diff --git a/MultiversalDiplomacy/Model/World.cs b/MultiversalDiplomacy/Model/World.cs
index 965bace..80bc62b 100644
--- a/MultiversalDiplomacy/Model/World.cs
+++ b/MultiversalDiplomacy/Model/World.cs
@@ -32,7 +32,7 @@ public class World
     /// <summary>
     /// The first season of the game.
     /// </summary>
-    public Season RootSeason { get; }
+    public Season RootSeason => GetSeason("a", 0);
 
     /// <summary>
     /// All units in the multiverse.
@@ -60,7 +60,6 @@ public class World
     private World(
         Map map,
         ReadOnlyCollection<Season> seasons,
-        Season rootSeason,
         ReadOnlyCollection<Unit> units,
         ReadOnlyCollection<RetreatingUnit> retreatingUnits,
         ReadOnlyDictionary<Season, OrderHistory> orderHistory,
@@ -68,7 +67,6 @@ public class World
     {
         this.Map = map;
         this.Seasons = seasons;
-        this.RootSeason = rootSeason;
         this.Units = units;
         this.RetreatingUnits = retreatingUnits;
         this.OrderHistory = orderHistory;
@@ -88,7 +86,6 @@ public class World
         : this(
             previous.Map,
             seasons ?? previous.Seasons,
-            previous.RootSeason,  // Can't change the root season
             units ?? previous.Units,
             retreatingUnits ?? previous.RetreatingUnits,
             orderHistory ?? previous.OrderHistory,
@@ -101,13 +98,11 @@ public class World
     /// </summary>
     public static World WithMap(Map map)
     {
-        Season root = Season.MakeRoot();
         return new World(
             map,
-            new(new List<Season> { root }),
-            root,
-            new(new List<Unit>()),
-            new(new List<RetreatingUnit>()),
+            new([Season.MakeRoot()]),
+            new([]),
+            new([]),
             new(new Dictionary<Season, OrderHistory>()),
             new Options());
     }
@@ -123,7 +118,7 @@ public class World
         IEnumerable<Unit>? units = null,
         IEnumerable<RetreatingUnit>? retreats = null,
         IEnumerable<KeyValuePair<Season, OrderHistory>>? orders = null)
-        => new World(
+        => new(
             previous: this,
             seasons: seasons == null
                 ? this.Seasons