diff --git a/public/js/buildings/arena.js b/public/js/buildings/arena.js
index 81950f7..79b8f9d 100644
--- a/public/js/buildings/arena.js
+++ b/public/js/buildings/arena.js
@@ -189,6 +189,86 @@ function injectArenaStyles() {
     .arena-btn-ready.active { border-color:#8ae060; color:#c0f0a0; cursor:default; }
     .arena-searching-box { font-family:"Cinzel",serif; font-size:11px; color:#dceb15; text-align:center; padding:9px; border:1px solid rgba(255,215,80,.3); border-radius:7px; margin-top:7px; animation:pulse 2s ease-in-out infinite; }
 
+    /* ── Deck-Auswahl ── */
+    #deck-select-overlay { animation: arenaFadeIn .2s ease; }
+    .deck-select-box {
+      background: linear-gradient(#2a1a08, #1a0f04);
+      border: 2px solid #c8960c;
+      border-radius: 12px;
+      padding: 20px;
+      width: min(360px, 90vw);
+      max-height: 80vh;
+      display: flex;
+      flex-direction: column;
+      gap: 12px;
+      box-shadow: 0 20px 60px rgba(0,0,0,0.8);
+    }
+    .deck-select-title {
+      font-family: "Cinzel", serif;
+      font-size: 16px;
+      color: #f0d060;
+      letter-spacing: 2px;
+      text-align: center;
+    }
+    .deck-select-hint {
+      font-family: "Cinzel", serif;
+      font-size: 11px;
+      color: #a08060;
+      text-align: center;
+      margin: 0;
+      line-height: 1.6;
+    }
+    .deck-select-list {
+      display: flex;
+      flex-direction: column;
+      gap: 6px;
+      overflow-y: auto;
+      max-height: 260px;
+    }
+    .deck-select-row {
+      display: flex;
+      align-items: center;
+      justify-content: space-between;
+      padding: 10px 14px;
+      background: rgba(255,255,255,0.03);
+      border: 1px solid #3a2810;
+      border-radius: 7px;
+      cursor: pointer;
+      transition: border-color .15s, background .15s;
+    }
+    .deck-select-row:not(.deck-empty):hover { border-color: #c8960c; background: rgba(200,150,42,0.08); }
+    .deck-select-row.deck-selected { border-color: #f0d060; background: rgba(200,150,42,0.12); }
+    .deck-select-row.deck-empty { opacity: .4; cursor: not-allowed; }
+    .deck-select-name  { font-family: "Cinzel", serif; font-size: 12px; color: #f0d9a6; }
+    .deck-select-count { font-size: 11px; color: #a08060; }
+    .deck-select-warn  { font-size: 10px; color: #e07070; }
+    .deck-select-actions { display: flex; gap: 10px; justify-content: flex-end; }
+    .deck-select-cancel {
+      background: none;
+      border: 1px solid rgba(255,200,80,.3);
+      color: #a08060;
+      font-family: "Cinzel", serif;
+      font-size: 11px;
+      padding: 7px 14px;
+      border-radius: 6px;
+      cursor: pointer;
+    }
+    .deck-select-cancel:hover { border-color: rgba(255,200,80,.6); color: #c8a060; }
+    .deck-select-confirm {
+      background: linear-gradient(#4a3010, #2a1a06);
+      border: 2px solid #c8960c;
+      color: #f0d060;
+      font-family: "Cinzel", serif;
+      font-size: 11px;
+      padding: 7px 16px;
+      border-radius: 6px;
+      cursor: pointer;
+      font-weight: bold;
+      transition: .15s;
+    }
+    .deck-select-confirm:hover:not(:disabled) { border-color: #f0d060; background: linear-gradient(#5a4020,#3a2a10); }
+    .deck-btn-disabled { opacity: .4; cursor: not-allowed !important; }
+
     #arena-backdrop { position:fixed; inset:0; background:rgba(0,0,0,.82); backdrop-filter:blur(5px); z-index:9998; animation:arenaFadeIn .25s ease; }
     #arena-popup { position:fixed; inset:50px; z-index:9999; display:flex; flex-direction:column; border-radius:14px; overflow:hidden; box-shadow:0 0 0 1px rgba(255,215,80,.35),0 30px 90px rgba(0,0,0,.85); animation:arenaScaleIn .28s cubic-bezier(.22,1,.36,1); }
     #arena-popup-titlebar { display:flex; align-items:center; justify-content:space-between; background:rgba(10,8,5,.95); border-bottom:1px solid rgba(255,215,80,.3); padding:0 16px; height:42px; flex-shrink:0; }
@@ -209,18 +289,19 @@ function injectArenaStyles() {
 function getSocket() { return window._socket || null; }
 
 /* ── State ─────────────────────────────────────────────────*/
-let myArenaData = null;
-let my2v2TeamId = null;
-let my4v4TeamId = null;
+let myArenaData    = null;
+let my2v2TeamId    = null;
+let my4v4TeamId    = null;
+let selectedDeckId = null;  // Gewähltes Deck für das nächste Match
 
 /* ── Modus-Initialisierung ─────────────────────────────────*/
 function initArenaModes() {
   document.querySelectorAll(".arena-mode-card").forEach(card => {
     card.addEventListener("click", () => {
       const mode = card.dataset.mode;
-      if      (mode === "1v1") handle1v1Click(card);
-      else if (mode === "2v2") openTeamLobby("2v2");
-      else if (mode === "4v4") openTeamLobby("4v4");
+      if      (mode === "1v1") showDeckSelector(() => handle1v1Click(card));
+      else if (mode === "2v2") showDeckSelector(() => openTeamLobby("2v2"));
+      else if (mode === "4v4") showDeckSelector(() => openTeamLobby("4v4"));
     });
   });
 
@@ -247,6 +328,90 @@ function initArenaModes() {
   });
 }
 
+/* ── Deck-Auswahl Popup ────────────────────────────────────*/
+async function showDeckSelector(onConfirm) {
+  // Decks laden
+  let decks = [];
+  try {
+    const res = await fetch("/api/decks");
+    if (!res.ok) throw new Error();
+    decks = await res.json();
+  } catch {
+    showArenaError("Decks konnten nicht geladen werden.");
+    return;
+  }
+
+  // Overlay erstellen
+  const overlay = document.createElement("div");
+  overlay.id = "deck-select-overlay";
+  overlay.style.cssText = [
+    "position:fixed","inset:0","z-index:9997",
+    "background:rgba(0,0,0,0.75)","display:flex",
+    "align-items:center","justify-content:center"
+  ].join(";");
+
+  if (decks.length === 0) {
+    // Kein Deck vorhanden
+    overlay.innerHTML = `
+      <div class="deck-select-box">
+        <div class="deck-select-title">⚠️ Kein Deck vorhanden</div>
+        <p class="deck-select-hint">
+          Du musst zuerst ein Deck erstellen bevor du kämpfen kannst.<br>
+          Gehe zur <strong>Burg</strong> → Kartendeck um ein Deck zu erstellen.
+        </p>
+        <button class="deck-select-cancel" id="deck-close-btn">Schließen</button>
+      </div>`;
+    document.body.appendChild(overlay);
+    document.getElementById("deck-close-btn").addEventListener("click", () => overlay.remove());
+    return;
+  }
+
+  // Decks als Auswahl anzeigen
+  const deckRows = decks.map(d => `
+    <div class="deck-select-row ${d.card_count === 0 ? "deck-empty" : ""}"
+         data-id="${d.id}" data-count="${d.card_count}">
+      <span class="deck-select-name">🃏 ${d.name}</span>
+      <span class="deck-select-count">${d.card_count} Karten</span>
+      ${d.card_count === 0 ? "<span class='deck-select-warn'>Leer</span>" : ""}
+    </div>`).join("");
+
+  overlay.innerHTML = `
+    <div class="deck-select-box">
+      <div class="deck-select-title">⚔️ Deck auswählen</div>
+      <p class="deck-select-hint">Mit welchem Deck möchtest du kämpfen?</p>
+      <div class="deck-select-list">${deckRows}</div>
+      <div class="deck-select-actions">
+        <button class="deck-select-cancel" id="deck-cancel-btn">Abbrechen</button>
+        <button class="deck-select-confirm deck-btn-disabled" id="deck-confirm-btn" disabled>Kämpfen ⚔️</button>
+      </div>
+    </div>`;
+
+  document.body.appendChild(overlay);
+
+  // Deck anklicken
+  overlay.querySelectorAll(".deck-select-row:not(.deck-empty)").forEach(row => {
+    row.addEventListener("click", () => {
+      overlay.querySelectorAll(".deck-select-row").forEach(r => r.classList.remove("deck-selected"));
+      row.classList.add("deck-selected");
+      selectedDeckId = Number(row.dataset.id);
+      const btn = document.getElementById("deck-confirm-btn");
+      btn.disabled = false;
+      btn.classList.remove("deck-btn-disabled");
+    });
+  });
+
+  document.getElementById("deck-cancel-btn").addEventListener("click", () => {
+    overlay.remove();
+    selectedDeckId = null;
+  });
+
+  document.getElementById("deck-confirm-btn").addEventListener("click", () => {
+    if (!selectedDeckId) return;
+    overlay.remove();
+    onConfirm();
+  });
+}
+
 /* ── 1v1 ───────────────────────────────────────────────────*/
 async function handle1v1Click(card) {
   const socket = getSocket();