diff --git a/backend/src/main/java/de/szut/casino/CasinoApplication.java b/backend/src/main/java/de/szut/casino/CasinoApplication.java
index 8c99f02..cc22e2c 100644
--- a/backend/src/main/java/de/szut/casino/CasinoApplication.java
+++ b/backend/src/main/java/de/szut/casino/CasinoApplication.java
@@ -1,10 +1,19 @@
 package de.szut.casino;
 
+import de.szut.casino.lootboxes.LootBoxEntity;
+import de.szut.casino.lootboxes.LootBoxRepository;
+import de.szut.casino.lootboxes.RewardEntity;
+import de.szut.casino.lootboxes.RewardRepository;
+import org.springframework.boot.CommandLineRunner;
 import org.springframework.boot.SpringApplication;
 import org.springframework.boot.autoconfigure.SpringBootApplication;
 import org.springframework.context.annotation.Bean;
 import org.springframework.web.client.RestTemplate;
 
+import java.math.BigDecimal;
+import java.util.Arrays;
+import java.util.List;
+
 @SpringBootApplication
 public class CasinoApplication {
 
@@ -16,4 +25,64 @@ public class CasinoApplication {
     public static RestTemplate restTemplate() {
         return new RestTemplate();
     }
+
+    @Bean
+    public CommandLineRunner initData(LootBoxRepository lootBoxRepository, RewardRepository rewardRepository) {
+        return _ -> {
+            if (lootBoxRepository.count() == 0) {
+                // Create basic LootBox
+                LootBoxEntity basicLootBox = new LootBoxEntity();
+                basicLootBox.setName("Basic LootBox");
+                basicLootBox.setPrice(new BigDecimal("1.99"));
+
+                // Create premium LootBox
+                LootBoxEntity premiumLootBox = new LootBoxEntity();
+                premiumLootBox.setName("Premium LootBox");
+                premiumLootBox.setPrice(new BigDecimal("4.99"));
+
+                // Save LootBoxes first to get IDs
+                lootBoxRepository.saveAll(Arrays.asList(basicLootBox, premiumLootBox));
+
+                // Create rewards for basic LootBox
+                RewardEntity commonReward = new RewardEntity();
+                commonReward.setValue(new BigDecimal("0.50"));
+                commonReward.setProbability(new BigDecimal("70.00"));
+                commonReward.setLootBoxes(List.of(premiumLootBox));
+
+                RewardEntity rareReward = new RewardEntity();
+                rareReward.setValue(new BigDecimal("2.00"));
+                rareReward.setProbability(new BigDecimal("25.00"));
+                rareReward.setLootBoxes(List.of(basicLootBox));
+
+                RewardEntity epicReward = new RewardEntity();
+                epicReward.setValue(new BigDecimal("5.00"));
+                epicReward.setProbability(new BigDecimal("5.00"));
+                epicReward.setLootBoxes(List.of(basicLootBox));
+
+                // Create rewards for premium LootBox
+                RewardEntity premiumCommon = new RewardEntity();
+                premiumCommon.setValue(new BigDecimal("2.00"));
+                premiumCommon.setProbability(new BigDecimal("60.00"));
+                premiumCommon.setLootBoxes(List.of(premiumLootBox));
+
+                RewardEntity premiumRare = new RewardEntity();
+                premiumRare.setValue(new BigDecimal("5.00"));
+                premiumRare.setProbability(new BigDecimal("30.00"));
+                premiumRare.setLootBoxes(List.of(premiumLootBox));
+
+                RewardEntity legendaryReward = new RewardEntity();
+                legendaryReward.setValue(new BigDecimal("15.00"));
+                legendaryReward.setProbability(new BigDecimal("10.00"));
+                legendaryReward.setLootBoxes(List.of(premiumLootBox));
+
+                rewardRepository.saveAll(Arrays.asList(
+                        commonReward, rareReward, epicReward,
+                        premiumCommon, premiumRare, legendaryReward
+                ));
+                System.out.println("Initial LootBoxes and rewards created successfully");
+            } else {
+                System.out.println("LootBoxes already exist, skipping initialization");
+            }
+        };
+    }
 }
diff --git a/backend/src/main/java/de/szut/casino/lootboxes/LootBoxEntity.java b/backend/src/main/java/de/szut/casino/lootboxes/LootBoxEntity.java
index 7138bf3..bd6c588 100644
--- a/backend/src/main/java/de/szut/casino/lootboxes/LootBoxEntity.java
+++ b/backend/src/main/java/de/szut/casino/lootboxes/LootBoxEntity.java
@@ -29,6 +29,11 @@ public class LootBoxEntity {
     @Column(precision = 19, scale = 2)
     private BigDecimal price;
 
-    @OneToMany(mappedBy = "lootBox", cascade = CascadeType.ALL, orphanRemoval = true)
+    @ManyToMany(cascade = {CascadeType.PERSIST, CascadeType.MERGE})
+    @JoinTable(
+            name = "lootbox_reward",
+            joinColumns = @JoinColumn(name = "lootbox_id"),
+            inverseJoinColumns = @JoinColumn(name = "reward_id")
+    )
     private List<RewardEntity> rewards = new ArrayList<>();
 }
diff --git a/backend/src/main/java/de/szut/casino/lootboxes/LootBoxRepository.java b/backend/src/main/java/de/szut/casino/lootboxes/LootBoxRepository.java
index 96ba188..472388e 100644
--- a/backend/src/main/java/de/szut/casino/lootboxes/LootBoxRepository.java
+++ b/backend/src/main/java/de/szut/casino/lootboxes/LootBoxRepository.java
@@ -1,6 +1,5 @@
 package de.szut.casino.lootboxes;
 
-import de.szut.casino.blackjack.BlackJackGameEntity;
 import org.springframework.data.jpa.repository.JpaRepository;
 import org.springframework.stereotype.Service;
 
diff --git a/backend/src/main/java/de/szut/casino/lootboxes/RewardEntity.java b/backend/src/main/java/de/szut/casino/lootboxes/RewardEntity.java
index 0c1d21d..97ad6d1 100644
--- a/backend/src/main/java/de/szut/casino/lootboxes/RewardEntity.java
+++ b/backend/src/main/java/de/szut/casino/lootboxes/RewardEntity.java
@@ -1,14 +1,16 @@
 package de.szut.casino.lootboxes;
 
 import com.fasterxml.jackson.annotation.JsonBackReference;
-import com.fasterxml.jackson.annotation.JsonManagedReference;
-import de.szut.casino.blackjack.BlackJackGameEntity;
 import jakarta.persistence.*;
+import lombok.Getter;
+import lombok.Setter;
 
 import java.math.BigDecimal;
 import java.util.ArrayList;
 import java.util.List;
 
+@Getter
+@Setter
 @Entity
 public class RewardEntity {
     @Id
@@ -21,8 +23,6 @@ public class RewardEntity {
     @Column(precision = 5, scale = 2)
     private BigDecimal probability;
 
-    @ManyToOne
-    @JoinColumn(name = "lootBox_id", nullable = false)
-    @JsonBackReference
-    private LootBoxEntity lootBox;
+    @ManyToMany(mappedBy = "rewards")
+    private List<LootBoxEntity> lootBoxes = new ArrayList<>();
 }