diff --git a/SabreTools.Filter/FilterObject.cs b/SabreTools.Filter/FilterObject.cs
new file mode 100644
index 00000000..1478a593
--- /dev/null
+++ b/SabreTools.Filter/FilterObject.cs
@@ -0,0 +1,256 @@
+using System;
+using SabreTools.Models.Internal;
+
+namespace SabreTools.Filter
+{
+    /// <summary>
+    /// Represents a single filtering object
+    /// </summary>
+    public class FilterObject
+    {
+        /// <summary>
+        /// Key name for the filter
+        /// </summary>
+        public string Key { get; init; }
+
+        /// <summary>
+        /// Value to match in the filter
+        /// </summary>
+        public string? Value { get; init; }
+
+        /// <summary>
+        /// Operation on how to match the filter
+        /// </summary>
+        public Operation Operation { get; init; }
+
+        public FilterObject(string keyValue, string? operation)
+        {
+            (string? itemName, string? fieldName) = FilterParser.ParseFilterId(keyValue);
+            if (itemName == null)
+                throw new ArgumentOutOfRangeException(nameof(keyValue));
+
+            this.Key = itemName;
+            this.Value = fieldName;
+            this.Operation = GetOperation(operation);
+        }
+
+        public FilterObject(string keyValue, Operation operation)
+        {
+            (string? itemName, string? fieldName) = FilterParser.ParseFilterId(keyValue);
+            if (itemName == null)
+                throw new ArgumentOutOfRangeException(nameof(keyValue));
+
+            this.Key = itemName;
+            this.Value = fieldName;
+            this.Operation = operation;
+        }
+
+        public FilterObject(string key, string? value, string? operation)
+        {
+            (string? itemName, string? fieldName) = FilterParser.ParseFilterId(key, value);
+            if (itemName == null)
+                throw new ArgumentOutOfRangeException(nameof(fieldName));
+
+            this.Key = itemName;
+            this.Value = fieldName;
+            this.Operation = GetOperation(operation);
+        }
+
+        public FilterObject(string key, string? value, Operation operation)
+        {
+            (string? itemName, string? fieldName) = FilterParser.ParseFilterId(key, value);
+            if (itemName == null)
+                throw new ArgumentOutOfRangeException(nameof(fieldName));
+
+            this.Key = itemName;
+            this.Value = fieldName;
+            this.Operation = operation;
+        }
+
+        /// <summary>
+        /// Derive an operation from the input string, if possible
+        /// </summary>
+        private static Operation GetOperation(string? operation)
+        {
+            return operation?.ToLowerInvariant() switch
+            {
+                "=" => Operation.Equals,
+                "==" => Operation.Equals,
+
+                "!" => Operation.NotEquals,
+                "!=" => Operation.NotEquals,
+
+                ">" => Operation.GreaterThan,
+                ">=" => Operation.GreaterThanOrEqual,
+
+                "<" => Operation.LessThan,
+                "<=" => Operation.LessThanOrEqual,
+
+                _ => Operation.NONE,
+            };
+        }
+
+        #region Matching
+
+        /// <summary>
+        /// Determine if a DictionaryBase object matches the key and value
+        /// </summary>
+        public bool Matches(DictionaryBase dictionaryBase)
+        {
+            return this.Operation switch
+            {
+                Operation.Equals => MatchesEqual(dictionaryBase),
+                Operation.NotEquals => MatchesNotEqual(dictionaryBase),
+                Operation.GreaterThan => MatchesGreaterThan(dictionaryBase),
+                Operation.GreaterThanOrEqual => MatchesGreaterThanOrEqual(dictionaryBase),
+                Operation.LessThan => MatchesLessThan(dictionaryBase),
+                Operation.LessThanOrEqual => MatchesLessThanOrEqual(dictionaryBase),
+                _ => false,
+            };
+        }
+
+        /// <summary>
+        /// Determines if a value matches exactly
+        /// </summary>
+        /// <remarks>TODO: Add regex matching to this method</remarks>
+        private bool MatchesEqual(DictionaryBase dictionaryBase)
+        {
+            if (!dictionaryBase.ContainsKey(this.Key))
+                return this.Value == null;
+
+            string? checkValue = dictionaryBase.ReadString(this.Key);
+            return checkValue == this.Value;
+        }
+
+        /// <summary>
+        /// Determines if a value does not match exactly
+        /// </summary>
+        /// <remarks>TODO: Add regex matching to this method</remarks>
+        private bool MatchesNotEqual(DictionaryBase dictionaryBase)
+        {
+            if (!dictionaryBase.ContainsKey(this.Key))
+                return this.Value != null;
+
+            string? checkValue = dictionaryBase.ReadString(this.Key);
+            return checkValue != this.Value;
+        }
+
+        /// <summary>
+        /// Determines if a value is strictly greater than
+        /// </summary>
+        private bool MatchesGreaterThan(DictionaryBase dictionaryBase)
+        {
+            if (!dictionaryBase.ContainsKey(this.Key))
+                return false;
+
+            long? checkLongValue = dictionaryBase.ReadLong(this.Key);
+            if (checkLongValue != null)
+            {
+                if (!long.TryParse(this.Value, out long matchValue))
+                    return false;
+
+                return checkLongValue > matchValue;
+            }
+
+            double? checkDoubleValue = dictionaryBase.ReadDouble(this.Key);
+            if (checkDoubleValue != null)
+            {
+                if (!double.TryParse(this.Value, out double matchValue))
+                    return false;
+
+                return checkDoubleValue > matchValue;
+            }
+
+            return false;
+        }
+
+        /// <summary>
+        /// Determines if a value is greater than or equal
+        /// </summary>
+        private bool MatchesGreaterThanOrEqual(DictionaryBase dictionaryBase)
+        {
+            if (!dictionaryBase.ContainsKey(this.Key))
+                return false;
+
+            long? checkLongValue = dictionaryBase.ReadLong(this.Key);
+            if (checkLongValue != null)
+            {
+                if (!long.TryParse(this.Value, out long matchValue))
+                    return false;
+
+                return checkLongValue >= matchValue;
+            }
+
+            double? checkDoubleValue = dictionaryBase.ReadDouble(this.Key);
+            if (checkDoubleValue != null)
+            {
+                if (!double.TryParse(this.Value, out double matchValue))
+                    return false;
+
+                return checkDoubleValue >= matchValue;
+            }
+
+            return false;
+        }
+    
+        /// <summary>
+        /// Determines if a value is strictly less than
+        /// </summary>
+        private bool MatchesLessThan(DictionaryBase dictionaryBase)
+        {
+            if (!dictionaryBase.ContainsKey(this.Key))
+                return false;
+
+            long? checkLongValue = dictionaryBase.ReadLong(this.Key);
+            if (checkLongValue != null)
+            {
+                if (!long.TryParse(this.Value, out long matchValue))
+                    return false;
+
+                return checkLongValue < matchValue;
+            }
+
+            double? checkDoubleValue = dictionaryBase.ReadDouble(this.Key);
+            if (checkDoubleValue != null)
+            {
+                if (!double.TryParse(this.Value, out double matchValue))
+                    return false;
+
+                return checkDoubleValue < matchValue;
+            }
+
+            return false;
+        }
+
+        /// <summary>
+        /// Determines if a value is less than or equal
+        /// </summary>
+        private bool MatchesLessThanOrEqual(DictionaryBase dictionaryBase)
+        {
+            if (!dictionaryBase.ContainsKey(this.Key))
+                return false;
+
+            long? checkLongValue = dictionaryBase.ReadLong(this.Key);
+            if (checkLongValue != null)
+            {
+                if (!long.TryParse(this.Value, out long matchValue))
+                    return false;
+
+                return checkLongValue <= matchValue;
+            }
+
+            double? checkDoubleValue = dictionaryBase.ReadDouble(this.Key);
+            if (checkDoubleValue != null)
+            {
+                if (!double.TryParse(this.Value, out double matchValue))
+                    return false;
+
+                return checkDoubleValue <= matchValue;
+            }
+
+            return false;
+        }
+    
+        #endregion
+    }
+}
\ No newline at end of file
diff --git a/SabreTools.Filter/FilterParser.cs b/SabreTools.Filter/FilterParser.cs
index dfb8f493..c6a74a6f 100644
--- a/SabreTools.Filter/FilterParser.cs
+++ b/SabreTools.Filter/FilterParser.cs
@@ -12,38 +12,50 @@ namespace SabreTools.Filter
         /// <summary>
         /// Parse a filter ID string into the item name and field name, if possible
         /// </summary>
-        public static (string?, string?) ParseFilterId(string filterId)
+        public static (string?, string?) ParseFilterId(string itemFieldString)
         {
             // If we don't have a filter ID, we can't do anything
-            if (string.IsNullOrWhiteSpace(filterId))
+            if (string.IsNullOrWhiteSpace(itemFieldString))
                 return (null, null);
 
             // If we only have one part, we can't do anything
-            string[] splitFilter = filterId.Split('.');
+            string[] splitFilter = itemFieldString.Split('.');
             if (splitFilter.Length != 2)
                 return (null, null);
 
+            return ParseFilterId(splitFilter[0], splitFilter[1]);
+        }
+
+        /// <summary>
+        /// Parse a filter ID string into the item name and field name, if possible
+        /// </summary>
+        public static (string?, string?) ParseFilterId(string itemName, string? fieldName)
+        {
+            // If we don't have a filter ID, we can't do anything
+            if (string.IsNullOrWhiteSpace(itemName) || string.IsNullOrWhiteSpace(fieldName))
+                return (null, null);
+
             // Return santized values based on the split ID
-            return splitFilter[0].ToLowerInvariant() switch
+            return itemName.ToLowerInvariant() switch
             {
                 // Header
-                "header" => ParseHeaderFilterId(splitFilter),
+                "header" => ParseHeaderFilterId(fieldName),
 
                 // Machine
-                "game" => ParseMachineFilterId(splitFilter),
-                "machine" => ParseMachineFilterId(splitFilter),
-                "resource" => ParseMachineFilterId(splitFilter),
-                "set" => ParseMachineFilterId(splitFilter),
+                "game" => ParseMachineFilterId(fieldName),
+                "machine" => ParseMachineFilterId(fieldName),
+                "resource" => ParseMachineFilterId(fieldName),
+                "set" => ParseMachineFilterId(fieldName),
 
                 // DatItem
-                _ => ParseDatItemFilterId(splitFilter),
+                _ => ParseDatItemFilterId(itemName, fieldName),
             };
         }
 
         /// <summary>
         /// Parse and validate header fields
         /// </summary>
-        private static (string?, string?) ParseHeaderFilterId(string[] filterId)
+        private static (string?, string?) ParseHeaderFilterId(string fieldName)
         {
             // Get the set of constants
             var constants = GetConstants(typeof(Header));
@@ -51,7 +63,7 @@ namespace SabreTools.Filter
                 return (null, null);
 
             // Get if there's a match to the constant
-            string? constantMatch = constants.FirstOrDefault(c => string.Equals(c, filterId[1], StringComparison.OrdinalIgnoreCase));
+            string? constantMatch = constants.FirstOrDefault(c => string.Equals(c, fieldName, StringComparison.OrdinalIgnoreCase));
             if (constantMatch == null)
                 return (null, null);
 
@@ -62,7 +74,7 @@ namespace SabreTools.Filter
         /// <summary>
         /// Parse and validate machine/game fields
         /// </summary>
-        private static (string?, string?) ParseMachineFilterId(string[] filterId)
+        private static (string?, string?) ParseMachineFilterId(string fieldName)
         {
             // Get the set of constants
             var constants = GetConstants(typeof(Machine));
@@ -70,7 +82,7 @@ namespace SabreTools.Filter
                 return (null, null);
 
             // Get if there's a match to the constant
-            string? constantMatch = constants.FirstOrDefault(c => string.Equals(c, filterId[1], StringComparison.OrdinalIgnoreCase));
+            string? constantMatch = constants.FirstOrDefault(c => string.Equals(c, fieldName, StringComparison.OrdinalIgnoreCase));
             if (constantMatch == null)
                 return (null, null);
 
@@ -81,10 +93,10 @@ namespace SabreTools.Filter
         /// <summary>
         /// Parse and validate item fields
         /// </summary>
-        private static (string?, string?) ParseDatItemFilterId(string[] filterId)
+        private static (string?, string?) ParseDatItemFilterId(string itemName, string fieldName)
         {
             // Get the correct item type
-            var itemType = GetDatItemType(filterId[0].ToLowerInvariant());
+            var itemType = GetDatItemType(itemName.ToLowerInvariant());
             if (itemType == null)
                 return (null, null);
 
@@ -94,12 +106,12 @@ namespace SabreTools.Filter
                 return (null, null);
 
             // Get if there's a match to the constant
-            string? constantMatch = constants.FirstOrDefault(c => string.Equals(c, filterId[1], StringComparison.OrdinalIgnoreCase));
+            string? constantMatch = constants.FirstOrDefault(c => string.Equals(c, fieldName, StringComparison.OrdinalIgnoreCase));
             if (constantMatch == null)
                 return (null, null);
 
             // Return the sanitized ID
-            return (filterId[0].ToLowerInvariant(), constantMatch);
+            return (itemName.ToLowerInvariant(), constantMatch);
         }
 
         /// <summary>
diff --git a/SabreTools.Filter/Operation.cs b/SabreTools.Filter/Operation.cs
new file mode 100644
index 00000000..d9adaed5
--- /dev/null
+++ b/SabreTools.Filter/Operation.cs
@@ -0,0 +1,20 @@
+namespace SabreTools.Filter
+{
+    /// <summary>
+    /// Determines what operation is being done
+    /// </summary>
+    public enum Operation
+    {
+        /// <summary>
+        /// Default value, does nothing
+        /// </summary>
+        NONE,
+        
+        Equals,
+        NotEquals,
+        GreaterThan,
+        GreaterThanOrEqual,
+        LessThan,
+        LessThanOrEqual,
+    }
+}
\ No newline at end of file
diff --git a/SabreTools.Models/Internal/DictionaryBase.cs b/SabreTools.Models/Internal/DictionaryBase.cs
index b7c445d6..44f677b6 100644
--- a/SabreTools.Models/Internal/DictionaryBase.cs
+++ b/SabreTools.Models/Internal/DictionaryBase.cs
@@ -12,9 +12,7 @@ namespace SabreTools.Models.Internal
         /// </summary>
         public T? Read<T>(string key)
         {
-            if (string.IsNullOrWhiteSpace(key))
-                return default;
-            if (!ContainsKey(key))
+            if (!ValidateKey(key))
                 return default;
             return (T?)this[key];
         }
@@ -24,6 +22,9 @@ namespace SabreTools.Models.Internal
         /// </summary>
         public bool? ReadBool(string key)
         {
+            if (!ValidateKey(key))
+                return null;
+
             bool? asBool = Read<bool>(key);
             if (asBool != null)
                 return asBool;
@@ -44,6 +45,9 @@ namespace SabreTools.Models.Internal
         /// </summary>
         public double? ReadDouble(string key)
         {
+            if (!ValidateKey(key))
+                return null;
+
             double? asDouble = Read<double>(key);
             if (asDouble != null)
                 return asDouble;
@@ -60,6 +64,9 @@ namespace SabreTools.Models.Internal
         /// </summary>
         public long? ReadLong(string key)
         {
+            if (!ValidateKey(key))
+                return null;
+
             long? asLong = Read<long>(key);
             if (asLong != null)
                 return asLong;
@@ -76,6 +83,9 @@ namespace SabreTools.Models.Internal
         /// </summary>
         public string? ReadString(string key)
         {
+            if (!ValidateKey(key))
+                return null;
+
             string? asString = Read<string>(key);
             if (asString != null)
                 return asString;
@@ -84,7 +94,7 @@ namespace SabreTools.Models.Internal
             if (asArray != null)
                 return string.Join(',', asArray);
 
-            return null;
+            return this[key]!.ToString();
         }
 
         /// <summary>
@@ -92,6 +102,9 @@ namespace SabreTools.Models.Internal
         /// </summary>
         public string[]? ReadStringArray(string key)
         {
+            if (!ValidateKey(key))
+                return null;
+
             string[]? asArray = Read<string[]>(key);
             if (asArray != null)
                 return asArray;
@@ -100,7 +113,26 @@ namespace SabreTools.Models.Internal
             if (asString != null)
                 return new string[] { asString };
 
+            asString = this[key]!.ToString();
+            if (asString != null)
+                return new string[] { asString };
+
             return null;
         }
+
+        /// <summary>
+        /// Check if a key is valid
+        /// </summary>
+        private bool ValidateKey(string key)
+        {
+            if (string.IsNullOrWhiteSpace(key))
+                return false;
+            else if (!ContainsKey(key))
+                return false;
+            else if (this[key] == null)
+                return false;
+
+            return true;
+        }
     }
 }
\ No newline at end of file