--- a/API/Objects/Requirement/RequiresNoMoreThanNOfUnitTypeRequirement.cs	Sun May 01 14:45:56 2011 +0000
+++ b/API/Objects/Requirement/RequiresNoMoreThanNOfUnitTypeRequirement.cs	Sun May 01 15:39:05 2011 +0000
@@ -4,6 +4,7 @@
 using System;
 using IBBoard.WarFoundry.API.Objects;
 using System.Collections.Generic;
+using System.Text;
 
 namespace IBBoard.WarFoundry.API.Objects.Requirement
 {
@@ -16,6 +17,7 @@
 
 		public RequiresNoMoreThanNOfUnitTypeRequirement(params UnitType[] limitedUnitTypes)
 		{
+			FailureStringPrefix = "Army cannot contain more than: ";
 			limitedTypes = new List<UnitCountRequirementData>();
 
 			foreach (UnitType unitType in limitedUnitTypes)
@@ -116,17 +118,34 @@
 		{
 			RequiresNoMoreThanNOfUnitTypeRequirement other = (RequiresNoMoreThanNOfUnitTypeRequirement)obj;
 			return Collections.Collections.AreEqual(limitedTypes, other.limitedTypes);
-		}
-
-		public override int GetHashCode()
-		{
-			return base.GetHashCode ();
 		}
 
+		protected string FailureStringPrefix { get; set; }
+
 		protected override string GetValidationFailedMessage (Army army)
 		{
-			string message = "";
-			return message;
+			StringBuilder sb = new StringBuilder();
+			sb.Append(FailureStringPrefix);
+			sb.Append(String.Join("; ", GetFailedRequirements(army).ToArray()));
+			sb.Append(".");
+			return sb.ToString();
+		}
+
+		private List<string> GetFailedRequirements(Army army)
+		{
+			List<string> failures = new List<string>();
+
+			foreach (UnitCountRequirementData requirement in limitedTypes)
+			{
+				int unitCount = army.GetUnitTypeCount(requirement.UnitType);
+
+				if (unitCount > requirement.Count)
+				{
+					failures.Add(requirement.Count + " × " + requirement.UnitType.Name + " (have " + unitCount + ")");
+				}
+			}
+
+			return failures;
 		}
 	}
 }

--- a/API/Objects/Requirement/UnitRequiresNoMoreThanNOfUnitTypeRequirement.cs	Sun May 01 14:45:56 2011 +0000
+++ b/API/Objects/Requirement/UnitRequiresNoMoreThanNOfUnitTypeRequirement.cs	Sun May 01 15:39:05 2011 +0000
@@ -1,58 +1,59 @@
-// This file (UnitRequiresAtLeastNUnitsRequirement.cs) is a part of the IBBoard.WarFoundry.API project and is copyright 2011 IBBoard
-// 
-// The file and the library/program it is in are licensed and distributed, without warranty, under the GNU Affero GPL license, either version 3 of the License or (at your option) any later version. Please see COPYING for more information and the full license.
-using System;
-using System.Collections.Generic;
-using IBBoard.WarFoundry.API.Objects;
-
-namespace IBBoard.WarFoundry.API.Objects.Requirement
-{
-	/// <summary>
-	/// A requirement where a UnitType can only be taken if there are no more than N units of one or more unit in an army.
-	/// </summary>
-	public class UnitRequiresNoMoreThanNOfUnitTypeRequirement : RequiresNoMoreThanNOfUnitTypeRequirement
-	{
-		private UnitType requirementOnType;
-
-		public UnitRequiresNoMoreThanNOfUnitTypeRequirement(UnitType requirementOn) : base()
-		{
-			requirementOnType = requirementOn;
-		}
-
-		/// <summary>
-		/// Checks whether the supplied WarFoundryObject can be added to the supplied army.
-		/// </summary>
-		/// <returns>
-		/// A <code>Validation</code> enum to show the result of the validation
-		/// </returns>
-		/// <param name='wfObject'>
-		/// The object that we want to add. This may be involved in the check, or it may not affect the evaluation of the requirement
-		/// </param>
-		/// <param name='toArmy'>
-		/// The army to add the object to.
-		/// </param>
-		public override Validation AllowsAdding(WarFoundryObject wfObject, Army toArmy)
-		{
-			return IsApplicable(wfObject, toArmy) ? base.AllowsAdding(wfObject, toArmy) : Validation.NotApplicable;
-		}
-
-
-		private bool IsApplicable(WarFoundryObject toObject, Army toArmy)
-		{
-			return IsApplicable(toArmy) || IsApplicable(toObject);
-		}
-
-
-		private bool IsApplicable(Army toArmy)
-		{
-			return toArmy.GetUnitTypeCount(requirementOnType) > 0;
-		}
-
-
-		private bool IsApplicable(WarFoundryObject toObject)
-		{
-			return requirementOnType.Equals(toObject) || (toObject is Unit && requirementOnType.Equals(((Unit)toObject).UnitType));
-		}
-	}
-}
-
+// This file (UnitRequiresAtLeastNUnitsRequirement.cs) is a part of the IBBoard.WarFoundry.API project and is copyright 2011 IBBoard
+// 
+// The file and the library/program it is in are licensed and distributed, without warranty, under the GNU Affero GPL license, either version 3 of the License or (at your option) any later version. Please see COPYING for more information and the full license.
+using System;
+using System.Collections.Generic;
+using IBBoard.WarFoundry.API.Objects;
+
+namespace IBBoard.WarFoundry.API.Objects.Requirement
+{
+	/// <summary>
+	/// A requirement where a UnitType can only be taken if there are no more than N units of one or more unit in an army.
+	/// </summary>
+	public class UnitRequiresNoMoreThanNOfUnitTypeRequirement : RequiresNoMoreThanNOfUnitTypeRequirement
+	{
+		private UnitType requirementOnType;
+
+		public UnitRequiresNoMoreThanNOfUnitTypeRequirement(UnitType requirementOn) : base()
+		{
+			requirementOnType = requirementOn;
+			FailureStringPrefix = "Army contains " + requirementOn.Name + " and so cannot contain more than: ";
+		}
+
+		/// <summary>
+		/// Checks whether the supplied WarFoundryObject can be added to the supplied army.
+		/// </summary>
+		/// <returns>
+		/// A <code>Validation</code> enum to show the result of the validation
+		/// </returns>
+		/// <param name='wfObject'>
+		/// The object that we want to add. This may be involved in the check, or it may not affect the evaluation of the requirement
+		/// </param>
+		/// <param name='toArmy'>
+		/// The army to add the object to.
+		/// </param>
+		public override Validation AllowsAdding(WarFoundryObject wfObject, Army toArmy)
+		{
+			return IsApplicable(wfObject, toArmy) ? base.AllowsAdding(wfObject, toArmy) : Validation.NotApplicable;
+		}
+
+
+		private bool IsApplicable(WarFoundryObject toObject, Army toArmy)
+		{
+			return IsApplicable(toArmy) || IsApplicable(toObject);
+		}
+
+
+		private bool IsApplicable(Army toArmy)
+		{
+			return toArmy.GetUnitTypeCount(requirementOnType) > 0;
+		}
+
+
+		private bool IsApplicable(WarFoundryObject toObject)
+		{
+			return requirementOnType.Equals(toObject) || (toObject is Unit && requirementOnType.Equals(((Unit)toObject).UnitType));
+		}
+	}
+}
+