diff --git a/python/gilded_rose.py b/python/gilded_rose.py
index bc5f99ae..db9e414e 100755
--- a/python/gilded_rose.py
+++ b/python/gilded_rose.py
@@ -1,9 +1,23 @@
 # -*- coding: utf-8 -*-
 
+class ITEM_NAME:
+    AGED_BRIE = "Aged Brie"
+    BACKSTAGE_PASS = "Backstage passes to a TAFKAL80ETC concert"
+    SULFURAS = "Sulfuras, Hand of Ragnaros"
+    CONJURED = "Conjured"
+
+
 class GildedRose(object):
+    MAX_QUALITY = 50
+    LEGENDARY_QUALITY = 80
+    LEGENDARY_ITEM = ITEM_NAME.SULFURAS
+    BACKSTAGE_PASS_DOUBLE_THRESHOLD = 10  # Quality increases by 2 when ≤ this
+    BACKSTAGE_PASS_TRIPLE_THRESHOLD = 5  # Quality increases by 3 when ≤ this
+
     def __init__(self, items):
         self.items = items
 
+
     def update_quality(self):
         for item in self.items:
             self.update_item_quality(item)
@@ -12,13 +26,13 @@ class GildedRose(object):
                 self.handle_expired_item(item)
 
     def update_item_quality(self, item):
-        if item.name == "Aged Brie":
+        if item.name == ITEM_NAME.AGED_BRIE:
             self.update_aged_brie(item)
-        elif item.name == "Backstage passes to a TAFKAL80ETC concert":
+        elif item.name == ITEM_NAME.BACKSTAGE_PASS:
             self.update_backstage_pass(item)
-        elif "Conjured" in item.name:
+        elif ITEM_NAME.CONJURED in item.name:
             self.update_conjured_item(item)
-        elif item.name != "Sulfuras, Hand of Ragnaros":
+        elif item.name != ITEM_NAME.SULFURAS:
             self.update_normal_item(item)
 
     def update_conjured_item(self, item):
@@ -26,18 +40,18 @@ class GildedRose(object):
         self.decrease_quality(item)
 
     def update_sell_in(self, item):
-        if item.name != "Sulfuras, Hand of Ragnaros":
+        if item.name != ITEM_NAME.SULFURAS:
             item.sell_in -= 1
 
     def handle_expired_item(self, item):
-        if item.name == "Aged Brie":
+        if item.name == ITEM_NAME.AGED_BRIE:
             self.increase_quality(item)
-        elif item.name == "Backstage passes to a TAFKAL80ETC concert":
+        elif item.name == ITEM_NAME.BACKSTAGE_PASS:
             item.quality = 0
-        elif "Conjured" in item.name:
+        elif ITEM_NAME.CONJURED in item.name:
             self.decrease_quality(item)
             self.decrease_quality(item)
-        elif item.name != "Sulfuras, Hand of Ragnaros":
+        elif item.name != ITEM_NAME.SULFURAS:
             self.decrease_quality(item)
 
     def update_aged_brie(self, item):
@@ -45,22 +59,23 @@ class GildedRose(object):
 
     def update_backstage_pass(self, item):
         self.increase_quality(item)
-        if item.sell_in < 11:
+        if item.sell_in <= self.BACKSTAGE_PASS_DOUBLE_THRESHOLD:
             self.increase_quality(item)
-        if item.sell_in < 6:
+        if item.sell_in <= self.BACKSTAGE_PASS_TRIPLE_THRESHOLD:
             self.increase_quality(item)
 
     def update_normal_item(self, item):
         self.decrease_quality(item)
 
     def increase_quality(self, item):
-        if item.quality < 50:
+        if item.quality < self.MAX_QUALITY:
             item.quality += 1
 
     def decrease_quality(self, item):
         if item.quality > 0:
             item.quality -= 1
 
+
 class Item:
     def __init__(self, name, sell_in, quality):
         self.name = name