diff --git a/cmd/client/connection_native.go b/cmd/client/connection_native.go
index 9915781..97875b6 100644
--- a/cmd/client/connection_native.go
+++ b/cmd/client/connection_native.go
@@ -85,6 +85,13 @@ func (g *Game) wsReadPump() {
 			payloadBytes, _ := json.Marshal(msg.Payload)
 			var state game.GameState
 			if err := json.Unmarshal(payloadBytes, &state); err == nil {
+				// Out-of-Order-Erkennung: Ignoriere alte Updates
+				if state.Sequence > 0 && state.Sequence <= g.lastRecvSeq {
+					// Alte Nachricht - ignorieren
+					continue
+				}
+				g.lastRecvSeq = state.Sequence
+
 				// Server Reconciliation für lokalen Spieler (VOR dem Lock)
 				for _, p := range state.Players {
 					if p.Name == g.playerName {
diff --git a/cmd/client/connection_wasm.go b/cmd/client/connection_wasm.go
index d986174..1839bec 100644
--- a/cmd/client/connection_wasm.go
+++ b/cmd/client/connection_wasm.go
@@ -72,6 +72,13 @@ func (g *Game) connectToServer() {
 			payloadBytes, _ := json.Marshal(msg.Payload)
 			var state game.GameState
 			if err := json.Unmarshal(payloadBytes, &state); err == nil {
+				// Out-of-Order-Erkennung: Ignoriere alte Updates
+				if state.Sequence > 0 && state.Sequence <= g.lastRecvSeq {
+					// Alte Nachricht - ignorieren
+					return nil
+				}
+				g.lastRecvSeq = state.Sequence
+
 				// Server Reconciliation für lokalen Spieler (VOR dem Lock)
 				for _, p := range state.Players {
 					if p.Name == g.playerName {
diff --git a/cmd/client/main.go b/cmd/client/main.go
index ff97511..570ce4b 100644
--- a/cmd/client/main.go
+++ b/cmd/client/main.go
@@ -92,6 +92,7 @@ type Game struct {
 	pendingInputs   map[uint32]InputState // Noch nicht bestätigte Inputs
 	lastServerSeq   uint32                // Letzte vom Server bestätigte Sequenz
 	predictionMutex sync.Mutex            // Mutex für pendingInputs
+	lastRecvSeq     uint32                // Letzte empfangene Server-Sequenznummer (für Out-of-Order-Erkennung)
 
 	// Smooth Correction
 	correctionX float64 // Verbleibende Korrektur in X
diff --git a/pkg/game/data.go b/pkg/game/data.go
index 4ae5457..adc316e 100644
--- a/pkg/game/data.go
+++ b/pkg/game/data.go
@@ -113,6 +113,7 @@ type GameState struct {
 	CollectedCoins    map[string]bool        `json:"collected_coins"`    // Welche Coins wurden eingesammelt (Key: ChunkID_ObjectIndex)
 	CollectedPowerups map[string]bool        `json:"collected_powerups"` // Welche Powerups wurden eingesammelt
 	MovingPlatforms   []MovingPlatformSync   `json:"moving_platforms"`   // Bewegende Plattformen
+	Sequence          uint32                 `json:"sequence"`           // Sequenznummer für Out-of-Order-Erkennung
 }
 
 // MovingPlatformSync: Synchronisiert die Position einer bewegenden Plattform
diff --git a/pkg/server/room.go b/pkg/server/room.go
index aee2d81..81a382a 100644
--- a/pkg/server/room.go
+++ b/pkg/server/room.go
@@ -83,6 +83,7 @@ type Room struct {
 	ChunkSpawnedCount map[string]int    // Wie oft wurde jeder Chunk gespawnt
 	MovingPlatforms   []*MovingPlatform // Aktive bewegende Plattformen
 	firstBroadcast    bool              // Wurde bereits geloggt?
+	sequence          uint32            // Sequenznummer für Broadcasts
 
 	stopChan chan struct{}
 
@@ -784,6 +785,9 @@ func (r *Room) Broadcast() {
 	r.Mutex.RLock()
 	defer r.Mutex.RUnlock()
 
+	// Sequenznummer erhöhen
+	r.sequence++
+
 	state := game.GameState{
 		RoomID:            r.ID,
 		Players:           make(map[string]game.PlayerState),
@@ -797,6 +801,7 @@ func (r *Room) Broadcast() {
 		CollectedCoins:    r.CollectedCoins,
 		CollectedPowerups: r.CollectedPowerups,
 		MovingPlatforms:   make([]game.MovingPlatformSync, 0, len(r.MovingPlatforms)),
+		Sequence:          r.sequence,
 	}
 
 	for id, p := range r.Players {