diff --git a/Advanced Software Engineering/Advanced Software Engineering Tests/CommandTester.cs b/Advanced Software Engineering/Advanced Software Engineering Tests/CommandTester.cs
index 98f4862..7d7cf02 100644
--- a/Advanced Software Engineering/Advanced Software Engineering Tests/CommandTester.cs	
+++ b/Advanced Software Engineering/Advanced Software Engineering Tests/CommandTester.cs	
@@ -12,7 +12,7 @@ namespace Advanced_Software_Engineering_Tests {
     /// </summary>
     [TestClass]
     public class CommandTester {
-        private Random rand = new Random();
+        private readonly Random rand = new Random();
 
         /// <summary>
         /// Automatically tests:
diff --git a/Advanced Software Engineering/Advanced Software Engineering Tests/SettingsAndHelperFunctionsTester.cs b/Advanced Software Engineering/Advanced Software Engineering Tests/SettingsAndHelperFunctionsTester.cs
index a3b8f35..837ebf6 100644
--- a/Advanced Software Engineering/Advanced Software Engineering Tests/SettingsAndHelperFunctionsTester.cs	
+++ b/Advanced Software Engineering/Advanced Software Engineering Tests/SettingsAndHelperFunctionsTester.cs	
@@ -11,8 +11,8 @@ namespace Advanced_Software_Engineering_Tests {
     /// </summary>
     [TestClass]
     public class SettingsAndHelperFunctionsTester {
-        private string alphabet = "abcdefghijklmnopqrstuvwxzy";
-        private Random rand = new Random();
+        private readonly string alphabet = "abcdefghijklmnopqrstuvwxzy";
+        private readonly Random rand = new Random();
 
         /// <summary>
         /// Random strip spaces test
diff --git a/Advanced Software Engineering/Advanced Software Engineering/Verbs/DrawingVerbs/Circle.cs b/Advanced Software Engineering/Advanced Software Engineering/Verbs/DrawingVerbs/Circle.cs
index 843ae9f..e6449e9 100644
--- a/Advanced Software Engineering/Advanced Software Engineering/Verbs/DrawingVerbs/Circle.cs	
+++ b/Advanced Software Engineering/Advanced Software Engineering/Verbs/DrawingVerbs/Circle.cs	
@@ -5,7 +5,7 @@
     /// </summary>
     public class Circle : IVerb {
         private readonly Drawer drawer;
-        private double scale;
+        private readonly double scale;
 
         /// <summary>
         /// Circle constructor creates the Circle IVerb.
diff --git a/Advanced Software Engineering/Advanced Software Engineering/Verbs/DrawingVerbs/Clear.cs b/Advanced Software Engineering/Advanced Software Engineering/Verbs/DrawingVerbs/Clear.cs
index 3371010..26155d3 100644
--- a/Advanced Software Engineering/Advanced Software Engineering/Verbs/DrawingVerbs/Clear.cs	
+++ b/Advanced Software Engineering/Advanced Software Engineering/Verbs/DrawingVerbs/Clear.cs	
@@ -4,7 +4,7 @@
     /// The Clear IVerb class.
     /// </summary>
     public class Clear : IVerb {
-        private Drawer drawer;
+        private readonly Drawer drawer;
 
         /// <summary>
         /// Create the clear IVerb
diff --git a/Advanced Software Engineering/Advanced Software Engineering/Verbs/DrawingVerbs/Fill.cs b/Advanced Software Engineering/Advanced Software Engineering/Verbs/DrawingVerbs/Fill.cs
index 969a588..f446387 100644
--- a/Advanced Software Engineering/Advanced Software Engineering/Verbs/DrawingVerbs/Fill.cs	
+++ b/Advanced Software Engineering/Advanced Software Engineering/Verbs/DrawingVerbs/Fill.cs	
@@ -4,8 +4,8 @@
     /// Fill IVerb class
     /// </summary>
     public class Fill : IVerb {
-        private Drawer drawer;
-        private bool enable;
+        private readonly Drawer drawer;
+        private readonly bool enable;
 
         /// <summary>
         /// Fill enables or disables the fill insider drawer
diff --git a/Advanced Software Engineering/Advanced Software Engineering/Verbs/DrawingVerbs/FillColor.cs b/Advanced Software Engineering/Advanced Software Engineering/Verbs/DrawingVerbs/FillColor.cs
index 48d06ba..6b0d61b 100644
--- a/Advanced Software Engineering/Advanced Software Engineering/Verbs/DrawingVerbs/FillColor.cs	
+++ b/Advanced Software Engineering/Advanced Software Engineering/Verbs/DrawingVerbs/FillColor.cs	
@@ -6,8 +6,8 @@ namespace Advanced_Software_Engineering.Verbs.DrawingVerbs {
     /// The FillColor IVerb class
     /// </summary>
     public class FillColor : IVerb {
-        private Drawer drawer;
-        private Color color;
+        private readonly Drawer drawer;
+        private readonly Color color;
 
         /// <summary>
         /// Create the FillColor instance
diff --git a/Advanced Software Engineering/Advanced Software Engineering/Verbs/DrawingVerbs/MoveTo.cs b/Advanced Software Engineering/Advanced Software Engineering/Verbs/DrawingVerbs/MoveTo.cs
index 6794d1a..82cdf07 100644
--- a/Advanced Software Engineering/Advanced Software Engineering/Verbs/DrawingVerbs/MoveTo.cs	
+++ b/Advanced Software Engineering/Advanced Software Engineering/Verbs/DrawingVerbs/MoveTo.cs	
@@ -6,8 +6,8 @@ namespace Advanced_Software_Engineering.Verbs.DrawingVerbs {
     /// MoveTo IVerb class
     /// </summary>
     public class MoveTo : IVerb {
-        private Drawer drawer;
-        private Point moveToPoint;
+        private readonly Drawer drawer;
+        private readonly Point moveToPoint;
 
         /// <summary>
         /// Creates a MoveTo instance
diff --git a/Advanced Software Engineering/Advanced Software Engineering/Verbs/DrawingVerbs/PenColor.cs b/Advanced Software Engineering/Advanced Software Engineering/Verbs/DrawingVerbs/PenColor.cs
index bed68d3..777a488 100644
--- a/Advanced Software Engineering/Advanced Software Engineering/Verbs/DrawingVerbs/PenColor.cs	
+++ b/Advanced Software Engineering/Advanced Software Engineering/Verbs/DrawingVerbs/PenColor.cs	
@@ -6,8 +6,8 @@ namespace Advanced_Software_Engineering.Verbs.DrawingVerbs {
     /// The PenColor IVerb class
     /// </summary>
     public class PenColor : IVerb {
-        private Drawer drawer;
-        private Color color;
+        private readonly Drawer drawer;
+        private readonly Color color;
 
         /// <summary>
         /// Creates a PenColor instance
diff --git a/Advanced Software Engineering/Advanced Software Engineering/Verbs/DrawingVerbs/Quadrilateral.cs b/Advanced Software Engineering/Advanced Software Engineering/Verbs/DrawingVerbs/Quadrilateral.cs
index 9a46414..d37aa87 100644
--- a/Advanced Software Engineering/Advanced Software Engineering/Verbs/DrawingVerbs/Quadrilateral.cs	
+++ b/Advanced Software Engineering/Advanced Software Engineering/Verbs/DrawingVerbs/Quadrilateral.cs	
@@ -6,7 +6,7 @@ namespace Advanced_Software_Engineering.Verbs.DrawingVerbs {
     /// The Quadrilateral IVerb class
     /// </summary>
     public class Quadrilateral : IVerb {
-        private IVerb IVerb;
+        private readonly IVerb IVerb;
 
         /// <summary>
         /// Creates a Quadrilateral instances
diff --git a/Advanced Software Engineering/Advanced Software Engineering/Verbs/DrawingVerbs/Rectangle.cs b/Advanced Software Engineering/Advanced Software Engineering/Verbs/DrawingVerbs/Rectangle.cs
index 8b72420..464b29d 100644
--- a/Advanced Software Engineering/Advanced Software Engineering/Verbs/DrawingVerbs/Rectangle.cs	
+++ b/Advanced Software Engineering/Advanced Software Engineering/Verbs/DrawingVerbs/Rectangle.cs	
@@ -11,11 +11,11 @@ namespace Advanced_Software_Engineering.Verbs.DrawingVerbs {
     /// Correct
     /// </todo>
     public class Rectangle : IVerb {
-        private Drawer drawer;
-        private PointF[] points;
+        private readonly Drawer drawer;
+        private readonly PointF[] points;
 
-        private double width;
-        private double height;
+        private  readonly double width;
+        private readonly double height;
 
         /// <summary>
         /// Create a rectangle instance. Makes sure that
diff --git a/Advanced Software Engineering/Advanced Software Engineering/Verbs/DrawingVerbs/ResetPen.cs b/Advanced Software Engineering/Advanced Software Engineering/Verbs/DrawingVerbs/ResetPen.cs
index e280878..d3119b8 100644
--- a/Advanced Software Engineering/Advanced Software Engineering/Verbs/DrawingVerbs/ResetPen.cs	
+++ b/Advanced Software Engineering/Advanced Software Engineering/Verbs/DrawingVerbs/ResetPen.cs	
@@ -4,7 +4,7 @@
     /// Setsets the pen to the initial position.
     /// </summary>
     public class ResetPen : IVerb {
-        private Drawer drawer;
+        private readonly Drawer drawer;
 
         /// <summary>
         /// Creates the ResetPen IVerb
diff --git a/Advanced Software Engineering/Advanced Software Engineering/Verbs/DrawingVerbs/Square.cs b/Advanced Software Engineering/Advanced Software Engineering/Verbs/DrawingVerbs/Square.cs
index 7feeeec..f72c9b4 100644
--- a/Advanced Software Engineering/Advanced Software Engineering/Verbs/DrawingVerbs/Square.cs	
+++ b/Advanced Software Engineering/Advanced Software Engineering/Verbs/DrawingVerbs/Square.cs	
@@ -4,7 +4,7 @@
     /// The Square IVerb class
     /// </summary>
     public class Square : IVerb {
-        private IVerb IVerb;
+        private readonly IVerb IVerb;
 
         /// <summary>
         /// A new Squre instance. Draws squares using <see cref="RegularPolygon"/>
diff --git a/Advanced Software Engineering/Advanced Software Engineering/Verbs/DrawingVerbs/Triangle.cs b/Advanced Software Engineering/Advanced Software Engineering/Verbs/DrawingVerbs/Triangle.cs
index 7fcc29d..31cdb18 100644
--- a/Advanced Software Engineering/Advanced Software Engineering/Verbs/DrawingVerbs/Triangle.cs	
+++ b/Advanced Software Engineering/Advanced Software Engineering/Verbs/DrawingVerbs/Triangle.cs	
@@ -6,7 +6,7 @@ namespace Advanced_Software_Engineering.Verbs.DrawingVerbs {
     /// The Triangle IVerb class
     /// </summary>
     public class Triangle : IVerb {
-        private IVerb IVerb;
+        private readonly IVerb IVerb;
 
         /// <summary>
         /// Creates a new Triangle instance using <see cref="RegularPolygon"/>.