diff --git a/PartyModeChallenge/ChallengeRounds.cs b/PartyModeChallenge/ChallengeRounds.cs
index 5a40bc1e..95bf2b98 100644
--- a/PartyModeChallenge/ChallengeRounds.cs
+++ b/PartyModeChallenge/ChallengeRounds.cs
@@ -2,84 +2,250 @@
 using System.Collections.Generic;
 using System.Text;
 
+using Vocaluxe.Menu;
+
 namespace Vocaluxe.PartyModes
 {
     public class ChallengeRounds
     {
-        private List<ChallengeRound> _Rounds;
+        private Random _Rand;
+        private List<Combination> _Rounds;
+        private int _NumPlayer;
+
 
         public ChallengeRounds(int NumRounds, int NumPlayer, int NumPlayerAtOnce)
         {
-            BuildRounds(NumRounds, NumPlayer, NumPlayerAtOnce);
-        }
+            _Rounds = new List<Combination>();
+            _Rand = new Random(System.DateTime.Now.Millisecond);
 
-        public ChallengeRound GetRound(int RoundNr)
-        {
-            return null;
-        }
-
-        private void BuildRounds(int NumRounds, int NumPlayer, int NumPlayerAtOnce)
-        {
-            _Rounds = new List<ChallengeRound>();
-
-            if (NumPlayerAtOnce < 1 || NumPlayerAtOnce > 6 || NumPlayer < 1 || NumRounds < 1)
-                return;
-
-            switch (NumPlayerAtOnce)
+            if (NumPlayerAtOnce < 1 || NumRounds < 1 || NumPlayer == 0)
+                _NumPlayer = 0;
+            else
             {
-                case 1:
-                    for (int i = 0; i < NumRounds; i++)
-                    {
-                        
-                    }
-                    break;
-
-                case 2:
-                    break;
-
-                case 3:
-                    break;
-
-                case 4:
-                    break;
-
-                case 5:
-                    break;
-
-                case 6:
-                    break;
-
-                default:
-                    break;
+                _NumPlayer = NumPlayer;
+                BuildRounds(NumRounds, NumPlayerAtOnce, _Rand);
             }
         }
 
-        
+        public Combination GetRound(int RoundNr)
+        {
+            if (RoundNr >= _Rounds.Count || _NumPlayer == 0 || _Rounds.Count == 0)
+                return null;
+
+            return _Rounds[RoundNr];
+        }
+
+        private void BuildRounds(int NumRounds, int NumPlayerAtOnce, Random Rand)
+        {
+            Combinations Combinations = new Combinations(_NumPlayer, NumPlayerAtOnce, Rand);
+            _Rounds.Add(Combinations.GetNextCombination(null));
+
+            for (int i = 1; i < NumRounds; i++)
+            {
+
+                _Rounds.Add(Combinations.GetNextCombination(GetPlayerDemand(i)));
+            }
+        }
+
+        private List<int> GetPlayerDemand(int RoundIndex)
+        {
+            List<int> NumPlayed = new List<int>(_NumPlayer);
+            for (int i = 0; i < _NumPlayer; i++)
+            {
+                NumPlayed.Add(0);
+            }
+
+            for (int i = 0; i < RoundIndex; i++)
+            {
+                foreach (int PlayerIndex in _Rounds[i].Player)
+                {
+                    NumPlayed[PlayerIndex]++;
+                }
+            }
+
+            int max = 0;
+            foreach (int p in NumPlayed)
+            {
+                if (p > max)
+                    max = p;
+            }
+
+            int num = _Rounds[0].Player.Count;
+            List<int> result = new List<int>();
+            List<int> other = new List<int>();
+            List<int> last = new List<int>();
+
+            for (int i = 0; i < NumPlayed.Count; i++)
+            {
+                if (NumPlayed[i] == 0 || NumPlayed[i] < max)
+                    result.Add(i);
+                else
+                {
+                    if (RoundIndex > 0)
+                    {
+                        if (!_Rounds[RoundIndex - 1].IsAvailable(i))
+                            other.Add(i);
+                        else
+                            last.Add(i);
+                    }
+                    else
+                        last.Add(i);
+
+                }
+            }
+
+            while (result.Count < num && other.Count > 0)
+            {
+                int n = other.Count;
+                int r = _Rand.Next(n);
+                result.Add(other[r]);
+                other.RemoveAt(r);
+            }
+
+            while (result.Count < num)
+            {
+                int n = last.Count;
+                int r = _Rand.Next(n);
+                result.Add(last[r]);
+                last.RemoveAt(r);
+            }
+
+
+            result.Sort();
+            return result;
+        }
     }
 
-    public class ChallengeRound
+    class Combinations
     {
-        private List<int> _ProfileIDs;
+        private List<Combination> _Combs;
+        private Random _Rand;
+        private int _NumPlayer;
+        private int _NumMics;
 
-        public int NumPlayer { get{ return _ProfileIDs.Count; } }
-
-
-        public ChallengeRound()
+        public Combinations(int NumPlayer, int NumMics, Random Rand)
         {
-            _ProfileIDs = new List<int>();
+            _Combs = new List<Combination>();
+            _NumMics = NumMics;
+            _NumPlayer = NumPlayer;
+            _Rand = Rand;            
         }
 
-        public void AddPlayer(int ProfileID)
+        public Combination GetNextCombination(List<int> PlayerNrDemand)
         {
-            _ProfileIDs.Add(ProfileID);
+            if (_Combs.Count == 0)
+                Create();
+
+            Combination combs = new Combination();
+
+            if (_NumPlayer == _NumMics)
+            {
+                return _Combs[0];
+            }
+
+            //filter against PlayerNrDemand
+            List<Combination> combsFiltered = new List<Combination>();
+            if (PlayerNrDemand != null)
+            {
+                for (int i = 0; i < _Combs.Count; i++)
+                {
+                    if (_Combs[i].IsAvailableAll(PlayerNrDemand))
+                        combsFiltered.Add(_Combs[i]);
+                }
+            }
+
+            //1st fallback
+            if (PlayerNrDemand != null && combsFiltered.Count == 0)
+            {
+                for (int i = 0; i < _Combs.Count; i++)
+                {
+                    if (_Combs[i].IsAvailableSomeone(PlayerNrDemand))
+                        combsFiltered.Add(_Combs[i]);
+                }
+            }
+
+            //2nd fallback
+            if (combsFiltered.Count == 0)
+            {
+                for (int i = 0; i < _Combs.Count; i++)
+                {
+                    combsFiltered.Add(_Combs[i]);
+                }
+            }
+
+            int num = combsFiltered.Count;
+            int rand = _Rand.Next(num);
+            Combination c = new Combination();
+            for (int i = 0; i < combsFiltered[rand].Player.Count; i++)
+            {
+                c.Player.Add(combsFiltered[rand].Player[i]);
+            }
+            _Combs.Remove(combsFiltered[rand]);
+
+            return combsFiltered[rand];
         }
 
-        public int GetPlayer(int Nr)
+        private void Create()
         {
-            if (Nr >= _ProfileIDs.Count)
-                return -1;
+            _Combs.Clear();
 
-            return _ProfileIDs[Nr];
+            int num = (int)Math.Pow(2, _NumPlayer);
+
+            for (int i = 1; i <= num; i++)
+            {
+                Combination c = new Combination();
+
+                for (int j = 0; j < _NumPlayer; j++)
+                {
+                    if ((i & (1 << j)) > 0)
+                    {
+                        c.Player.Add(j);
+                    }
+                }
+
+                if (c.Player.Count == _NumMics)
+                    _Combs.Add(c);
+            }
+        }
+    }
+
+    public class Combination
+    {
+        public List<int> Player;
+
+        public Combination()
+        {
+            Player = new List<int>();
+        }
+
+        public bool IsAvailable(int PlayerIndex)
+        {
+            foreach (int p in Player)
+            {
+                if (p == PlayerIndex)
+                    return true;
+            }
+            return false;
+        }
+
+        public bool IsAvailableAll(List<int> PlayerIndices)
+        {
+            bool result = true;
+            foreach (int p in PlayerIndices)
+            {
+                result &= IsAvailable(p);
+            }
+            return result;
+        }
+
+        public bool IsAvailableSomeone(List<int> PlayerIndices)
+        {
+            bool result = false;
+            foreach (int p in PlayerIndices)
+            {
+                result |= IsAvailable(p);
+            }
+            return result;
         }
     }
 }
diff --git a/PartyModeChallenge/PartyModeChallenge.cs b/PartyModeChallenge/PartyModeChallenge.cs
index 76e5dbe7..b4ce5bec 100644
--- a/PartyModeChallenge/PartyModeChallenge.cs
+++ b/PartyModeChallenge/PartyModeChallenge.cs
@@ -81,6 +81,8 @@ namespace Vocaluxe.PartyModes
             public int NumRounds;
             public List<int> ProfileIDs;
 
+            public ChallengeRounds Rounds;
+
             public int CurrentRoundNr;
         }
 
@@ -113,7 +115,7 @@ namespace Vocaluxe.PartyModes
             GameData.NumPlayerAtOnce = 2;
             GameData.NumRounds = 2;
             GameData.CurrentRoundNr = 1;
-            GameData.ProfileIDs = new List<int>();
+            GameData.ProfileIDs = new List<int>();        
         }
 
         public override bool Init()
@@ -230,7 +232,10 @@ namespace Vocaluxe.PartyModes
                 case EStage.Names:
                     _Screens.TryGetValue("PartyScreenChallengeMain", out Screen);
                     if (_Screens != null)
+                    {
+                        GameData.Rounds = new ChallengeRounds(GameData.NumRounds, GameData.NumPlayer, GameData.NumPlayerAtOnce);
                         Screen.DataToScreen(ToScreenMain);
+                    }
                     break;
                 case EStage.Main:
                     AlternativeScreen = EScreens.ScreenSong;