diff --git a/MultiversalDiplomacy/Script/ReplScriptHandler.cs b/MultiversalDiplomacy/Script/ReplScriptHandler.cs
index 37d2622..16726a7 100644
--- a/MultiversalDiplomacy/Script/ReplScriptHandler.cs
+++ b/MultiversalDiplomacy/Script/ReplScriptHandler.cs
@@ -32,21 +32,21 @@ public class ReplScriptHandler : IScriptHandler
 
             case "new" when args.Length == 1:
                 Console.WriteLine("usage:");
-                Console.WriteLine("  new blank: standard map, no units");
+                Console.WriteLine("  new custom: standard map, declare units");
                 Console.WriteLine("  new standard: standard map, standard units");
                 break;
 
-            case "new" when args[1] == "blank":
+            case "new" when args[1] == "custom":
                 var world = MultiversalDiplomacy.Model.World.WithStandardMap();
-                var handler = new GameScriptHandler(world);
+                var setupHandler = new SetupScriptHandler(world);
                 Console.WriteLine("Created an empty game");
-                return handler;
+                return setupHandler;
 
             case "new" when args[1] == "standard":
                 world = GameController.InitializeWorld();
-                handler = new GameScriptHandler(world);
+                var gameHandler = new GameScriptHandler(world);
                 Console.WriteLine("Created a standard game");
-                return handler;
+                return gameHandler;
 
             default:
                 Console.WriteLine("Unrecognized command");
diff --git a/MultiversalDiplomacy/Script/SetupScriptHandler.cs b/MultiversalDiplomacy/Script/SetupScriptHandler.cs
new file mode 100644
index 0000000..f2c73e8
--- /dev/null
+++ b/MultiversalDiplomacy/Script/SetupScriptHandler.cs
@@ -0,0 +1,135 @@
+using MultiversalDiplomacy.Model;
+
+namespace MultiversalDiplomacy.Script;
+
+/// <summary>
+/// A script handler for interacting with a loaded game.
+/// </summary>
+public class SetupScriptHandler : IScriptHandler
+{
+    public SetupScriptHandler(World world)
+    {
+        World = world;
+    }
+
+    public string Prompt => "5dp> ";
+
+    public World World { get; set; }
+
+    public IScriptHandler? HandleInput(string input)
+    {
+        var args = input.Split(' ', StringSplitOptions.RemoveEmptyEntries);
+        if (args.Length == 0)
+        {
+            return new GameScriptHandler(World);
+        }
+
+        var command = args[0];
+        switch (command)
+        {
+            case "help":
+            case "?":
+                Console.WriteLine("commands:");
+                Console.WriteLine("  unit: add a unit to the map");
+                Console.WriteLine("  list: list things in a game category");
+                Console.WriteLine("  enter a blank line to complete setup");
+                break;
+
+            case "list" when args.Length == 1:
+                Console.WriteLine("usage:");
+                Console.WriteLine("  list powers: the powers in the game");
+                Console.WriteLine("  list units: units created so far");
+                break;
+
+            case "list" when args[1] == "powers":
+                Console.WriteLine("Powers:");
+                foreach (Power power in World.Powers)
+                {
+                    Console.WriteLine($"  {power.Name}");
+                }
+                break;
+
+            case "list" when args[1] == "units":
+                Console.WriteLine("Units:");
+                foreach (Unit unit in World.Units)
+                {
+                    Console.WriteLine($"  {unit}");
+                }
+                break;
+
+            case "unit" when args.Length < 4:
+                Console.WriteLine("usage: unit [power] [type] [province]");
+                break;
+
+            case "unit":
+                ParseUnit(args);
+                break;
+
+            default:
+                Console.WriteLine("Unrecognized command");
+                break;
+        }
+
+        return this;
+    }
+
+    private void ParseUnit(string[] args)
+    {
+        // Parse the power name by substring matching.
+        string powerArg = args[1].ToLower();
+        var matchingPowers = World.Powers.Where(p => p.Name.ToLower().StartsWith(powerArg));
+        if (matchingPowers.Count() < 1)
+        {
+            Console.WriteLine($"No power named \"{args[1]}\"");
+            return;
+        }
+        if (matchingPowers.Count() > 1)
+        {
+            Console.WriteLine($"Ambiguous power \"{args[1]}\"");
+            return;
+        }
+        Power power = matchingPowers.First();
+
+        // Parse the unit type by substring matching.
+        string typeArg = args[2].ToLower();
+        var matchingTypes = Enum.GetNames<UnitType>().Where(t => t.ToLower().StartsWith(typeArg));
+        if (matchingTypes.Count() < 1)
+        {
+            Console.WriteLine($"No unit type \"{args[2]}\"");
+            return;
+        }
+        if (matchingTypes.Count() > 1)
+        {
+            Console.WriteLine($"Ambiguous unit type \"{args[2]}\"");
+            return;
+        }
+        UnitType type = (UnitType)Enum.Parse(typeof(UnitType), matchingTypes.First());
+
+        // Parse the province by matching the province name or one of its abbreviations,
+        // allowing location specifications separated by a forward slash, e.g. spa/nc.
+        string provinceArg = args[3].ToLower();
+        var matchingProvs = World.Provinces.Where(pr
+            => pr.Abbreviations.Any(abv => abv.ToLower() == provinceArg)
+            || pr.Name.ToLower() == provinceArg);
+        if (matchingProvs.Count() < 1)
+        {
+            Console.WriteLine($"No province matches \"{args[3]}\"");
+            return;
+        }
+        if (matchingTypes.Count() > 1)
+        {
+            Console.WriteLine($"Ambiguous province \"{args[3]}\"");
+            return;
+        }
+        // TODO: this does not support multi-location provinces correctly
+        Province province = matchingProvs.First();
+        Location location = province.Locations.First(loc
+            => type == UnitType.Army && loc.Type == LocationType.Land
+            || type == UnitType.Fleet && loc.Type == LocationType.Water);
+
+        Unit unit = Unit.Build(location, World.RootSeason, power, type);
+        World = World.Update(units: World.Units.Append(unit));
+
+        Console.WriteLine($"Created unit {unit}");
+    }
+}
\ No newline at end of file