diff --git a/Stars Assistant/Model/Planet.cs b/Stars Assistant/Model/Planet.cs
index b7ab232..08ea465 100644
--- a/Stars Assistant/Model/Planet.cs	
+++ b/Stars Assistant/Model/Planet.cs	
@@ -7,8 +7,6 @@ public class Planet
 {
     #region Persistant and derived propeties
 
-    public const int MinEffectiveValue = 5;
-
     [Key]
     public required string Name { get; set; }
 
@@ -90,94 +88,19 @@ public class Planet
 
     #region Derived Properties
 
-    public static int EffectiveValue(int? value) {
-        if (value == null) return 0;
-        if (value < MinEffectiveValue) return MinEffectiveValue;
-        return (int) value;
-    }
+    // public int EffectiveValue() => EffectiveValue(Value);
 
-    public int EffectiveValue() => EffectiveValue(Value);
+    // public int MaxPopOnPlanet() => MaxPopOnPlanet(Value);
 
-    public static int MaxPopOnPlanet (int? value) {
-        return Services.Game.Player.MaxPopOnPlanet * EffectiveValue(value) / 100;
-    }
+    // public int PopGrowth() => PopGrowth(Population ?? 0, MaxPopOnPlanet(), Value ?? 0);
 
-    public int MaxPopOnPlanet() => MaxPopOnPlanet(Value);
+    // public int MaxFact() => MaxFact(Population ?? 0);
 
-    public int PopGrowth(int currentPop, int maxPop, int value) {
-        // What to do with non player races?
-        if (OwnerId != Services.Game.Player.Name) return 0;
+    // public int MaxMines() => MaxMines(Population ?? 0);
 
-        double popRatio = currentPop / maxPop;
-        int growth = 0;
-        if (value < 0)
-            growth = currentPop * value / 10;
-        else if (popRatio <= 0.25)
-            growth = currentPop * value * (Services.Game.Player.GrowthRatePercent ?? 0) / 100;
-        else if (popRatio <= 1)
-            growth = currentPop * value * (Services.Game.Player.GrowthRatePercent ?? 0) /100 * 16 / 9 * ((int) Math.Pow(1 - popRatio, 2));
-        else
-            growth = (int) (currentPop * (popRatio - 1) * 0.04);
+    // public int ResourcesFromPop() => ResourcesFromPop(Population ?? 0, Value ?? 0);
 
-        return growth / 100 * 100;
-    }
-
-    public int PopGrowth() => PopGrowth(Population ?? 0, MaxPopOnPlanet(), Value ?? 0);
-
-    public int MaxFact(int currentPop) {
-        int effectivePop = Math.Min(currentPop, MaxPopOnPlanet());
-        double tmp = (double) effectivePop / 10000 * Services.Game.Player.FactoryNumberPer10k ?? 0;
-        return (int) tmp;
-    }
-
-    public int MaxFact() => MaxFact(Population ?? 0);
-
-    public int MaxMines(int currentPop) {
-        int effectivePop = Math.Min(currentPop, MaxPopOnPlanet());
-        double tmp = (double) effectivePop / 10000 * Services.Game.Player.MineNumberPer10k ?? 0;
-        return (int) tmp;
-    }
-
-    public int MaxMines() => MaxMines(Population ?? 0);
-
-    public static int ResourcesFromPop(int currentPop, int value) {
-        if (Services.Game.Player.ColonistsPerResource == null
-            || Services.Game.Player.ColonistsPerResource == 0) 
-        {
-            return 0;
-        }
-        
-        int maxPop = MaxPopOnPlanet(value);
-        int popFullEfficiency = 0;
-        int popHalfEfficiency = 0;
-        if (currentPop <= maxPop) {
-            popFullEfficiency = currentPop;
-        }
-        else if (currentPop <= 3 * maxPop) {
-            popFullEfficiency = maxPop;
-            popHalfEfficiency = currentPop - maxPop;
-        }
-        else {
-            popFullEfficiency = maxPop;
-            popHalfEfficiency = 2 * maxPop;
-        }
-        int popEffective = popFullEfficiency + (popHalfEfficiency / 2);
-        return (popEffective / Services.Game.Player.ColonistsPerResource) ?? 0;
-    }
-
-    public int ResourcesFromPop() => ResourcesFromPop(Population ?? 0, Value ?? 0);
-
-    public static int ResourcesFromFact(int currentPop, int factories, int value) {
-        int maxPop = MaxPopOnPlanet(value);
-        int effectivePop = Math.Min(currentPop, maxPop);
-        double tmp = (double) effectivePop / 10000 * Services.Game.Player.FactoryNumberPer10k ?? 0;
-        int maxOperableFactories = (int) tmp;
-        int operableFactories = Math.Min(factories, maxOperableFactories);
-        tmp = (double) operableFactories / 10 * Services.Game.Player.FactoryResPer10 ?? 0;
-        return (int) tmp;
-    }
-
-    public int ResourcesFromFact() => ResourcesFromFact(Population ?? 0, Factories ?? 0, Value ?? 0);
+    // public int ResourcesFromFact() => ResourcesFromFact(Population ?? 0, Factories ?? 0, Value ?? 0);
 
     #endregion
 
diff --git a/Stars Assistant/Model/Race.cs b/Stars Assistant/Model/Race.cs
index 691ce4b..2bdf7b6 100644
--- a/Stars Assistant/Model/Race.cs	
+++ b/Stars Assistant/Model/Race.cs	
@@ -24,9 +24,9 @@ public class Race
 
     public int? PlayerFileId { get; set; }
 
-    public int? ColonistsPerResource { get; set; }
+    public int ColonistsPerResource { get; set; } = 1_000;
 
-    public int? GrowthRatePercent { get; set; }
+    public int GrowthRatePercent { get; set; } = 15;
 
     private PRT _PRT = PRT.Other;
     public PRT PRT { 
@@ -37,8 +37,8 @@ public class Race
         }
     }
 
-    private bool? _hasOBRM;
-    public bool? HasOBRM { 
+    private bool _hasOBRM = false;
+    public bool HasOBRM { 
         get => _hasOBRM; 
         set {
             _hasOBRM = value;
@@ -55,29 +55,29 @@ public class Race
     [NotMapped]
     public int MaxEffectivePopOnGreen { get; private set; }
 
-    private bool? _factoryCost3;
-    public bool? FactoryCost3 { 
+    private bool _factoryCost3 = false;
+    public bool FactoryCost3 { 
         get => _factoryCost3; 
         set {
             _factoryCost3 = value;
-            FactoryGerCost = (_factoryCost3 ?? false) ? 3 : 4;
+            FactoryGerCost = _factoryCost3 ? 3 : 4;
         }
     }
 
     [NotMapped]
     public int FactoryGerCost { get; private set; }
 
-    public int? FactoryNumberPer10k { get; set; }
+    public int FactoryNumberPer10k { get; set; } = 10;
 
-    public int? FactoryResCost { get; set; }
+    public int FactoryResCost { get; set; } = 10;
 
-    public int? FactoryResPer10 { get; set; }
+    public int FactoryResPer10 { get; set; } = 10;
 
-    public int? MineResCost { get; set; }
+    public int MineResCost { get; set; } = 5;
 
-    public int? MineNumberPer10k { get; set; }
+    public int MineNumberPer10k { get; set; } = 10;
 
-    public int? MineMineralsPer10 { get; set; }
+    public int MineMineralsPer10 { get; set; } = 10;
 
     #endregion
 
@@ -101,9 +101,9 @@ public class Race
             PRT.JOAT => 1.2,
             _ => 1,
         };
-        double obrmMod = (HasOBRM ?? false) ? 1.1 : 1.0;
+        double obrmMod = HasOBRM ? 1.1 : 1.0;
         MaxPopOnPlanet = Convert.ToInt32(basePop * prtMod * obrmMod);
-        MaxEffectivePopOnRed = MaxPopOnPlanet * Planet.MinEffectiveValue / 100 * 3;
+        MaxEffectivePopOnRed = MaxPopOnPlanet * Services.GameEngine.MinEffectiveValue / 100 * 3;
         MaxEffectivePopOnGreen = MaxPopOnPlanet * 3;
     }
 
diff --git a/Stars Assistant/Services/Game.cs b/Stars Assistant/Services/Game.cs
index 795aa54..e44edfc 100644
--- a/Stars Assistant/Services/Game.cs	
+++ b/Stars Assistant/Services/Game.cs	
@@ -120,6 +120,7 @@ public class Game
     public void RegisterServicesForGame()
     {
         Locator.CurrentMutable.RegisterConstant(this, typeof(Services.Game));
+        GameEngine.Game = this;
         Locator.CurrentMutable.RegisterConstant(new CSVDataLoader(), typeof(CSVDataLoader));
         Locator.CurrentMutable.Register(() => new StarsDatabase(DatabaseFileName), typeof(StarsDatabase));
 
diff --git a/Stars Assistant/Services/GameEngine.cs b/Stars Assistant/Services/GameEngine.cs
index b6b9fda..cfb9e89 100644
--- a/Stars Assistant/Services/GameEngine.cs	
+++ b/Stars Assistant/Services/GameEngine.cs	
@@ -1,8 +1,162 @@
 using System;
+using Splat;
 
 namespace StarsAssistant.Services;
 
 public class GameEngine
 {
+    /// <summary>
+    /// Helper reference to the Game, populated during service registration for the
+    /// loaded game.
+    /// </summary>
+    // TODO: check for better options here.
+    public static Game Game { get; set; } = null!;
+
+    /// <summary>
+    /// Minimum effective value of a planet for purposes of maximum population etc.
+    /// </summary>
+    public const int MinEffectiveValue = 5;
+
+    /// <summary>
+    /// Normalize a planet value for minimum effetive value.
+    /// </summary>
+    /// <param name="value">Real planet value</param>
+    /// <returns>Effective plante value</returns>
+    public static int EffectivePlanetValue(int value) => (value < MinEffectiveValue) ? MinEffectiveValue : value;
+
+    /// <summary>
+    /// Compute the maximum regular (non-overcrowded) population on a planet for the active player.
+    /// </summary>
+    /// <param name="value">Real planet value</param>
+    /// <returns>effective maximum population</returns>
+    public static int MaxPopOnPlanetForPlayer(int value) => Game.Player.MaxPopOnPlanet * EffectivePlanetValue(value) / 100;
+
+    /// <summary>
+    /// Compute population growth for player planets.
+    /// </summary>
+    /// <param name="currentPop">Current population on planet</param>
+    /// <param name="value">Real planet value</param>
+    /// <returns>population growth per turn</returns>
+    public static int PlanetPopGrowthForPlayer(int currentPop, int value) 
+    {
+        int maxPop = MaxPopOnPlanetForPlayer(value);
+        int growth;
+
+        if (value < 0)
+        {
+            growth = currentPop * value / 10;
+        } 
+        else 
+        {
+            double popRatio = currentPop / maxPop;
+            if (popRatio <= 0.25)
+                growth = currentPop * value * Game.Player.GrowthRatePercent / 100;
+            else if (popRatio <= 1)
+                growth = currentPop * value * Game.Player.GrowthRatePercent /100 * 16 / 9 * ((int) Math.Pow(1 - popRatio, 2));
+            else
+                 growth = (int) (currentPop * (popRatio - 1) * 0.04);
+        }
+
+        // round to nearest 100
+        return growth / 100 * 100;
+    }
+
+    /// <summary>
+    /// Returns the maximum operable factories on a given player planet for a given value.
+    /// </summary>
+    /// <param name="currentPop">Population on planet</param>
+    /// <param name="value">Real planet value</param>
+    /// <returns>Maximum operable factories for currentPop</returns>
+    public static int MaxOperableFactoriesForPlayer(int currentPop, int value)
+    {
+        int effectivePop = Math.Min(currentPop, MaxPopOnPlanetForPlayer(value));
+        double tmp = (double) effectivePop / 10000 * Game.Player.FactoryNumberPer10k;
+        return (int) tmp;
+    }
+
+    /// <summary>
+    /// Maximum buildable factories on a player planet with a given value.
+    /// </summary>
+    /// <param name="value">Real Planet Value</param>
+    /// <returns>Maximum buildable factories</returns>
+    public static int MaxBuildableFactoriesForPlayer(int value)
+    {
+        double tmp = (double) MaxPopOnPlanetForPlayer(value) / 10000 * Game.Player.FactoryNumberPer10k;
+        return (int) tmp;
+    }
+
+    /// <summary>
+    /// Returns the maximum operable mines on a given player planet for a given value.
+    /// </summary>
+    /// <param name="currentPop">Population on planet</param>
+    /// <param name="value">Real planet value</param>
+    /// <returns>Maximum operable mines for currentPop</returns>
+    public static int MaxOperableMinesForPlayer(int currentPop, int value)
+    {
+        int effectivePop = Math.Min(currentPop, MaxPopOnPlanetForPlayer(value));
+        double tmp = (double) effectivePop / 10000 * Game.Player.MineNumberPer10k;
+        return (int) tmp;
+    } 
+
+    /// <summary>
+    /// Maximum buildable factories on a player planet with a given value.
+    /// </summary>
+    /// <param name="value">Real Planet Value</param>
+    /// <returns>Maximum buildable factories</returns>
+    public static int MaxBuildableMinesForPlayer(int value)
+    {
+        double tmp = (double) MaxPopOnPlanetForPlayer(value) / 10000 * Game.Player.MineNumberPer10k;
+        return (int) tmp;
+    }
+
+    /// <summary>
+    /// Ressources produced by population on a player planet with a given value. Takes
+    /// less effective overcrowding pop into account.
+    /// </summary>
+    /// <param name="currentPop">Current planetary population</param>
+    /// <param name="value">Real planet value</param>
+    /// <returns>Resources generated by populationa</returns>
+    public static int ResourcesFromPopForPlayer(int currentPop, int value) 
+    {
+        if (Game.Player.ColonistsPerResource == 0) 
+            return 0;
+        
+        int maxPop = MaxPopOnPlanetForPlayer(value);
+        int popFullEfficiency;
+        int popHalfEfficiency;
+        if (currentPop <= maxPop) {
+            popHalfEfficiency = 0;
+            popFullEfficiency = currentPop;
+        }
+        else if (currentPop <= 3 * maxPop) {
+            popFullEfficiency = maxPop;
+            popHalfEfficiency = currentPop - maxPop;
+        }
+        else {
+            popFullEfficiency = maxPop;
+            popHalfEfficiency = 2 * maxPop;
+        }
+        int popEffective = popFullEfficiency + (popHalfEfficiency / 2);
+        return popEffective / Services.Game.Player.ColonistsPerResource;
+    }
+
+    /// <summary>
+    /// Ressources generated by factories on a player planet for a given value an
+    /// population. Takes maximum operable factories into account.
+    /// </summary>
+    /// <param name="currentPop">Current planetary population</param>
+    /// <param name="factories">Number of factories built</param>
+    /// <param name="value">Real planet value</param>
+    /// <returns>Resources generated by factories</returns>
+    public static int ResourcesFromFactForPlayer(int currentPop, int factories, int value) 
+    {
+        int maxPop = MaxPopOnPlanetForPlayer(value);
+        int effectivePop = Math.Min(currentPop, maxPop);
+        double tmp = (double) effectivePop / 10000 * Game.Player.FactoryNumberPer10k;
+        int maxOperableFactories = (int) tmp;
+        int operableFactories = Math.Min(factories, maxOperableFactories);
+        tmp = (double) operableFactories / 10 * Services.Game.Player.FactoryResPer10;
+        return (int) tmp;
+    }
 
 }
diff --git a/Stars Assistant/ViewModels/PlanetViewModel.cs b/Stars Assistant/ViewModels/PlanetViewModel.cs
index 9ed7cf3..cdd39b2 100644
--- a/Stars Assistant/ViewModels/PlanetViewModel.cs	
+++ b/Stars Assistant/ViewModels/PlanetViewModel.cs	
@@ -38,6 +38,10 @@ public partial class PlanetViewModel : ViewModelBase
 
     public int SurfaceGermanium => Planet.SurfaceGermanium ?? 0;
 
+
+
+    // ### TESTING CODE ###
+
     public static ObservableCollection<PlanetViewModel> LoadAll() 
     {
         using var db = Locator.Current.GetService<StarsDatabase>()!;