diff --git a/csharp/ApprovalTest.ThirtyDays.received.txt b/csharp/ApprovalTest.ThirtyDays.received.txt
index cd66984f..4b5ab41f 100644
--- a/csharp/ApprovalTest.ThirtyDays.received.txt
+++ b/csharp/ApprovalTest.ThirtyDays.received.txt
@@ -21,7 +21,7 @@ Sulfuras, Hand of Ragnaros, -1, 80
 Backstage passes to a TAFKAL80ETC concert, 14, 21
 Backstage passes to a TAFKAL80ETC concert, 9, 50
 Backstage passes to a TAFKAL80ETC concert, 4, 50
-Conjured Mana Cake, 2, 5
+Conjured Mana Cake, 2, 4
 
 -------- day 2 --------
 name, sellIn, quality
@@ -33,7 +33,7 @@ Sulfuras, Hand of Ragnaros, -1, 80
 Backstage passes to a TAFKAL80ETC concert, 13, 22
 Backstage passes to a TAFKAL80ETC concert, 8, 50
 Backstage passes to a TAFKAL80ETC concert, 3, 50
-Conjured Mana Cake, 1, 4
+Conjured Mana Cake, 1, 2
 
 -------- day 3 --------
 name, sellIn, quality
@@ -45,7 +45,7 @@ Sulfuras, Hand of Ragnaros, -1, 80
 Backstage passes to a TAFKAL80ETC concert, 12, 23
 Backstage passes to a TAFKAL80ETC concert, 7, 50
 Backstage passes to a TAFKAL80ETC concert, 2, 50
-Conjured Mana Cake, 0, 3
+Conjured Mana Cake, 0, 0
 
 -------- day 4 --------
 name, sellIn, quality
@@ -57,7 +57,7 @@ Sulfuras, Hand of Ragnaros, -1, 80
 Backstage passes to a TAFKAL80ETC concert, 11, 24
 Backstage passes to a TAFKAL80ETC concert, 6, 50
 Backstage passes to a TAFKAL80ETC concert, 1, 50
-Conjured Mana Cake, -1, 1
+Conjured Mana Cake, -1, 0
 
 -------- day 5 --------
 name, sellIn, quality
@@ -66,7 +66,7 @@ Aged Brie, -3, 8
 Elixir of the Mongoose, 0, 2
 Sulfuras, Hand of Ragnaros, 0, 80
 Sulfuras, Hand of Ragnaros, -1, 80
-Backstage passes to a TAFKAL80ETC concert, 10, 25
+Backstage passes to a TAFKAL80ETC concert, 10, 26
 Backstage passes to a TAFKAL80ETC concert, 5, 50
 Backstage passes to a TAFKAL80ETC concert, 0, 50
 Conjured Mana Cake, -2, 0
@@ -78,7 +78,7 @@ Aged Brie, -4, 10
 Elixir of the Mongoose, -1, 0
 Sulfuras, Hand of Ragnaros, 0, 80
 Sulfuras, Hand of Ragnaros, -1, 80
-Backstage passes to a TAFKAL80ETC concert, 9, 27
+Backstage passes to a TAFKAL80ETC concert, 9, 28
 Backstage passes to a TAFKAL80ETC concert, 4, 50
 Backstage passes to a TAFKAL80ETC concert, -1, 0
 Conjured Mana Cake, -3, 0
@@ -90,7 +90,7 @@ Aged Brie, -5, 12
 Elixir of the Mongoose, -2, 0
 Sulfuras, Hand of Ragnaros, 0, 80
 Sulfuras, Hand of Ragnaros, -1, 80
-Backstage passes to a TAFKAL80ETC concert, 8, 29
+Backstage passes to a TAFKAL80ETC concert, 8, 30
 Backstage passes to a TAFKAL80ETC concert, 3, 50
 Backstage passes to a TAFKAL80ETC concert, -2, 0
 Conjured Mana Cake, -4, 0
@@ -102,7 +102,7 @@ Aged Brie, -6, 14
 Elixir of the Mongoose, -3, 0
 Sulfuras, Hand of Ragnaros, 0, 80
 Sulfuras, Hand of Ragnaros, -1, 80
-Backstage passes to a TAFKAL80ETC concert, 7, 31
+Backstage passes to a TAFKAL80ETC concert, 7, 32
 Backstage passes to a TAFKAL80ETC concert, 2, 50
 Backstage passes to a TAFKAL80ETC concert, -3, 0
 Conjured Mana Cake, -5, 0
@@ -114,7 +114,7 @@ Aged Brie, -7, 16
 Elixir of the Mongoose, -4, 0
 Sulfuras, Hand of Ragnaros, 0, 80
 Sulfuras, Hand of Ragnaros, -1, 80
-Backstage passes to a TAFKAL80ETC concert, 6, 33
+Backstage passes to a TAFKAL80ETC concert, 6, 34
 Backstage passes to a TAFKAL80ETC concert, 1, 50
 Backstage passes to a TAFKAL80ETC concert, -4, 0
 Conjured Mana Cake, -6, 0
@@ -126,7 +126,7 @@ Aged Brie, -8, 18
 Elixir of the Mongoose, -5, 0
 Sulfuras, Hand of Ragnaros, 0, 80
 Sulfuras, Hand of Ragnaros, -1, 80
-Backstage passes to a TAFKAL80ETC concert, 5, 35
+Backstage passes to a TAFKAL80ETC concert, 5, 37
 Backstage passes to a TAFKAL80ETC concert, 0, 50
 Backstage passes to a TAFKAL80ETC concert, -5, 0
 Conjured Mana Cake, -7, 0
@@ -138,7 +138,7 @@ Aged Brie, -9, 20
 Elixir of the Mongoose, -6, 0
 Sulfuras, Hand of Ragnaros, 0, 80
 Sulfuras, Hand of Ragnaros, -1, 80
-Backstage passes to a TAFKAL80ETC concert, 4, 38
+Backstage passes to a TAFKAL80ETC concert, 4, 40
 Backstage passes to a TAFKAL80ETC concert, -1, 0
 Backstage passes to a TAFKAL80ETC concert, -6, 0
 Conjured Mana Cake, -8, 0
@@ -150,7 +150,7 @@ Aged Brie, -10, 22
 Elixir of the Mongoose, -7, 0
 Sulfuras, Hand of Ragnaros, 0, 80
 Sulfuras, Hand of Ragnaros, -1, 80
-Backstage passes to a TAFKAL80ETC concert, 3, 41
+Backstage passes to a TAFKAL80ETC concert, 3, 43
 Backstage passes to a TAFKAL80ETC concert, -2, 0
 Backstage passes to a TAFKAL80ETC concert, -7, 0
 Conjured Mana Cake, -9, 0
@@ -162,7 +162,7 @@ Aged Brie, -11, 24
 Elixir of the Mongoose, -8, 0
 Sulfuras, Hand of Ragnaros, 0, 80
 Sulfuras, Hand of Ragnaros, -1, 80
-Backstage passes to a TAFKAL80ETC concert, 2, 44
+Backstage passes to a TAFKAL80ETC concert, 2, 46
 Backstage passes to a TAFKAL80ETC concert, -3, 0
 Backstage passes to a TAFKAL80ETC concert, -8, 0
 Conjured Mana Cake, -10, 0
@@ -174,7 +174,7 @@ Aged Brie, -12, 26
 Elixir of the Mongoose, -9, 0
 Sulfuras, Hand of Ragnaros, 0, 80
 Sulfuras, Hand of Ragnaros, -1, 80
-Backstage passes to a TAFKAL80ETC concert, 1, 47
+Backstage passes to a TAFKAL80ETC concert, 1, 49
 Backstage passes to a TAFKAL80ETC concert, -4, 0
 Backstage passes to a TAFKAL80ETC concert, -9, 0
 Conjured Mana Cake, -11, 0
diff --git a/csharp/GildedRose.cs b/csharp/GildedRose.cs
index c5336e08..46ee0006 100644
--- a/csharp/GildedRose.cs
+++ b/csharp/GildedRose.cs
@@ -1,94 +1,71 @@
-using System.Collections.Generic;
+using System;
+using System.Collections.Generic;
+using System.Runtime.Remoting.Messaging;
 
 namespace csharp
 {
     public class GildedRose
     {
+
         private readonly IList<Item> _items;
 
         public GildedRose(IList<Item> items)
             => _items = items;
 
+        private static int GetQualityChange(Item item)
+        {
+            var sellIn = item.SellIn;
+
+            switch (item.Name)
+            {
+                case "Sulfuras, Hand of Ragnaros":
+                    return 0;
+                case "Backstage passes to a TAFKAL80ETC concert":
+                    if (sellIn > 9)
+                    {
+                        return 1;
+                    }
+                    else if (sellIn > 4)
+                    {
+                        return 2;
+                    }
+                    else if (sellIn >= 0)
+                    {
+                        return 3;
+                    }
+                    else
+                    {
+                        return -item.Quality;
+                    }
+                case "Aged Brie":
+                    return sellIn < 0 ? 2 : 1;
+                case "Conjured Mana Cake":
+                    return sellIn < 0 ? -4 : -2;
+                default:
+                    return sellIn < 0 ? -2 : -1;
+            }
+        }
+
         public void UpdateQuality()
         {
             foreach (var item in _items)
             {
-                var qualityDegradationMultiplier = item.Name == "Conjured Mana Cake" ? 2 : 1;
+                item.SellIn--;
 
-                if (item.Name != "Aged Brie"
-                    && item.Name != "Backstage passes to a TAFKAL80ETC concert")
-                {
-                    if (item.Quality > 0)
-                    {
-                        if (item.Name != "Sulfuras, Hand of Ragnaros")
-                        {
-                            item.Quality -= qualityDegradationMultiplier;
-                        }
-                    }
-                }
-                else
-                {
-                    if (item.Quality < 50)
-                    {
-                        item.Quality++;
+                var qualityChange = GetQualityChange(item);
 
-                        if (item.Name == "Backstage passes to a TAFKAL80ETC concert")
-                        {
-                            if (item.SellIn < 11)
-                            {
-                                if (item.Quality < 50)
-                                {
-                                    item.Quality++;
-                                }
-                            }
-
-                            if (item.SellIn < 6)
-                            {
-                                if (item.Quality < 50)
-                                {
-                                    item.Quality++;
-                                }
-                            }
-                        }
-                    }
-                }
+                item.Quality += qualityChange;
 
                 if (item.Name != "Sulfuras, Hand of Ragnaros")
                 {
-                    item.SellIn--;
-                }
-
-                if (item.SellIn >= 0)
-                {
-                    continue;
-                }
-
-                if (item.Name != "Aged Brie")
-                {
-                    if (item.Name != "Backstage passes to a TAFKAL80ETC concert")
-                    {
-                        if (item.Quality <= 0)
-                        {
-                            continue;
-                        }
-
-                        if (item.Name != "Sulfuras, Hand of Ragnaros")
-                        {
-                            item.Quality -= qualityDegradationMultiplier;
-                        }
-                    }
-                    else
-                    {
-                        item.Quality = 0;
-                    }
+                    item.Quality = Math.Min(50, item.Quality);
                 }
                 else
                 {
-                    if (item.Quality < 50)
-                    {
-                        item.Quality++;
-                    }
+                    item.SellIn++;
                 }
+
+                item.Quality = Math.Max(0, item.Quality);
             }
         }
     }