diff --git a/MultiversalDiplomacy/Model/OrderSet.cs b/MultiversalDiplomacy/Model/OrderSet.cs
new file mode 100644
index 0000000..961caa9
--- /dev/null
+++ b/MultiversalDiplomacy/Model/OrderSet.cs
@@ -0,0 +1,28 @@
+namespace MultiversalDiplomacy.Model;
+
+/// <summary>
+/// A list of unit orders submitted by a power.
+/// </summary>
+public class OrderSet
+{
+    /// <summary>
+    /// The raw text of the submitted orders, including the name of the submitting power.
+    /// </summary>
+    public string Text { get; }
+
+    /// <summary>
+    /// Whether the order set has already been adjudicated.
+    /// </summary>
+    public bool Adjudicated { get; }
+
+    /// <summary>
+    /// UTC timestamp at which the order set was submitted
+    /// </summary>
+    public DateTime SubmittedAt { get; }
+
+    public OrderSet(string text)
+    {
+        Text = text;
+        SubmittedAt = DateTime.UtcNow;
+    }
+}
\ No newline at end of file
diff --git a/MultiversalDiplomacy/Model/World.cs b/MultiversalDiplomacy/Model/World.cs
index 799933e..0d683b2 100644
--- a/MultiversalDiplomacy/Model/World.cs
+++ b/MultiversalDiplomacy/Model/World.cs
@@ -44,6 +44,11 @@ public class World
     /// </summary>
     public ReadOnlyDictionary<Season, OrderHistory> OrderHistory { get; }
 
+    /// <summary>
+    /// Submitted order sets.
+    /// </summary>
+    public ReadOnlyCollection<OrderSet> OrderSets { get; }
+
     /// <summary>
     /// Immutable game options.
     /// </summary>
@@ -60,6 +65,7 @@ public class World
         ReadOnlyCollection<Unit> units,
         ReadOnlyCollection<RetreatingUnit> retreatingUnits,
         ReadOnlyDictionary<Season, OrderHistory> orderHistory,
+        ReadOnlyCollection<OrderSet> orderSets,
         Options options)
     {
         this.Provinces = provinces;
@@ -69,6 +75,7 @@ public class World
         this.Units = units;
         this.RetreatingUnits = retreatingUnits;
         this.OrderHistory = orderHistory;
+        this.OrderSets = orderSets;
         this.Options = options;
     }
 
@@ -83,6 +90,7 @@ public class World
         ReadOnlyCollection<Unit>? units = null,
         ReadOnlyCollection<RetreatingUnit>? retreatingUnits = null,
         ReadOnlyDictionary<Season, OrderHistory>? orderHistory = null,
+        ReadOnlyCollection<OrderSet>? orderSets = null,
         Options? options = null)
         : this(
             provinces ?? previous.Provinces,
@@ -92,6 +100,7 @@ public class World
             units ?? previous.Units,
             retreatingUnits ?? previous.RetreatingUnits,
             orderHistory ?? previous.OrderHistory,
+            orderSets ?? previous.OrderSets,
             options ?? previous.Options)
     {
     }
@@ -110,6 +119,7 @@ public class World
             new(new List<Unit>()),
             new(new List<RetreatingUnit>()),
             new(new Dictionary<Season, OrderHistory>()),
+            new(new List<OrderSet>()),
             new Options());
     }
 
@@ -123,7 +133,8 @@ public class World
         IEnumerable<Season>? seasons = null,
         IEnumerable<Unit>? units = null,
         IEnumerable<RetreatingUnit>? retreats = null,
-        IEnumerable<KeyValuePair<Season, OrderHistory>>? orders = null)
+        IEnumerable<KeyValuePair<Season, OrderHistory>>? orders = null,
+        IEnumerable<OrderSet>? orderSets = null)
         => new World(
             previous: this,
             seasons: seasons == null
@@ -137,7 +148,10 @@ public class World
                 : new(retreats.ToList()),
             orderHistory: orders == null
                 ? this.OrderHistory
-                : new(orders.ToDictionary(kvp => kvp.Key, kvp => kvp.Value)));
+                : new(orders.ToDictionary(kvp => kvp.Key, kvp => kvp.Value)),
+            orderSets: orderSets == null
+                ? this.OrderSets
+                : new(orderSets.ToList()));
 
     /// <summary>
     /// Create a new world with new units created from unit specs. Units specs are in the format