diff --git a/server.js b/server.js
index 05ff743..51edefd 100644
--- a/server.js
+++ b/server.js
@@ -653,10 +653,16 @@ function buildDefaultDeck() {
       "empathie"
     ],
 
+    [
+      "Cachotier",
+      "La prochaine carte jouée ne sera pas révélée à l'adversaire.",
+      "cachotier"
+    ],
+
     // facile et intéresssant
     // ["intrication quantique","Deux pièces sont intriquées. Quand l'une bouge, l'autre bouge de la même manière."],
     // ['kurby','Choisis une pièce. À sa prochaine capture, récupère tous les mouvements de la pièce capturée.'],
-    // ["cachotier", "La prochaine carte jouée ne sera pas révélée à l'adversaire."],
+    
     // ['défausse','Le joueur adverse défausse une carte de son choix'],
     // ['glue','Toutes les pièces autour de la pièce désignée ne peuvent pas bouger tant que cette dernière ne bouge pas'],
     // ['immunité à la capture','Désigne une pièce qui ne pourra pas être capturée au prochain tour'],
@@ -5076,6 +5082,37 @@ io.on("connection", (socket) => {
           console.error("rebondir effect error", e);
         }
       }
+
+      // cachotier
+      else if (cardId === "cachotier") {
+        try {
+          room.activeCardEffects = room.activeCardEffects || [];
+          const effect = {
+            id: played.id,
+            type: "cachotier",
+            playerId: senderId,
+            // This effect lasts until the player plays their next card
+            usesRemaining: 1,
+            ts: Date.now(),
+          };
+          room.activeCardEffects.push(effect);
+          try {
+            // Only notify the player who played the card, not the opponent
+            const owner = (room.players || []).find((p) => p.id === senderId);
+            if (owner && owner.socketId)
+              io.to(owner.socketId).emit("card:effect:applied", {
+                roomId: room.id,
+                effect,
+              });
+          } catch (_) {}
+          played.payload = Object.assign({}, payload, {
+            applied: "cachotier",
+            appliedToPlayer: senderId,
+          });
+        } catch (e) {
+          console.error("cachotier effect error", e);
+        }
+      }
     } catch (e) {
       console.error("card:play effect error", e);
     }
@@ -5090,7 +5127,66 @@ io.on("connection", (socket) => {
     } catch (e) {
       console.error("mark card played error", e);
     }
-    io.to(roomId).emit("card:played", played);
+
+    // Check if cachotier effect is active for the player who played the card
+    let cachotierActive = false;
+    let cachotierEffect = null;
+    try {
+      const active = room.activeCardEffects || [];
+      cachotierEffect = active.find(
+        (e) => e && e.type === "cachotier" && e.playerId === senderId && e.usesRemaining > 0
+      );
+      // Only apply cachotier if this is NOT the cachotier card itself being played
+      if (cachotierEffect && cardId !== "cachotier") {
+        cachotierActive = true;
+        // Consume the cachotier effect
+        cachotierEffect.usesRemaining = 0;
+        // Remove the effect from active effects
+        room.activeCardEffects = active.filter((e) => e !== cachotierEffect);
+        try {
+          io.to(room.id).emit("card:effect:removed", {
+            roomId: room.id,
+            effectId: cachotierEffect.id,
+            type: "cachotier",
+            playerId: cachotierEffect.playerId,
+          });
+        } catch (_) {}
+      }
+    } catch (e) {
+      console.error("cachotier check error", e);
+    }
+
+    if (cachotierActive) {
+      // Send hidden version to opponent, full version to the player who played
+      try {
+        const hiddenPlayed = {
+          id: played.id,
+          playerId: played.playerId,
+          cardId: "hidden",
+          payload: { hidden: true },
+          ts: played.ts,
+          card: { id: "hidden", title: "Carte cachée", description: "Cette carte a été jouée secrètement.", hidden: true },
+          _cachotier: true,
+        };
+        // Send to each player individually
+        (room.players || []).forEach((p) => {
+          if (!p || !p.socketId) return;
+          if (p.id === senderId) {
+            // Owner sees the full card
+            io.to(p.socketId).emit("card:played", played);
+          } else {
+            // Opponent sees hidden card
+            io.to(p.socketId).emit("card:played", hiddenPlayed);
+          }
+        });
+      } catch (e) {
+        console.error("cachotier emit error", e);
+        // Fallback to normal emit
+        io.to(roomId).emit("card:played", played);
+      }
+    } else {
+      io.to(roomId).emit("card:played", played);
+    }
     try {
       const countsAsMove = cardId === "inversion";
       if (countsAsMove) {