ export class SettingsModal extends LitElement implements Layer {
     this.requestUpdate();
   }
 
+  private onToggleWebgpuDebugOverlayButtonClick() {
+    this.userSettings.toggleWebgpuDebug();
+    this.requestUpdate();
+  }
+
   private onExitButtonClick() {
     // redirect to the home page
     window.location.href = "/";
@@ -296,34 +291,6 @@ export class SettingsModal extends LitElement implements Layer {
               </div>
             </button>
 
-            <div
-              class="flex gap-3 items-center w-full text-left p-3 hover:bg-slate-700 rounded-sm text-white transition-colors"
-            >
-              <img
-                src=${treeIcon}
-                alt="territoryBorderMode"
-                width="20"
-                height="20"
-              />
-              <div class="flex-1">
-                <div class="font-medium">
-                  ${translateText("user_setting.territory_border_mode_label")}
-                </div>
-                <div class="text-sm text-slate-400">
-                  ${translateText("user_setting.territory_border_mode_desc")}
-                </div>
-              </div>
-              <select
-                class="shrink-0 bg-slate-900 border border-slate-600 text-white/90 rounded px-2 py-1 focus:outline-none focus:ring-2 focus:ring-blue-600"
-                .value=${String(this.userSettings.territoryBorderMode())}
-                @change=${this.onTerritoryBorderModeChange}
-              >
-                <option value="0">Off</option>
-                <option value="1">Simple</option>
-                <option value="2">Glow</option>
-              </select>
-            </div>
-
             <button
               class="flex gap-3 items-center w-full text-left p-3 hover:bg-slate-700 rounded-sm text-white transition-colors"
               @click="${this.onToggleEmojisButtonClick}"
@@ -529,6 +496,29 @@ export class SettingsModal extends LitElement implements Layer {
               </div>
             </button>
 
+            <button
+              class="flex gap-3 items-center w-full text-left p-3 hover:bg-slate-700 rounded-sm text-white transition-colors"
+              @click="${this.onToggleWebgpuDebugOverlayButtonClick}"
+            >
+              <img
+                src=${settingsIcon}
+                alt="webgpuDebugIcon"
+                width="20"
+                height="20"
+              />
+              <div class="flex-1">
+                <div class="font-medium">WebGPU Debug</div>
+                <div class="text-sm text-slate-400">
+                  Territory shader selection + options
+                </div>
+              </div>
+              <div class="text-sm text-slate-400">
+                ${this.userSettings.webgpuDebug()
+                  ? translateText("user_setting.on")
+                  : translateText("user_setting.off")}
+              </div>
+            </button>
+
             <div class="border-t border-slate-600 pt-3 mt-4">
               <button
                 class="flex gap-3 items-center w-full text-left p-3 hover:bg-red-600/20 rounded-sm text-red-400 transition-colors"
diff --git a/src/client/graphics/layers/TerritoryLayer.ts b/src/client/graphics/layers/TerritoryLayer.ts
index 2c3159c70..ca84253f0 100644
--- a/src/client/graphics/layers/TerritoryLayer.ts
+++ b/src/client/graphics/layers/TerritoryLayer.ts
@@ -4,9 +4,17 @@ import { UnitType } from "../../../core/game/Game";
 import { TileRef } from "../../../core/game/GameMap";
 import { GameView } from "../../../core/game/GameView";
 import { UserSettings } from "../../../core/game/UserSettings";
-import { AlternateViewEvent, MouseOverEvent } from "../../InputHandler";
+import {
+  AlternateViewEvent,
+  MouseOverEvent,
+  WebGPUComputeMetricsEvent,
+} from "../../InputHandler";
 import { FrameProfiler } from "../FrameProfiler";
 import { TransformHandler } from "../TransformHandler";
+import {
+  buildTerritoryShaderParams,
+  readTerritoryShaderId,
+} from "../webgpu/render/TerritoryShaderRegistry";
 import { TerritoryRenderer } from "../webgpu/TerritoryRenderer";
 import { Layer } from "./Layer";
 
@@ -27,7 +35,7 @@ export class TerritoryLayer implements Layer {
 
   private lastPaletteSignature: string | null = null;
   private lastDefensePostsSignature: string | null = null;
-  private lastBorderMode: number | null = null;
+  private lastTerritoryShaderSignature: string | null = null;
 
   private lastMousePosition: { x: number; y: number } | null = null;
   private hoveredOwnerSmallId: number | null = null;
@@ -69,7 +77,7 @@ export class TerritoryLayer implements Layer {
 
     this.refreshPaletteIfNeeded();
     this.refreshDefensePostsIfNeeded();
-    this.refreshBorderModeIfNeeded();
+    this.applyTerritoryShaderSettings();
 
     const updatedTiles = this.game.recentlyUpdatedTiles();
     for (let i = 0; i < updatedTiles.length; i++) {
@@ -79,7 +87,12 @@ export class TerritoryLayer implements Layer {
     // After collecting pending updates and handling palette/theme changes,
     // invoke the renderer's tick() to process compute passes. This ensures
     // compute shaders run at the simulation rate rather than every frame.
-    this.territoryRenderer?.tick();
+    if (this.territoryRenderer) {
+      const start = performance.now();
+      this.territoryRenderer.tick();
+      const computeMs = performance.now() - start;
+      this.eventBus.emit(new WebGPUComputeMetricsEvent(computeMs));
+    }
 
     FrameProfiler.end("TerritoryLayer:tick", tickProfile);
   }
@@ -100,8 +113,7 @@ export class TerritoryLayer implements Layer {
     this.territoryRenderer = renderer;
     this.territoryRenderer.setAlternativeView(this.alternativeView);
     this.territoryRenderer.setHighlightedOwnerId(this.hoveredOwnerSmallId);
-    this.lastBorderMode = this.userSettings.territoryBorderMode();
-    this.territoryRenderer.setBorderMode(this.lastBorderMode);
+    this.applyTerritoryShaderSettings(true);
     this.territoryRenderer.markAllDirty();
     this.territoryRenderer.refreshPalette();
     this.lastPaletteSignature = this.computePaletteSignature();
@@ -130,7 +142,7 @@ export class TerritoryLayer implements Layer {
     }
 
     // Apply user settings even while the game is paused (settings modal).
-    this.refreshBorderModeIfNeeded();
+    this.applyTerritoryShaderSettings();
 
     this.ensureTerritoryCanvasAttached(context.canvas);
     this.updateHoverHighlight();
@@ -289,15 +301,25 @@ export class TerritoryLayer implements Layer {
     }
   }
 
-  private refreshBorderModeIfNeeded() {
+  private applyTerritoryShaderSettings(force: boolean = false) {
     if (!this.territoryRenderer) {
       return;
     }
-    const mode = this.userSettings.territoryBorderMode();
-    if (mode !== this.lastBorderMode) {
-      this.lastBorderMode = mode;
-      this.territoryRenderer.setBorderMode(mode);
+
+    const shaderId = readTerritoryShaderId(this.userSettings);
+    const { shaderPath, params0, params1 } = buildTerritoryShaderParams(
+      this.userSettings,
+      shaderId,
+    );
+
+    const signature = `${shaderPath}:${Array.from(params0).join(",")}:${Array.from(params1).join(",")}`;
+    if (!force && signature === this.lastTerritoryShaderSignature) {
+      return;
     }
+    this.lastTerritoryShaderSignature = signature;
+
+    this.territoryRenderer.setTerritoryShader(shaderPath);
+    this.territoryRenderer.setTerritoryShaderParams(params0, params1);
   }
 
   private computeDefensePostsSignature(): string {
diff --git a/src/client/graphics/layers/WebGPUDebugOverlay.ts b/src/client/graphics/layers/WebGPUDebugOverlay.ts
new file mode 100644
index 000000000..8d9619ab1
--- /dev/null
+++ b/src/client/graphics/layers/WebGPUDebugOverlay.ts
@@ -0,0 +1,286 @@
+import { css, html, LitElement } from "lit";
+import { customElement, property, state } from "lit/decorators.js";
+import { live } from "lit/directives/live.js";
+import { EventBus } from "../../../core/EventBus";
+import { UserSettings } from "../../../core/game/UserSettings";
+import { WebGPUComputeMetricsEvent } from "../../InputHandler";
+import {
+  TERRITORY_SHADER_KEY,
+  TERRITORY_SHADERS,
+  territoryShaderIdFromInt,
+  territoryShaderIntFromId,
+} from "../webgpu/render/TerritoryShaderRegistry";
+import { Layer } from "./Layer";
+
+@customElement("webgpu-debug-overlay")
+export class WebGPUDebugOverlay extends LitElement implements Layer {
+  @property({ type: Object })
+  public eventBus!: EventBus;
+
+  @property({ type: Object })
+  public userSettings!: UserSettings;
+
+  @state()
+  private renderFps: number = 0;
+
+  @state()
+  private tickComputeMs: number = 0;
+
+  private frameTimes: number[] = [];
+
+  static styles = css`
+    .overlay {
+      position: fixed;
+      top: 16px;
+      left: 16px;
+      z-index: 9999;
+      min-width: 340px;
+      max-width: 420px;
+      background: rgba(0, 0, 0, 0.82);
+      border: 1px solid rgba(255, 255, 255, 0.15);
+      border-radius: 8px;
+      padding: 10px 12px;
+      color: rgba(255, 255, 255, 0.92);
+      font-family:
+        ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas,
+        "Liberation Mono", "Courier New", monospace;
+      font-size: 12px;
+      pointer-events: auto;
+      user-select: none;
+    }
+
+    .title {
+      font-weight: 700;
+      margin-bottom: 8px;
+      display: flex;
+      align-items: center;
+      justify-content: space-between;
+      gap: 8px;
+    }
+
+    .metrics {
+      display: grid;
+      grid-template-columns: 1fr 1fr;
+      gap: 6px 10px;
+      margin-bottom: 10px;
+    }
+
+    .metric {
+      display: flex;
+      justify-content: space-between;
+      gap: 10px;
+      white-space: nowrap;
+    }
+
+    .label {
+      color: rgba(255, 255, 255, 0.7);
+    }
+
+    .value {
+      color: rgba(255, 255, 255, 0.95);
+    }
+
+    .row {
+      display: flex;
+      align-items: center;
+      justify-content: space-between;
+      gap: 10px;
+      margin: 6px 0;
+      user-select: none;
+    }
+
+    select,
+    input[type="range"] {
+      width: 170px;
+    }
+
+    select {
+      background: rgba(0, 0, 0, 0.6);
+      color: rgba(255, 255, 255, 0.92);
+      border: 1px solid rgba(255, 255, 255, 0.2);
+      border-radius: 6px;
+      padding: 4px 6px;
+      font-size: 12px;
+    }
+
+    input[type="checkbox"] {
+      transform: translateY(1px);
+    }
+
+    .range {
+      display: grid;
+      grid-template-columns: 1fr auto;
+      align-items: center;
+      gap: 10px;
+    }
+
+    .rangeValue {
+      min-width: 54px;
+      text-align: right;
+      color: rgba(255, 255, 255, 0.8);
+      font-variant-numeric: tabular-nums;
+    }
+  `;
+
+  init() {
+    this.eventBus.on(WebGPUComputeMetricsEvent, (e) => {
+      if (typeof e.computeMs === "number" && Number.isFinite(e.computeMs)) {
+        this.tickComputeMs = e.computeMs;
+        this.requestUpdate();
+      }
+    });
+    this.requestUpdate();
+  }
+
+  updateFrameMetrics(frameDurationMs: number): void {
+    if (!this.userSettings || !this.userSettings.webgpuDebug()) {
+      return;
+    }
+
+    if (!Number.isFinite(frameDurationMs) || frameDurationMs <= 0) {
+      return;
+    }
+
+    this.frameTimes.push(frameDurationMs);
+    if (this.frameTimes.length > 60) {
+      this.frameTimes.shift();
+    }
+
+    const avgMs =
+      this.frameTimes.reduce((a, b) => a + b, 0) / this.frameTimes.length;
+    this.renderFps = Math.round(1000 / Math.max(1e-6, avgMs));
+    this.requestUpdate();
+  }
+
+  private selectedShaderId() {
+    const selected = this.userSettings.getInt(TERRITORY_SHADER_KEY, 0);
+    return territoryShaderIdFromInt(selected);
+  }
+
+  private setSelectedShaderId(id: "classic" | "retro") {
+    this.userSettings.setInt(
+      TERRITORY_SHADER_KEY,
+      territoryShaderIntFromId(id),
+    );
+    this.requestUpdate();
+  }
+
+  private renderOptionControl(
+    option: (typeof TERRITORY_SHADERS)[number]["options"][number],
+  ) {
+    if (option.kind === "boolean") {
+      const enabled = this.userSettings.get(option.key, option.defaultValue);
+      return html`
+        <div class="row">
+          <div class="label">${option.label}</div>
+          <input
+            type="checkbox"
+            .checked=${live(enabled)}
+            @change=${(e: Event) => {
+              const checked = (e.target as HTMLInputElement).checked;
+              this.userSettings.set(option.key, checked);
+              this.requestUpdate();
+            }}
+          />
+        </div>
+      `;
+    }
+
+    if (option.kind === "enum") {
+      const value = this.userSettings.getInt(option.key, option.defaultValue);
+      return html`
+        <div class="row">
+          <div class="label">${option.label}</div>
+          <select
+            .value=${live(String(value))}
+            @change=${(e: Event) => {
+              const raw = (e.target as HTMLSelectElement).value;
+              const next = Number.parseInt(raw, 10);
+              if (!Number.isFinite(next)) return;
+              this.userSettings.setInt(option.key, next);
+              this.requestUpdate();
+            }}
+          >
+            ${option.options.map(
+              (o) => html`<option value=${String(o.value)}>${o.label}</option>`,
+            )}
+          </select>
+        </div>
+      `;
+    }
+
+    const value = this.userSettings.getFloat(option.key, option.defaultValue);
+    return html`
+      <div class="row">
+        <div class="label">${option.label}</div>
+        <div class="range">
+          <input
+            type="range"
+            min=${String(option.min)}
+            max=${String(option.max)}
+            step=${String(option.step)}
+            .value=${live(String(value))}
+            @input=${(e: Event) => {
+              const raw = (e.target as HTMLInputElement).value;
+              const next = Number.parseFloat(raw);
+              if (!Number.isFinite(next)) return;
+              this.userSettings.setFloat(option.key, next);
+              this.requestUpdate();
+            }}
+          />
+          <div class="rangeValue">${value.toFixed(2)}</div>
+        </div>
+      </div>
+    `;
+  }
+
+  render() {
+    if (!this.userSettings || !this.userSettings.webgpuDebug()) {
+      return null;
+    }
+
+    const shaderId = this.selectedShaderId();
+    const shader =
+      TERRITORY_SHADERS.find((s) => s.id === shaderId) ?? TERRITORY_SHADERS[0];
+
+    return html`
+      <div class="overlay">
+        <div class="title">
+          <div>WebGPU Debug</div>
+        </div>
+
+        <div class="metrics">
+          <div class="metric">
+            <div class="label">tick ms compute</div>
+            <div class="value">${this.tickComputeMs.toFixed(2)}</div>
+          </div>
+          <div class="metric">
+            <div class="label">render fps</div>
+            <div class="value">${this.renderFps}</div>
+          </div>
+        </div>
+
+        <div class="row">
+          <div class="label">Territory Shader</div>
+          <select
+            .value=${live(String(territoryShaderIntFromId(shaderId)))}
+            @change=${(e: Event) => {
+              const raw = (e.target as HTMLSelectElement).value;
+              const next = territoryShaderIdFromInt(Number.parseInt(raw, 10));
+              this.setSelectedShaderId(next);
+            }}
+          >
+            ${TERRITORY_SHADERS.map(
+              (s) =>
+                html`<option value=${String(territoryShaderIntFromId(s.id))}>
+                  ${s.label}
+                </option>`,
+            )}
+          </select>
+        </div>
+
+        ${shader.options.map((opt) => this.renderOptionControl(opt))}
+      </div>
+    `;
+  }
+}
diff --git a/src/client/graphics/webgpu/TerritoryRenderer.ts b/src/client/graphics/webgpu/TerritoryRenderer.ts
index 798682e7a..3cebb41c1 100644
--- a/src/client/graphics/webgpu/TerritoryRenderer.ts
+++ b/src/client/graphics/webgpu/TerritoryRenderer.ts
@@ -28,7 +28,9 @@ export class TerritoryRenderer {
   private resources: GroundTruthData | null = null;
   private ready = false;
   private initPromise: Promise<void> | null = null;
-  private borderMode = 1;
+  private territoryShaderPath = "render/territory.wgsl";
+  private territoryShaderParams0 = new Float32Array(4);
+  private territoryShaderParams1 = new Float32Array(4);
 
   // Compute passes
   private computePasses: ComputePass[] = [];
@@ -99,8 +101,10 @@ export class TerritoryRenderer {
       this.theme,
       state,
     );
-
-    this.resources.setBorderMode(this.borderMode);
+    this.resources.setTerritoryShaderParams(
+      this.territoryShaderParams0,
+      this.territoryShaderParams1,
+    );
 
     // Upload terrain data and params (terrain colors will be computed on GPU)
     this.resources.uploadTerrainData();
@@ -136,6 +140,10 @@ export class TerritoryRenderer {
       );
     }
 
+    if (this.territoryRenderPass) {
+      await this.territoryRenderPass.setShader(this.territoryShaderPath);
+    }
+
     // Compute dependency order (topological sort)
     this.computePassOrder = this.topologicalSort(this.computePasses);
     this.renderPassOrder = this.topologicalSort(this.renderPasses);
@@ -230,12 +238,29 @@ export class TerritoryRenderer {
     this.resources.setHighlightedOwnerId(ownerSmallId);
   }
 
-  setBorderMode(mode: number): void {
-    this.borderMode = mode;
+  setTerritoryShader(shaderPath: string): void {
+    this.territoryShaderPath = shaderPath;
+    if (this.territoryRenderPass) {
+      void this.territoryRenderPass.setShader(shaderPath);
+    }
+  }
+
+  setTerritoryShaderParams(
+    params0: Float32Array | number[],
+    params1: Float32Array | number[],
+  ): void {
+    for (let i = 0; i < 4; i++) {
+      this.territoryShaderParams0[i] = Number(params0[i] ?? 0);
+      this.territoryShaderParams1[i] = Number(params1[i] ?? 0);
+    }
+
     if (!this.resources) {
       return;
     }
-    this.resources.setBorderMode(mode);
+    this.resources.setTerritoryShaderParams(
+      this.territoryShaderParams0,
+      this.territoryShaderParams1,
+    );
   }
 
   markTile(tile: TileRef): void {
@@ -322,6 +347,9 @@ export class TerritoryRenderer {
     // Upload palette if needed
     this.resources.uploadPalette();
 
+    // Upload diplomacy relations (used by retro shader / debug modes)
+    this.resources.uploadRelations();
+
     // Upload defense posts if needed (also produces defended dirty tiles on changes)
     this.resources.uploadDefensePosts();
 
diff --git a/src/client/graphics/webgpu/core/GroundTruthData.ts b/src/client/graphics/webgpu/core/GroundTruthData.ts
index 9bf5a1b73..bef95e294 100644
--- a/src/client/graphics/webgpu/core/GroundTruthData.ts
+++ b/src/client/graphics/webgpu/core/GroundTruthData.ts
@@ -23,6 +23,8 @@ export class GroundTruthData {
   public readonly terrainTexture: GPUTexture;
   public readonly terrainDataTexture: GPUTexture;
   public readonly paletteTexture: GPUTexture;
+  public readonly ownerIndexTexture: GPUTexture;
+  public readonly relationsTexture: GPUTexture;
   public readonly defendedStrengthTexture: GPUTexture;
 
   // Buffers
@@ -65,7 +67,7 @@ export class GroundTruthData {
   private defenseCircleOffsets: Int16Array = new Int16Array(0); // [dx0, dy0, dx1, dy1, ...]
 
   // Uniform data arrays
-  private readonly uniformData = new Float32Array(12);
+  private readonly uniformData = new Float32Array(20);
   private readonly terrainParamsData = new Float32Array(24); // 6 vec4f: shore, water, shorelineWater, plainsBase, highlandBase, mountainBase
   private readonly stateUpdateParamsData = new Uint32Array(4); // updateCount, range, pad, pad
   private readonly defendedStrengthParamsData = new Uint32Array(4); // dirtyCount, range, pad, pad
@@ -78,7 +80,13 @@ export class GroundTruthData {
   private viewOffsetY = 0;
   private alternativeView = false;
   private highlightedOwnerId = -1;
-  private borderMode = 1;
+
+  private territoryShaderParams0 = new Float32Array(4);
+  private territoryShaderParams1 = new Float32Array(4);
+
+  private paletteMaxSmallId = 0;
+  private ownerIndexWidth = 1;
+  private relationsSize = 1;
 
   private constructor(
     private readonly device: GPUDevice,
@@ -102,9 +110,9 @@ export class GroundTruthData {
     const TEXTURE_BINDING = GPUTextureUsage?.TEXTURE_BINDING ?? 0x4;
     const STORAGE_BINDING = GPUTextureUsage?.STORAGE_BINDING ?? 0x8;
 
-    // Render uniforms: 3x vec4f = 48 bytes
+    // Render uniforms: 5x vec4f = 80 bytes
     this.uniformBuffer = device.createBuffer({
-      size: 48,
+      size: 80,
       usage: UNIFORM | COPY_DST_BUF,
     });
 
@@ -140,13 +148,27 @@ export class GroundTruthData {
       usage: TEXTURE_BINDING | STORAGE_BINDING,
     });
 
-    // Palette texture (rgba8unorm)
+    // Palette texture (rgba8unorm): row 0 territory colors, row 1 border colors
     this.paletteTexture = device.createTexture({
-      size: { width: 1, height: 1 },
+      size: { width: 1, height: 2 },
       format: "rgba8unorm",
       usage: COPY_DST_TEX | TEXTURE_BINDING,
     });
 
+    // SmallID -> dense index lookup texture (r32uint)
+    this.ownerIndexTexture = device.createTexture({
+      size: { width: 1, height: 1 },
+      format: "r32uint",
+      usage: COPY_DST_TEX | TEXTURE_BINDING,
+    });
+
+    // Dense relation matrix texture (r8uint)
+    this.relationsTexture = device.createTexture({
+      size: { width: 1, height: 1 },
+      format: "r8uint",
+      usage: COPY_DST_TEX | TEXTURE_BINDING,
+    });
+
     // Terrain texture (rgba8unorm) - output of terrain compute shader
     this.terrainTexture = device.createTexture({
       size: { width: mapWidth, height: mapHeight },
@@ -224,8 +246,14 @@ export class GroundTruthData {
     this.highlightedOwnerId = ownerSmallId ?? -1;
   }
 
-  setBorderMode(mode: number): void {
-    this.borderMode = Math.max(0, Math.min(2, Math.trunc(mode)));
+  setTerritoryShaderParams(
+    params0: Float32Array | number[],
+    params1: Float32Array | number[],
+  ): void {
+    for (let i = 0; i < 4; i++) {
+      this.territoryShaderParams0[i] = Number(params0[i] ?? 0);
+      this.territoryShaderParams1[i] = Number(params1[i] ?? 0);
+    }
   }
 
   // =====================
@@ -447,6 +475,7 @@ export class GroundTruthData {
     for (const player of this.game.playerViews()) {
       maxSmallId = Math.max(maxSmallId, player.smallID());
     }
+    this.paletteMaxSmallId = maxSmallId;
     const nextPaletteWidth =
       GroundTruthData.PALETTE_RESERVED_SLOTS + Math.max(1, maxSmallId + 1);
 
@@ -458,21 +487,23 @@ export class GroundTruthData {
       const COPY_DST_TEX = GPUTextureUsage?.COPY_DST ?? 0x2;
       const TEXTURE_BINDING = GPUTextureUsage?.TEXTURE_BINDING ?? 0x4;
       (this as any).paletteTexture = this.device.createTexture({
-        size: { width: this.paletteWidth, height: 1 },
+        size: { width: this.paletteWidth, height: 2 },
         format: "rgba8unorm",
         usage: COPY_DST_TEX | TEXTURE_BINDING,
       });
       textureRecreated = true;
     }
 
-    const bytes = new Uint8Array(this.paletteWidth * 4);
+    const rowStride = this.paletteWidth * 4;
+    const row0 = new Uint8Array(rowStride);
+    const row1 = new Uint8Array(rowStride);
 
     // Store special colors in reserved slots (0-9)
     const falloutIdx = GroundTruthData.PALETTE_FALLOUT_INDEX * 4;
-    bytes[falloutIdx] = 120;
-    bytes[falloutIdx + 1] = 255;
-    bytes[falloutIdx + 2] = 71;
-    bytes[falloutIdx + 3] = 255;
+    row0[falloutIdx] = 120;
+    row0[falloutIdx + 1] = 255;
+    row0[falloutIdx + 2] = 71;
+    row0[falloutIdx + 3] = 255;
 
     // Store player colors starting at index 10
     for (const player of this.game.playerViews()) {
@@ -480,27 +511,126 @@ export class GroundTruthData {
       if (id <= 0) continue;
       const rgba = player.territoryColor().rgba;
       const idx = (GroundTruthData.PALETTE_RESERVED_SLOTS + id) * 4;
-      bytes[idx] = rgba.r;
-      bytes[idx + 1] = rgba.g;
-      bytes[idx + 2] = rgba.b;
-      bytes[idx + 3] = 255;
+      row0[idx] = rgba.r;
+      row0[idx + 1] = rgba.g;
+      row0[idx + 2] = rgba.b;
+      row0[idx + 3] = 255;
+
+      const borderRgba = player.borderColor().rgba;
+      row1[idx] = borderRgba.r;
+      row1[idx + 1] = borderRgba.g;
+      row1[idx + 2] = borderRgba.b;
+      row1[idx + 3] = 255;
     }
 
-    const bytesPerRow = align(this.paletteWidth * 4, 256);
-    const padded =
-      bytesPerRow === this.paletteWidth * 4
-        ? bytes
-        : (() => {
-            const tmp = new Uint8Array(bytesPerRow);
-            tmp.set(bytes);
-            return tmp;
-          })();
+    const bytesPerRow = align(rowStride, 256);
+    const padded = new Uint8Array(bytesPerRow * 2);
+    padded.set(row0, 0);
+    padded.set(row1, bytesPerRow);
 
     this.device.queue.writeTexture(
       { texture: this.paletteTexture },
       padded,
-      { bytesPerRow, rowsPerImage: 1 },
-      { width: this.paletteWidth, height: 1, depthOrArrayLayers: 1 },
+      { bytesPerRow, rowsPerImage: 2 },
+      { width: this.paletteWidth, height: 2, depthOrArrayLayers: 1 },
+    );
+
+    return textureRecreated;
+  }
+
+  uploadRelations(): boolean {
+    const players = this.game
+      .playerViews()
+      .filter((p) => p.smallID() > 0)
+      .slice()
+      .sort((a, b) => a.smallID() - b.smallID());
+
+    const maxSmallId = this.paletteMaxSmallId;
+    const nextOwnerIndexWidth = Math.max(1, maxSmallId + 1);
+
+    let textureRecreated = false;
+
+    if (nextOwnerIndexWidth !== this.ownerIndexWidth) {
+      this.ownerIndexWidth = nextOwnerIndexWidth;
+      (this.ownerIndexTexture as any).destroy?.();
+      const GPUTextureUsage = (globalThis as any).GPUTextureUsage;
+      const COPY_DST_TEX = GPUTextureUsage?.COPY_DST ?? 0x2;
+      const TEXTURE_BINDING = GPUTextureUsage?.TEXTURE_BINDING ?? 0x4;
+      (this as any).ownerIndexTexture = this.device.createTexture({
+        size: { width: this.ownerIndexWidth, height: 1 },
+        format: "r32uint",
+        usage: COPY_DST_TEX | TEXTURE_BINDING,
+      });
+      textureRecreated = true;
+    }
+
+    const denseBySmallId = new Uint32Array(this.ownerIndexWidth);
+    let dense = 0;
+    for (const p of players) {
+      const id = p.smallID();
+      if (id <= 0 || id >= this.ownerIndexWidth) continue;
+      dense++;
+      denseBySmallId[id] = dense;
+    }
+
+    const ownerIndexBytesPerRow = align(this.ownerIndexWidth * 4, 256);
+    const ownerIndexPaddedU32 = new Uint32Array(ownerIndexBytesPerRow / 4);
+    ownerIndexPaddedU32.set(denseBySmallId);
+    this.device.queue.writeTexture(
+      { texture: this.ownerIndexTexture },
+      ownerIndexPaddedU32,
+      { bytesPerRow: ownerIndexBytesPerRow, rowsPerImage: 1 },
+      { width: this.ownerIndexWidth, height: 1, depthOrArrayLayers: 1 },
+    );
+
+    const nextRelationsSize = Math.max(1, dense + 1);
+    if (nextRelationsSize !== this.relationsSize) {
+      this.relationsSize = nextRelationsSize;
+      (this.relationsTexture as any).destroy?.();
+      const GPUTextureUsage = (globalThis as any).GPUTextureUsage;
+      const COPY_DST_TEX = GPUTextureUsage?.COPY_DST ?? 0x2;
+      const TEXTURE_BINDING = GPUTextureUsage?.TEXTURE_BINDING ?? 0x4;
+      (this as any).relationsTexture = this.device.createTexture({
+        size: { width: this.relationsSize, height: this.relationsSize },
+        format: "r8uint",
+        usage: COPY_DST_TEX | TEXTURE_BINDING,
+      });
+      textureRecreated = true;
+    }
+
+    const relBytesPerRow = align(this.relationsSize, 256);
+    const relPadded = new Uint8Array(relBytesPerRow * this.relationsSize);
+
+    // 0 = neutral, 1 = friendly, 2 = embargo
+    for (let i = 0; i < players.length; i++) {
+      for (let j = i + 1; j < players.length; j++) {
+        const a = players[i];
+        const b = players[j];
+        const aDense = denseBySmallId[a.smallID()];
+        const bDense = denseBySmallId[b.smallID()];
+        if (aDense === 0 || bDense === 0) continue;
+
+        let code = 0;
+        if (a.hasEmbargo(b)) {
+          code = 2;
+        } else if (a.isFriendly(b) || b.isFriendly(a)) {
+          code = 1;
+        }
+
+        relPadded[aDense + bDense * relBytesPerRow] = code;
+        relPadded[bDense + aDense * relBytesPerRow] = code;
+      }
+    }
+
+    this.device.queue.writeTexture(
+      { texture: this.relationsTexture },
+      relPadded,
+      { bytesPerRow: relBytesPerRow, rowsPerImage: this.relationsSize },
+      {
+        width: this.relationsSize,
+        height: this.relationsSize,
+        depthOrArrayLayers: 1,
+      },
     );
 
     return textureRecreated;
@@ -853,9 +983,19 @@ export class GroundTruthData {
     this.uniformData[7] = this.highlightedOwnerId;
     this.uniformData[8] = this.viewWidth;
     this.uniformData[9] = this.viewHeight;
-    this.uniformData[10] = this.borderMode;
+    this.uniformData[10] = this.game.myPlayer()?.smallID() ?? 0;
     this.uniformData[11] = 0;
 
+    this.uniformData[12] = this.territoryShaderParams0[0];
+    this.uniformData[13] = this.territoryShaderParams0[1];
+    this.uniformData[14] = this.territoryShaderParams0[2];
+    this.uniformData[15] = this.territoryShaderParams0[3];
+
+    this.uniformData[16] = this.territoryShaderParams1[0];
+    this.uniformData[17] = this.territoryShaderParams1[1];
+    this.uniformData[18] = this.territoryShaderParams1[2];
+    this.uniformData[19] = this.territoryShaderParams1[3];
+
     this.device.queue.writeBuffer(this.uniformBuffer, 0, this.uniformData);
   }
 
diff --git a/src/client/graphics/webgpu/render/TerritoryRenderPass.ts b/src/client/graphics/webgpu/render/TerritoryRenderPass.ts
index b5d30bc86..34f5f278a 100644
--- a/src/client/graphics/webgpu/render/TerritoryRenderPass.ts
+++ b/src/client/graphics/webgpu/render/TerritoryRenderPass.ts
@@ -16,6 +16,7 @@ export class TerritoryRenderPass implements RenderPass {
   private device: GPUDevice | null = null;
   private resources: GroundTruthData | null = null;
   private canvasFormat: GPUTextureFormat | null = null;
+  private shaderPath = "render/territory.wgsl";
   private clearR = 0;
   private clearG = 0;
   private clearB = 0;
@@ -29,9 +30,6 @@ export class TerritoryRenderPass implements RenderPass {
     this.resources = resources;
     this.canvasFormat = canvasFormat;
 
-    const shaderCode = await loadShader("render/territory.wgsl");
-    const shaderModule = device.createShaderModule({ code: shaderCode });
-
     this.bindGroupLayout = device.createBindGroupLayout({
       entries: [
         {
@@ -59,21 +57,20 @@ export class TerritoryRenderPass implements RenderPass {
           visibility: 2 /* FRAGMENT */,
           texture: { sampleType: "float" },
         },
+        {
+          binding: 5,
+          visibility: 2 /* FRAGMENT */,
+          texture: { sampleType: "uint" },
+        },
+        {
+          binding: 6,
+          visibility: 2 /* FRAGMENT */,
+          texture: { sampleType: "uint" },
+        },
       ],
     });
 
-    this.pipeline = device.createRenderPipeline({
-      layout: device.createPipelineLayout({
-        bindGroupLayouts: [this.bindGroupLayout],
-      }),
-      vertex: { module: shaderModule, entryPoint: "vsMain" },
-      fragment: {
-        module: shaderModule,
-        entryPoint: "fsMain",
-        targets: [{ format: canvasFormat }],
-      },
-      primitive: { topology: "triangle-list" },
-    });
+    await this.setShader(this.shaderPath);
 
     this.rebuildBindGroup();
 
@@ -84,6 +81,30 @@ export class TerritoryRenderPass implements RenderPass {
     this.clearB = bg.b / 255;
   }
 
+  async setShader(shaderPath: string): Promise<void> {
+    this.shaderPath = shaderPath;
+
+    if (!this.device || !this.bindGroupLayout || !this.canvasFormat) {
+      return;
+    }
+
+    const shaderCode = await loadShader(shaderPath);
+    const shaderModule = this.device.createShaderModule({ code: shaderCode });
+
+    this.pipeline = this.device.createRenderPipeline({
+      layout: this.device.createPipelineLayout({
+        bindGroupLayouts: [this.bindGroupLayout],
+      }),
+      vertex: { module: shaderModule, entryPoint: "vsMain" },
+      fragment: {
+        module: shaderModule,
+        entryPoint: "fsMain",
+        targets: [{ format: this.canvasFormat }],
+      },
+      primitive: { topology: "triangle-list" },
+    });
+  }
+
   needsUpdate(): boolean {
     // Always run every frame (can be optimized later if needed)
     return true;
@@ -139,7 +160,9 @@ export class TerritoryRenderPass implements RenderPass {
       !this.resources.stateTexture ||
       !this.resources.defendedStrengthTexture ||
       !this.resources.paletteTexture ||
-      !this.resources.terrainTexture
+      !this.resources.terrainTexture ||
+      !this.resources.ownerIndexTexture ||
+      !this.resources.relationsTexture
     ) {
       return;
     }
@@ -164,6 +187,14 @@ export class TerritoryRenderPass implements RenderPass {
           binding: 4,
           resource: this.resources.terrainTexture.createView(),
         },
+        {
+          binding: 5,
+          resource: this.resources.ownerIndexTexture.createView(),
+        },
+        {
+          binding: 6,
+          resource: this.resources.relationsTexture.createView(),
+        },
       ],
     });
   }
diff --git a/src/client/graphics/webgpu/render/TerritoryShaderRegistry.ts b/src/client/graphics/webgpu/render/TerritoryShaderRegistry.ts
new file mode 100644
index 000000000..183993fa2
--- /dev/null
+++ b/src/client/graphics/webgpu/render/TerritoryShaderRegistry.ts
@@ -0,0 +1,353 @@
+export type TerritoryShaderId = "classic" | "retro";
+
+export type TerritoryShaderOption =
+  | {
+      kind: "boolean";
+      key: string;
+      label: string;
+      defaultValue: boolean;
+    }
+  | {
+      kind: "range";
+      key: string;
+      label: string;
+      defaultValue: number;
+      min: number;
+      max: number;
+      step: number;
+    }
+  | {
+      kind: "enum";
+      key: string;
+      label: string;
+      defaultValue: number;
+      options: Array<{ value: number; label: string }>;
+    };
+
+export interface TerritoryShaderDefinition {
+  id: TerritoryShaderId;
+  label: string;
+  wgslPath: string;
+  options: TerritoryShaderOption[];
+}
+
+export const TERRITORY_SHADER_KEY = "settings.webgpu.territory.shader";
+
+export const TERRITORY_SHADERS: TerritoryShaderDefinition[] = [
+  {
+    id: "classic",
+    label: "Simple",
+    wgslPath: "render/territory.wgsl",
+    options: [
+      {
+        kind: "enum",
+        key: "settings.webgpu.territory.classic.borderMode",
+        label: "Border Mode",
+        defaultValue: 1,
+        options: [
+          { value: 0, label: "Off" },
+          { value: 1, label: "Simple" },
+          { value: 2, label: "Glow" },
+        ],
+      },
+      {
+        kind: "range",
+        key: "settings.webgpu.territory.classic.thicknessPx",
+        label: "Thickness (px)",
+        defaultValue: 1,
+        min: 0.5,
+        max: 8,
+        step: 0.5,
+      },
+      {
+        kind: "range",
+        key: "settings.webgpu.territory.classic.borderStrength",
+        label: "Border Strength",
+        defaultValue: 0.64,
+        min: 0,
+        max: 1,
+        step: 0.01,
+      },
+      {
+        kind: "range",
+        key: "settings.webgpu.territory.classic.glowStrength",
+        label: "Glow Strength",
+        defaultValue: 0.42,
+        min: 0,
+        max: 1,
+        step: 0.01,
+      },
+      {
+        kind: "range",
+        key: "settings.webgpu.territory.classic.glowRadiusMul",
+        label: "Glow Radius",
+        defaultValue: 1,
+        min: 1,
+        max: 12,
+        step: 0.25,
+      },
+      {
+        kind: "boolean",
+        key: "settings.webgpu.territory.classic.drawDefendedRadius",
+        label: "Draw Defended Radius",
+        defaultValue: false,
+      },
+      {
+        kind: "boolean",
+        key: "settings.webgpu.territory.classic.disableDefendedTint",
+        label: "Disable Defended Tint",
+        defaultValue: false,
+      },
+    ],
+  },
+  {
+    id: "retro",
+    label: "Retro",
+    wgslPath: "render/retro.wgsl",
+    options: [
+      {
+        kind: "boolean",
+        key: "settings.webgpu.territory.retro.colorByRelations",
+        label: "Color By Player Relations",
+        defaultValue: true,
+      },
+      {
+        kind: "boolean",
+        key: "settings.webgpu.territory.retro.patternWhenDefended",
+        label: "Pattern When In Defended Range",
+        defaultValue: true,
+      },
+      {
+        kind: "boolean",
+        key: "settings.webgpu.territory.retro.splitBorder",
+        label: "Split Border",
+        defaultValue: true,
+      },
+      {
+        kind: "boolean",
+        key: "settings.webgpu.territory.retro.drawDefendedRadius",
+        label: "Draw Defended Radius",
+        defaultValue: true,
+      },
+      {
+        kind: "boolean",
+        key: "settings.webgpu.territory.retro.disableDefendedTint",
+        label: "Disable Defended Tint",
+        defaultValue: true,
+      },
+      {
+        kind: "range",
+        key: "settings.webgpu.territory.retro.thicknessPx",
+        label: "Thickness (px)",
+        defaultValue: 6,
+        min: 0.5,
+        max: 12,
+        step: 0.5,
+      },
+      {
+        kind: "range",
+        key: "settings.webgpu.territory.retro.borderStrength",
+        label: "Border Strength",
+        defaultValue: 1,
+        min: 0,
+        max: 1,
+        step: 0.01,
+      },
+      {
+        kind: "range",
+        key: "settings.webgpu.territory.retro.glowStrength",
+        label: "Glow Strength",
+        defaultValue: 0,
+        min: 0,
+        max: 1,
+        step: 0.01,
+      },
+      {
+        kind: "range",
+        key: "settings.webgpu.territory.retro.glowRadiusMul",
+        label: "Glow Radius",
+        defaultValue: 1,
+        min: 1,
+        max: 16,
+        step: 0.25,
+      },
+      {
+        kind: "range",
+        key: "settings.webgpu.territory.retro.relationTintStrength",
+        label: "Relation Tint Strength",
+        defaultValue: 1,
+        min: 0,
+        max: 1,
+        step: 0.01,
+      },
+      {
+        kind: "range",
+        key: "settings.webgpu.territory.retro.defendedPatternStrength",
+        label: "Defended Pattern Strength",
+        defaultValue: 0.5,
+        min: 0,
+        max: 1,
+        step: 0.01,
+      },
+      {
+        kind: "range",
+        key: "settings.webgpu.territory.retro.defendedThreshold",
+        label: "Defended Threshold",
+        defaultValue: 0.01,
+        min: 0,
+        max: 1,
+        step: 0.01,
+      },
+    ],
+  },
+];
+
+export function getTerritoryShaderById(
+  id: TerritoryShaderId,
+): TerritoryShaderDefinition {
+  const found = TERRITORY_SHADERS.find((s) => s.id === id);
+  if (!found) {
+    throw new Error(`Unknown territory shader: ${id}`);
+  }
+  return found;
+}
+
+export function territoryShaderIdFromInt(value: number): TerritoryShaderId {
+  return value === 1 ? "retro" : "classic";
+}
+
+export function territoryShaderIntFromId(id: TerritoryShaderId): number {
+  return id === "retro" ? 1 : 0;
+}
+
+export function readTerritoryShaderId(userSettings: {
+  getInt: (key: string, defaultValue: number) => number;
+}): TerritoryShaderId {
+  return territoryShaderIdFromInt(userSettings.getInt(TERRITORY_SHADER_KEY, 0));
+}
+
+export function buildTerritoryShaderParams(
+  userSettings: {
+    get: (key: string, defaultValue: boolean) => boolean;
+    getFloat: (key: string, defaultValue: number) => number;
+    getInt: (key: string, defaultValue: number) => number;
+  },
+  shaderId: TerritoryShaderId,
+): { shaderPath: string; params0: Float32Array; params1: Float32Array } {
+  if (shaderId === "retro") {
+    const thicknessPx = userSettings.getFloat(
+      "settings.webgpu.territory.retro.thicknessPx",
+      6,
+    );
+    const borderStrength = userSettings.getFloat(
+      "settings.webgpu.territory.retro.borderStrength",
+      1,
+    );
+    const glowStrength = userSettings.getFloat(
+      "settings.webgpu.territory.retro.glowStrength",
+      0,
+    );
+    const glowRadiusMul = userSettings.getFloat(
+      "settings.webgpu.territory.retro.glowRadiusMul",
+      1,
+    );
+
+    const colorByRelations = userSettings.get(
+      "settings.webgpu.territory.retro.colorByRelations",
+      true,
+    );
+    const patternWhenDefended = userSettings.get(
+      "settings.webgpu.territory.retro.patternWhenDefended",
+      true,
+    );
+    const splitBorder = userSettings.get(
+      "settings.webgpu.territory.retro.splitBorder",
+      true,
+    );
+    const drawDefendedRadius = userSettings.get(
+      "settings.webgpu.territory.retro.drawDefendedRadius",
+      true,
+    );
+    const disableDefendedTint = userSettings.get(
+      "settings.webgpu.territory.retro.disableDefendedTint",
+      true,
+    );
+    const relationTintStrength = userSettings.getFloat(
+      "settings.webgpu.territory.retro.relationTintStrength",
+      1,
+    );
+    const defendedPatternStrength = userSettings.getFloat(
+      "settings.webgpu.territory.retro.defendedPatternStrength",
+      0.5,
+    );
+    const defendedThreshold = userSettings.getFloat(
+      "settings.webgpu.territory.retro.defendedThreshold",
+      0.01,
+    );
+
+    let flags = 0;
+    if (colorByRelations) flags |= 1 << 0;
+    if (patternWhenDefended) flags |= 1 << 1;
+    if (splitBorder) flags |= 1 << 2;
+    if (drawDefendedRadius) flags |= 1 << 3;
+    if (disableDefendedTint) flags |= 1 << 4;
+
+    const params0 = new Float32Array([
+      thicknessPx,
+      borderStrength,
+      glowStrength,
+      glowRadiusMul,
+    ]);
+    const params1 = new Float32Array([
+      flags,
+      relationTintStrength,
+      defendedPatternStrength,
+      defendedThreshold,
+    ]);
+
+    return { shaderPath: "render/retro.wgsl", params0, params1 };
+  }
+
+  const borderMode = userSettings.getInt(
+    "settings.webgpu.territory.classic.borderMode",
+    1,
+  );
+  const thicknessPx = userSettings.getFloat(
+    "settings.webgpu.territory.classic.thicknessPx",
+    1,
+  );
+  const borderStrength = userSettings.getFloat(
+    "settings.webgpu.territory.classic.borderStrength",
+    0.64,
+  );
+  const glowStrength = userSettings.getFloat(
+    "settings.webgpu.territory.classic.glowStrength",
+    0.42,
+  );
+  const glowRadiusMul = userSettings.getFloat(
+    "settings.webgpu.territory.classic.glowRadiusMul",
+    1,
+  );
+  const drawDefendedRadius = userSettings.get(
+    "settings.webgpu.territory.classic.drawDefendedRadius",
+    false,
+  );
+  const disableDefendedTint = userSettings.get(
+    "settings.webgpu.territory.classic.disableDefendedTint",
+    false,
+  );
+
+  const params0 = new Float32Array([
+    borderMode,
+    thicknessPx,
+    borderStrength,
+    glowStrength,
+  ]);
+  const params1 = new Float32Array([
+    glowRadiusMul,
+    drawDefendedRadius ? 1 : 0,
+    disableDefendedTint ? 1 : 0,
+    0,
+  ]);
+  return { shaderPath: "render/territory.wgsl", params0, params1 };
+}
diff --git a/src/client/graphics/webgpu/shaders/render/retro.wgsl b/src/client/graphics/webgpu/shaders/render/retro.wgsl
new file mode 100644
index 000000000..ad257d504
--- /dev/null
+++ b/src/client/graphics/webgpu/shaders/render/retro.wgsl
@@ -0,0 +1,303 @@
+struct Uniforms {
+  mapResolution_viewScale_time: vec4f, // x=mapW, y=mapH, z=viewScale, w=timeSec
+  viewOffset_alt_highlight: vec4f,     // x=offX, y=offY, z=alternativeView, w=highlightOwnerId
+  viewSize_pad: vec4f,                // x=viewW, y=viewH, z=myPlayerSmallId, w unused
+  shaderParams0: vec4f,               // x=thicknessPx, y=borderStrength, z=glowStrength, w=glowRadiusMul
+  shaderParams1: vec4f,               // x=flags, y=relationTintStrength, z=defendedPatternStrength, w=defendedThreshold
+};
+
+@group(0) @binding(0) var<uniform> u: Uniforms;
+@group(0) @binding(1) var stateTex: texture_2d<u32>;
+@group(0) @binding(2) var defendedStrengthTex: texture_2d<f32>;
+@group(0) @binding(3) var paletteTex: texture_2d<f32>;
+@group(0) @binding(4) var terrainTex: texture_2d<f32>;
+@group(0) @binding(5) var ownerIndexTex: texture_2d<u32>;
+@group(0) @binding(6) var relationsTex: texture_2d<u32>;
+
+@vertex
+fn vsMain(@builtin(vertex_index) vi: u32) -> @builtin(position) vec4f {
+  var pos = array<vec2f, 3>(
+    vec2f(-1.0, -1.0),
+    vec2f(3.0, -1.0),
+    vec2f(-1.0, 3.0),
+  );
+  let p = pos[vi];
+  return vec4f(p, 0.0, 1.0);
+}
+
+fn hasFlag(flags: u32, bit: u32) -> bool {
+  return (flags & (1u << bit)) != 0u;
+}
+
+fn relationCode(ownerA: u32, ownerB: u32) -> u32 {
+  if (ownerA == 0u || ownerB == 0u) {
+    return 0u;
+  }
+  let aDense = textureLoad(ownerIndexTex, vec2i(i32(ownerA), 0), 0).x;
+  let bDense = textureLoad(ownerIndexTex, vec2i(i32(ownerB), 0), 0).x;
+  if (aDense == 0u || bDense == 0u) {
+    return 0u;
+  }
+  return textureLoad(relationsTex, vec2i(i32(aDense), i32(bDense)), 0).x;
+}
+
+fn applyDefendedPattern(
+  baseRgb: vec3f,
+  strength: f32,
+  texCoord: vec2i,
+) -> vec3f {
+  let parity = (u32(texCoord.x) ^ u32(texCoord.y)) & 1u;
+  let factor = select(0.75, 1.25, parity == 1u);
+  let patterned = clamp(baseRgb * factor, vec3f(0.0), vec3f(1.0));
+  return mix(baseRgb, patterned, clamp(strength, 0.0, 1.0));
+}
+
+@fragment
+fn fsMain(@builtin(position) pos: vec4f) -> @location(0) vec4f {
+  let mapRes = u.mapResolution_viewScale_time.xy;
+  let viewScale = u.mapResolution_viewScale_time.z;
+  let timeSec = u.mapResolution_viewScale_time.w;
+  let viewOffset = u.viewOffset_alt_highlight.xy;
+  let altView = u.viewOffset_alt_highlight.z;
+  let highlightId = u.viewOffset_alt_highlight.w;
+  let myPlayerSmallId = u.viewSize_pad.z;
+
+  let thicknessPx = u.shaderParams0.x;
+  let borderStrength = u.shaderParams0.y;
+  let glowStrength = u.shaderParams0.z;
+  let glowRadiusMul = u.shaderParams0.w;
+
+  let flags = u32(max(0.0, u.shaderParams1.x) + 0.5);
+  let relationTintStrength = u.shaderParams1.y;
+  let defendedPatternStrength = u.shaderParams1.z;
+  let defendedThreshold = u.shaderParams1.w;
+
+  let enableRelations = hasFlag(flags, 0u);
+  let enableDefendedPattern = hasFlag(flags, 1u);
+  let enableSplit = hasFlag(flags, 2u);
+  let drawDefendedRadius = hasFlag(flags, 3u);
+  let disableDefendedTint = hasFlag(flags, 4u);
+
+  // WebGPU fragment position is top-left origin and at pixel centers (0.5, 1.5, ...).
+  let viewCoord = vec2f(pos.x - 0.5, pos.y - 0.5);
+  let mapHalf = mapRes * 0.5;
+  let mapCoord = (viewCoord - mapHalf) / viewScale + viewOffset + mapHalf;
+
+  if (
+    mapCoord.x < 0.0 ||
+    mapCoord.y < 0.0 ||
+    mapCoord.x >= mapRes.x ||
+    mapCoord.y >= mapRes.y
+  ) {
+    discard;
+  }
+
+  let texCoord = vec2i(mapCoord);
+  let state = textureLoad(stateTex, texCoord, 0).x;
+  let owner = state & 0xFFFu;
+  let hasFallout = (state & 0x2000u) != 0u;
+
+  let terrain = textureLoad(terrainTex, texCoord, 0);
+  let defendedStrength = textureLoad(defendedStrengthTex, texCoord, 0).x;
+
+  var outColor = terrain;
+  if (owner != 0u) {
+    // Player colors start at index 10
+    let c = textureLoad(paletteTex, vec2i(i32(owner) + 10, 0), 0);
+    var territoryRgb = c.rgb;
+    if (!disableDefendedTint) {
+      let defendedTint = select(
+        0.0,
+        clamp(0.8 * defendedStrength, 0.1, 0.35),
+        defendedStrength > 0.001,
+      );
+      territoryRgb = mix(
+        territoryRgb,
+        vec3f(1.0, 0.0, 1.0),
+        defendedTint,
+      );
+    }
+    if (hasFallout) {
+      // Fallout color is at index 0
+      let falloutColor = textureLoad(paletteTex, vec2i(0, 0), 0).rgb;
+      territoryRgb = mix(territoryRgb, falloutColor, 0.5);
+    }
+    outColor = vec4f(mix(terrain.rgb, territoryRgb, 0.65), 1.0);
+  } else if (hasFallout) {
+    let falloutColor = textureLoad(paletteTex, vec2i(0, 0), 0).rgb;
+    outColor = vec4f(mix(terrain.rgb, falloutColor, 0.5), 1.0);
+  }
+
+  // In alt view we show only borders on top of terrain.
+  if (altView > 0.5) {
+    outColor = terrain;
+  }
+
+  if (owner != 0u) {
+    let fx = fract(mapCoord.x);
+    let fy = fract(mapCoord.y);
+
+    var bestDist = 1e9;
+    var otherOwner = 0u;
+    var otherCoord = texCoord;
+
+    // Only border against other non-zero owners.
+    if (texCoord.x > 0) {
+      let o = textureLoad(stateTex, texCoord + vec2i(-1, 0), 0).x & 0xFFFu;
+      if (o != 0u && o != owner) {
+        let d = fx;
+        if (d < bestDist) {
+          bestDist = d;
+          otherOwner = o;
+          otherCoord = texCoord + vec2i(-1, 0);
+        }
+      }
+    }
+    if (texCoord.x + 1 < i32(mapRes.x)) {
+      let o = textureLoad(stateTex, texCoord + vec2i(1, 0), 0).x & 0xFFFu;
+      if (o != 0u && o != owner) {
+        let d = 1.0 - fx;
+        if (d < bestDist) {
+          bestDist = d;
+          otherOwner = o;
+          otherCoord = texCoord + vec2i(1, 0);
+        }
+      }
+    }
+    if (texCoord.y > 0) {
+      let o = textureLoad(stateTex, texCoord + vec2i(0, -1), 0).x & 0xFFFu;
+      if (o != 0u && o != owner) {
+        let d = fy;
+        if (d < bestDist) {
+          bestDist = d;
+          otherOwner = o;
+          otherCoord = texCoord + vec2i(0, -1);
+        }
+      }
+    }
+    if (texCoord.y + 1 < i32(mapRes.y)) {
+      let o = textureLoad(stateTex, texCoord + vec2i(0, 1), 0).x & 0xFFFu;
+      if (o != 0u && o != owner) {
+        let d = 1.0 - fy;
+        if (d < bestDist) {
+          bestDist = d;
+          otherOwner = o;
+          otherCoord = texCoord + vec2i(0, 1);
+        }
+      }
+    }
+
+    if (otherOwner != 0u) {
+      let pxPerTile = max(viewScale, 0.001);
+      let aaTiles = 1.0 / pxPerTile;
+      let thicknessTiles = max(0.1, thicknessPx) / pxPerTile;
+
+      let line = 1.0 - smoothstep(thicknessTiles, thicknessTiles + aaTiles, bestDist);
+      let glowTiles = (max(0.1, thicknessPx) * max(0.1, glowRadiusMul)) / pxPerTile;
+      let glow = 1.0 - smoothstep(glowTiles, glowTiles + aaTiles * 3.0, bestDist);
+
+      var baseBorderRgb = textureLoad(paletteTex, vec2i(i32(owner) + 10, 1), 0).rgb;
+
+      if (!enableSplit) {
+        let otherBorderRgb = textureLoad(paletteTex, vec2i(i32(otherOwner) + 10, 1), 0).rgb;
+        baseBorderRgb = 0.5 * (baseBorderRgb + otherBorderRgb);
+      }
+
+      var edgeDefendedStrength = defendedStrength;
+      if (!enableSplit) {
+        let otherDef = textureLoad(defendedStrengthTex, otherCoord, 0).x;
+        edgeDefendedStrength = max(edgeDefendedStrength, otherDef);
+      }
+
+      // Determine relation color (normal: between owners, altView: relation to viewer).
+      var rel = 0u;
+      if (enableRelations) {
+        if (altView > 0.5) {
+          rel = relationCode(owner, u32(max(0.0, myPlayerSmallId) + 0.5));
+        } else {
+          rel = relationCode(owner, otherOwner);
+        }
+      }
+
+      var borderRgb = baseBorderRgb;
+      if (rel != 0u) {
+        let tintTarget = select(vec3f(0.0, 1.0, 0.0), vec3f(1.0, 0.0, 0.0), rel == 2u);
+        let tint = clamp(0.35 * relationTintStrength, 0.0, 1.0);
+        borderRgb = mix(borderRgb, tintTarget, tint);
+      }
+
+      if (enableDefendedPattern && edgeDefendedStrength >= defendedThreshold) {
+        borderRgb = applyDefendedPattern(borderRgb, defendedPatternStrength, texCoord);
+      }
+
+      outColor = vec4f(
+        mix(outColor.rgb, borderRgb, clamp(line * borderStrength, 0.0, 1.0)),
+        outColor.a,
+      );
+      outColor = vec4f(
+        mix(outColor.rgb, borderRgb, clamp(glow * glowStrength, 0.0, 1.0)),
+        outColor.a,
+      );
+    }
+  }
+
+  if (drawDefendedRadius && defendedStrength > 0.001 && owner != 0u) {
+    let fx = fract(mapCoord.x);
+    let fy = fract(mapCoord.y);
+
+    var dist = 1e9;
+
+    if (texCoord.x > 0) {
+      let s = textureLoad(defendedStrengthTex, texCoord + vec2i(-1, 0), 0).x;
+      if (s <= 0.001) {
+        dist = min(dist, fx);
+      }
+    }
+    if (texCoord.x + 1 < i32(mapRes.x)) {
+      let s = textureLoad(defendedStrengthTex, texCoord + vec2i(1, 0), 0).x;
+      if (s <= 0.001) {
+        dist = min(dist, 1.0 - fx);
+      }
+    }
+    if (texCoord.y > 0) {
+      let s = textureLoad(defendedStrengthTex, texCoord + vec2i(0, -1), 0).x;
+      if (s <= 0.001) {
+        dist = min(dist, fy);
+      }
+    }
+    if (texCoord.y + 1 < i32(mapRes.y)) {
+      let s = textureLoad(defendedStrengthTex, texCoord + vec2i(0, 1), 0).x;
+      if (s <= 0.001) {
+        dist = min(dist, 1.0 - fy);
+      }
+    }
+
+    if (dist < 1e8) {
+      let pxPerTile = max(viewScale, 0.001);
+      let aaTiles = 1.0 / pxPerTile;
+      let thicknessTiles = 1.5 / pxPerTile;
+      let line = 1.0 - smoothstep(thicknessTiles, thicknessTiles + aaTiles, dist);
+
+      let baseBorderRgb = textureLoad(paletteTex, vec2i(i32(owner) + 10, 1), 0).rgb;
+      let ringRgb = mix(baseBorderRgb, vec3f(1.0, 1.0, 1.0), 0.5);
+      outColor = vec4f(
+        mix(outColor.rgb, ringRgb, clamp(line * 0.65, 0.0, 1.0)),
+        outColor.a,
+      );
+    }
+  }
+
+  // Apply hover highlight if needed
+  if (highlightId > 0.5) {
+    let alpha = select(0.65, 0.0, altView > 0.5);
+
+    if (alpha > 0.0 && owner != 0u && abs(f32(owner) - highlightId) < 0.5) {
+      let pulse = 0.5 + 0.5 * sin(timeSec * 6.2831853);
+      let strength = 0.15 + 0.15 * pulse;
+      let highlightedRgb = mix(outColor.rgb, vec3f(1.0, 1.0, 1.0), strength);
+      outColor = vec4f(highlightedRgb, outColor.a);
+    }
+  }
+
+  return outColor;
+}
diff --git a/src/client/graphics/webgpu/shaders/render/territory.wgsl b/src/client/graphics/webgpu/shaders/render/territory.wgsl
index 9f89903c7..a234c5a63 100644
--- a/src/client/graphics/webgpu/shaders/render/territory.wgsl
+++ b/src/client/graphics/webgpu/shaders/render/territory.wgsl
@@ -1,7 +1,9 @@
 struct Uniforms {
   mapResolution_viewScale_time: vec4f, // x=mapW, y=mapH, z=viewScale, w=timeSec
   viewOffset_alt_highlight: vec4f,     // x=offX, y=offY, z=alternativeView, w=highlightOwnerId
-  viewSize_pad: vec4f,                // x=viewW, y=viewH, z=borderMode, w unused
+  viewSize_pad: vec4f,                // x=viewW, y=viewH, z=myPlayerSmallId, w unused
+  shaderParams0: vec4f,
+  shaderParams1: vec4f,
 };
 
 @group(0) @binding(0) var<uniform> u: Uniforms;
@@ -9,6 +11,8 @@ struct Uniforms {
 @group(0) @binding(2) var defendedStrengthTex: texture_2d<f32>;
 @group(0) @binding(3) var paletteTex: texture_2d<f32>;
 @group(0) @binding(4) var terrainTex: texture_2d<f32>;
+@group(0) @binding(5) var ownerIndexTex: texture_2d<u32>;
+@group(0) @binding(6) var relationsTex: texture_2d<u32>;
 
 @vertex
 fn vsMain(@builtin(vertex_index) vi: u32) -> @builtin(position) vec4f {
@@ -30,7 +34,13 @@ fn fsMain(@builtin(position) pos: vec4f) -> @location(0) vec4f {
   let altView = u.viewOffset_alt_highlight.z;
   let highlightId = u.viewOffset_alt_highlight.w;
   let viewSize = u.viewSize_pad.xy;
-  let borderMode = u.viewSize_pad.z;
+  let borderMode = u.shaderParams0.x;
+  let thicknessPx = u.shaderParams0.y;
+  let borderStrength = u.shaderParams0.z;
+  let glowStrength = u.shaderParams0.w;
+  let glowRadiusMul = u.shaderParams1.x;
+  let drawDefendedRadius = u.shaderParams1.y;
+  let disableDefendedTint = u.shaderParams1.z;
 
   // WebGPU fragment position is top-left origin and at pixel centers (0.5, 1.5, ...).
   let viewCoord = vec2f(pos.x - 0.5, pos.y - 0.5);
@@ -55,11 +65,18 @@ fn fsMain(@builtin(position) pos: vec4f) -> @location(0) vec4f {
     // Player colors start at index 10
     let c = textureLoad(paletteTex, vec2i(i32(owner) + 10, 0), 0);
     var territoryRgb = c.rgb;
-    territoryRgb = mix(
-      territoryRgb,
-      vec3f(1.0, 0.0, 1.0),
-      clamp(0.8 * defendedStrength, 0.1, 0.35),
-    );
+    if (disableDefendedTint <= 0.5) {
+      let defendedTint = select(
+        0.0,
+        clamp(0.8 * defendedStrength, 0.1, 0.35),
+        defendedStrength > 0.001,
+      );
+      territoryRgb = mix(
+        territoryRgb,
+        vec3f(1.0, 0.0, 1.0),
+        defendedTint,
+      );
+    }
     if (hasFallout) {
       // Fallout color is at index 0
       let falloutColor = textureLoad(paletteTex, vec2i(0, 0), 0).rgb;
@@ -117,28 +134,74 @@ fn fsMain(@builtin(position) pos: vec4f) -> @location(0) vec4f {
       // Mode 1: thin black border.
       // Mode 2: thicker black border + obvious tinted glow.
       let isGlow = borderMode > 1.5;
-      let thicknessPx = select(1.0, 3.0, isGlow);
       let thicknessTiles = thicknessPx / pxPerTile;
 
       let line = 1.0 - smoothstep(thicknessTiles, thicknessTiles + aaTiles, dist);
       outColor = vec4f(
-        mix(outColor.rgb, vec3f(0.0, 0.0, 0.0), clamp(line * 0.95, 0.0, 0.95)),
+        mix(outColor.rgb, vec3f(0.0, 0.0, 0.0), clamp(line * borderStrength, 0.0, 1.0)),
         outColor.a,
       );
 
       if (isGlow) {
-        let glowTiles = (thicknessPx * 5.0) / pxPerTile;
+        let glowTiles = (thicknessPx * glowRadiusMul) / pxPerTile;
         let glow = 1.0 - smoothstep(glowTiles, glowTiles + aaTiles * 3.0, dist);
         let ownerRgb = textureLoad(paletteTex, vec2i(i32(owner) + 10, 0), 0).rgb;
         let glowColor = mix(vec3f(1.0, 1.0, 1.0), ownerRgb, 0.85);
         outColor = vec4f(
-          mix(outColor.rgb, glowColor, clamp(glow * 0.35, 0.0, 0.35)),
+          mix(outColor.rgb, glowColor, clamp(glow * glowStrength, 0.0, 1.0)),
           outColor.a,
         );
       }
     }
   }
 
+  // Debug: defended radius boundary (based on defendedStrengthTex coverage).
+  if (drawDefendedRadius > 0.5 && defendedStrength > 0.001 && owner != 0u) {
+    let fx = fract(mapCoord.x);
+    let fy = fract(mapCoord.y);
+
+    var dist = 1e9;
+
+    if (texCoord.x > 0) {
+      let s = textureLoad(defendedStrengthTex, texCoord + vec2i(-1, 0), 0).x;
+      if (s <= 0.001) {
+        dist = min(dist, fx);
+      }
+    }
+    if (texCoord.x + 1 < i32(mapRes.x)) {
+      let s = textureLoad(defendedStrengthTex, texCoord + vec2i(1, 0), 0).x;
+      if (s <= 0.001) {
+        dist = min(dist, 1.0 - fx);
+      }
+    }
+    if (texCoord.y > 0) {
+      let s = textureLoad(defendedStrengthTex, texCoord + vec2i(0, -1), 0).x;
+      if (s <= 0.001) {
+        dist = min(dist, fy);
+      }
+    }
+    if (texCoord.y + 1 < i32(mapRes.y)) {
+      let s = textureLoad(defendedStrengthTex, texCoord + vec2i(0, 1), 0).x;
+      if (s <= 0.001) {
+        dist = min(dist, 1.0 - fy);
+      }
+    }
+
+    if (dist < 1e8) {
+      let pxPerTile = max(viewScale, 0.001);
+      let aaTiles = 1.0 / pxPerTile;
+      let thicknessTiles = 1.5 / pxPerTile;
+      let line = 1.0 - smoothstep(thicknessTiles, thicknessTiles + aaTiles, dist);
+
+      let borderRgb = textureLoad(paletteTex, vec2i(i32(owner) + 10, 1), 0).rgb;
+      let ringRgb = mix(borderRgb, vec3f(1.0, 1.0, 1.0), 0.5);
+      outColor = vec4f(
+        mix(outColor.rgb, ringRgb, clamp(line * 0.65, 0.0, 1.0)),
+        outColor.a,
+      );
+    }
+  }
+
   // Apply hover highlight if needed
   if (highlightId > 0.5) {
     let alpha = select(0.65, 0.0, altView > 0.5);
diff --git a/src/core/game/UserSettings.ts b/src/core/game/UserSettings.ts
index 74796e151..83d7e7710 100644
--- a/src/core/game/UserSettings.ts
+++ b/src/core/game/UserSettings.ts
@@ -55,6 +55,10 @@ export class UserSettings {
     return this.get("settings.performanceOverlay", false);
   }
 
+  webgpuDebug(): boolean {
+    return this.get("settings.webgpuDebug", true);
+  }
+
   alertFrame() {
     return this.get("settings.alertFrame", true);
   }
@@ -87,10 +91,6 @@ export class UserSettings {
     return this.get("settings.territoryPatterns", true);
   }
 
-  territoryBorderMode(): number {
-    return this.getInt("settings.territoryBorderMode", 1);
-  }
-
   cursorCostLabel() {
     const legacy = this.get("settings.ghostPricePill", true);
     return this.get("settings.cursorCostLabel", legacy);
@@ -118,6 +118,10 @@ export class UserSettings {
     this.set("settings.performanceOverlay", !this.performanceOverlay());
   }
 
+  toggleWebgpuDebug() {
+    this.set("settings.webgpuDebug", !this.webgpuDebug());
+  }
+
   toggleAlertFrame() {
     this.set("settings.alertFrame", !this.alertFrame());
   }