diff --git a/app/src/main/java/org/secuso/privacyfriendlysudoku/controller/NewLevelManager.java b/app/src/main/java/org/secuso/privacyfriendlysudoku/controller/NewLevelManager.java
index b656bb5..7aca04a 100644
--- a/app/src/main/java/org/secuso/privacyfriendlysudoku/controller/NewLevelManager.java
+++ b/app/src/main/java/org/secuso/privacyfriendlysudoku/controller/NewLevelManager.java
@@ -40,6 +40,9 @@ public class NewLevelManager {
     public static int PRE_SAVES_MIN = 3;
     public static int PRE_SAVES_MAX = 10;
 
+    private final double CHALLENGE_GENERATION_PROBABILITY = 0.9;
+
+
     public static NewLevelManager getInstance(Context context, SharedPreferences settings) {
         if(instance == null) {
             instance = new NewLevelManager(context, settings);
@@ -80,11 +83,17 @@ public class NewLevelManager {
 
     public int[] loadDailySudoku() {
         DateFormat dateFormat = new SimpleDateFormat("dd/MM/yyyy");
-        Date date = new Date();
-        String toHash = "Sudoku/.PrivacyFriendly/." + dateFormat.format(date);
-
+        String toHash = "Sudoku/.PrivacyFriendly/." + dateFormat.format(new Date());
+        boolean generateChallenge = new Random(toHash.hashCode()).nextDouble() >= CHALLENGE_GENERATION_PROBABILITY;
         QQWingController controller = new QQWingController();
-        return controller.generateFromSeed(toHash.hashCode());
+        int[] result;
+
+        if (generateChallenge) {
+            result = controller.generateFromSeed(toHash.hashCode(), GameDifficulty.Challenge);
+        } else {
+            result = controller.generateFromSeed(toHash.hashCode(), GameDifficulty.Unspecified);
+        }
+        return result;
     }
 
     public int[] loadLevel(GameType type, GameDifficulty diff) {
diff --git a/app/src/main/java/org/secuso/privacyfriendlysudoku/controller/QQWingController.java b/app/src/main/java/org/secuso/privacyfriendlysudoku/controller/QQWingController.java
index 2f44929..eb78863 100644
--- a/app/src/main/java/org/secuso/privacyfriendlysudoku/controller/QQWingController.java
+++ b/app/src/main/java/org/secuso/privacyfriendlysudoku/controller/QQWingController.java
@@ -53,13 +53,22 @@ public class QQWingController {
         return generated;
     }
 
-    public int[] generateFromSeed(int seed) {
+    public int[] generateFromSeed(int seed, GameDifficulty difficulty) {
         generated.clear();
-
         QQWing generator = new QQWing(GameType.Default_9x9, GameDifficulty.Unspecified);
-        generator.setRandom(seed);
-        generator.setRecordHistory(true);
-        generator.generatePuzzle();
+        boolean havePuzzle = false;
+
+        while(!havePuzzle) {
+            seed++;
+            generator.setRandom(seed);
+            generator.setRecordHistory(true);
+            generator.generatePuzzle();
+
+            if (difficulty == GameDifficulty.Unspecified && generator.getDifficulty() != GameDifficulty.Challenge
+                    || difficulty == generator.getDifficulty()) {
+                havePuzzle = true;
+            }
+        }
 
         generated.add(generator.getPuzzle());
         opts.gameType = GameType.Default_9x9;