diff --git a/frontend/components/chess/BlindfoldToggle.tsx b/frontend/components/chess/BlindfoldToggle.tsx
new file mode 100644
index 00000000..ca800522
--- /dev/null
+++ b/frontend/components/chess/BlindfoldToggle.tsx
@@ -0,0 +1,39 @@
+"use client";
+
+import React from "react";
+
+interface BlindfoldToggleProps {
+  blindfoldMode: boolean;
+  onToggle: (enabled: boolean) => void;
+}
+
+/**
+ * FE-51: blindfold mode toggle. Consumers apply `blindfoldMode` to piece
+ * rendering (e.g. `opacity: 0` on piece SVGs) while keeping hitboxes and
+ * legal-move logic untouched — this component only owns the on/off state.
+ */
+const BlindfoldToggle: React.FC<BlindfoldToggleProps> = ({
+  blindfoldMode,
+  onToggle,
+}) => {
+  return (
+    <label className="blindfold-toggle flex items-center gap-2 text-sm">
+      <input
+        type="checkbox"
+        checked={blindfoldMode}
+        onChange={(e) => onToggle(e.target.checked)}
+        aria-label="Blindfold mode"
+      />
+      Blindfold mode (hide pieces)
+    </label>
+  );
+};
+
+export const pieceStyleForBlindfold = (
+  blindfoldMode: boolean
+): React.CSSProperties => ({
+  opacity: blindfoldMode ? 0 : 1,
+  pointerEvents: "auto",
+});
+
+export default BlindfoldToggle;
diff --git a/frontend/components/chess/GameReviewSummary.tsx b/frontend/components/chess/GameReviewSummary.tsx
new file mode 100644
index 00000000..0ce5fd06
--- /dev/null
+++ b/frontend/components/chess/GameReviewSummary.tsx
@@ -0,0 +1,61 @@
+"use client";
+
+import React from "react";
+
+export type MoveClass =
+  | "brilliant"
+  | "great"
+  | "best"
+  | "inaccuracy"
+  | "mistake"
+  | "blunder";
+
+interface GameReviewSummaryProps {
+  whiteAccuracy: number;
+  blackAccuracy: number;
+  counts: Record<MoveClass, number>;
+  onRetryMistake?: () => void;
+}
+
+const BADGE: Record<MoveClass, string> = {
+  brilliant: "!!",
+  great: "!",
+  best: "★",
+  inaccuracy: "?!",
+  mistake: "?",
+  blunder: "??",
+};
+
+/**
+ * FE-50: game review summary card. Accuracy % and per-move classification
+ * are computed upstream (engine analysis) and passed in as props.
+ */
+const GameReviewSummary: React.FC<GameReviewSummaryProps> = ({
+  whiteAccuracy,
+  blackAccuracy,
+  counts,
+  onRetryMistake,
+}) => {
+  return (
+    <div className="game-review-summary p-4 rounded-lg border border-white/10">
+      <div className="flex justify-between text-sm mb-3">
+        <span>White accuracy: {whiteAccuracy.toFixed(1)}%</span>
+        <span>Black accuracy: {blackAccuracy.toFixed(1)}%</span>
+      </div>
+      <ul className="flex flex-wrap gap-3 text-sm">
+        {(Object.keys(BADGE) as MoveClass[]).map((cls) => (
+          <li key={cls}>
+            {BADGE[cls]} {cls}: {counts[cls] ?? 0}
+          </li>
+        ))}
+      </ul>
+      {counts.blunder > 0 && onRetryMistake && (
+        <button onClick={onRetryMistake} className="mt-3 px-3 py-1.5 rounded bg-red-600 text-white text-sm">
+          Retry Mistake
+        </button>
+      )}
+    </div>
+  );
+};
+
+export default GameReviewSummary;
diff --git a/frontend/components/chess/OfflinePlayView.tsx b/frontend/components/chess/OfflinePlayView.tsx
new file mode 100644
index 00000000..447ae6a1
--- /dev/null
+++ b/frontend/components/chess/OfflinePlayView.tsx
@@ -0,0 +1,57 @@
+"use client";
+
+import React, { useEffect, useState } from "react";
+
+interface OfflinePlayViewProps {
+  onStartOfflineGame: (elo: number) => void;
+}
+
+/**
+ * FE-49: minimal offline play-vs-Stockfish entry point.
+ * Actual Stockfish WASM worker + ServiceWorker caching are separate
+ * follow-up work — this wires the "Play Offline" affordance and Elo pick.
+ */
+const OfflinePlayView: React.FC<OfflinePlayViewProps> = ({
+  onStartOfflineGame,
+}) => {
+  const [isOffline, setIsOffline] = useState(false);
+  const [elo, setElo] = useState(1200);
+
+  useEffect(() => {
+    setIsOffline(!navigator.onLine);
+    const goOffline = () => setIsOffline(true);
+    const goOnline = () => setIsOffline(false);
+    window.addEventListener("offline", goOffline);
+    window.addEventListener("online", goOnline);
+    return () => {
+      window.removeEventListener("offline", goOffline);
+      window.removeEventListener("online", goOnline);
+    };
+  }, []);
+
+  if (!isOffline) return null;
+
+  return (
+    <div className="offline-play-view p-4 rounded-lg border border-yellow-500/40 bg-yellow-500/10">
+      <p className="text-sm mb-2">You&apos;re offline. Practice vs Stockfish instead?</p>
+      <input
+        type="range"
+        min={800}
+        max={2500}
+        step={100}
+        value={elo}
+        onChange={(e) => setElo(Number(e.target.value))}
+        aria-label="Stockfish Elo"
+      />
+      <span className="ml-2 text-sm">{elo} Elo</span>
+      <button
+        onClick={() => onStartOfflineGame(elo)}
+        className="block mt-3 px-4 py-2 rounded bg-yellow-600 text-white"
+      >
+        Play Offline
+      </button>
+    </div>
+  );
+};
+
+export default OfflinePlayView;
diff --git a/frontend/components/tournament/BerserkButton.tsx b/frontend/components/tournament/BerserkButton.tsx
new file mode 100644
index 00000000..5fa7bcab
--- /dev/null
+++ b/frontend/components/tournament/BerserkButton.tsx
@@ -0,0 +1,34 @@
+"use client";
+
+import React from "react";
+
+interface BerserkButtonProps {
+  isArenaMatch: boolean;
+  moveNumber: number;
+  onBerserk: () => void;
+}
+
+/**
+ * FE-52: Berserk button for Arena tournaments. Only active before the
+ * player's first move; dispatches a `BerserkMove` event upstream via
+ * `onBerserk`, which the game socket layer is responsible for sending.
+ */
+const BerserkButton: React.FC<BerserkButtonProps> = ({
+  isArenaMatch,
+  moveNumber,
+  onBerserk,
+}) => {
+  if (!isArenaMatch || moveNumber > 0) return null;
+
+  return (
+    <button
+      onClick={onBerserk}
+      aria-label="Berserk — halve your clock for bonus tournament points"
+      className="berserk-button px-4 py-2 rounded-md font-bold text-white bg-red-700 border-2 border-orange-400 animate-pulse shadow-[0_0_12px_rgba(255,80,0,0.8)]"
+    >
+      🔥 BERSERK
+    </button>
+  );
+};
+
+export default BerserkButton;