diff --git a/views/application.coffee b/views/application.coffee
index 0f683ad..6c85497 100644
--- a/views/application.coffee
+++ b/views/application.coffee
@@ -1,5 +1,40 @@
 window.Nikoli = Nikoli = {}
 
+class Nikoli.Game
+  constructor: (@board, @name) ->
+    @name = 'nikoli' unless @name?
+    @board.classList.add @name
+
+    @grid = document.createElement 'div'
+    @grid.classList.add 'game-container'
+    @board.appendChild @grid
+
+    buttons_div = document.createElement 'div'
+    buttons = {check: 'Check', reset: 'Reset', newgame: 'New game', help: '?'}
+
+    for k,v of buttons
+      button = document.createElement 'button'
+      button.innerHTML = v
+      button.classList.add k
+
+      buttons_div.appendChild button
+
+    @board.appendChild buttons_div
+
+    @board.querySelector('.check').addEventListener('click', @check.bind(this))
+    @board.querySelector('.reset').addEventListener('click', @reset.bind(this))
+
+  check: ->
+    errors = @errors()
+
+    if errors.length == 0
+      alert 'Congratulations!'
+    else
+      alert errors.map((el) -> el.message).join()
+
+  reset: ->
+    @generate()
+
 class Nikoli.Stream
   constructor: (@game) ->
     @cells = []
diff --git a/views/hitori.coffee b/views/hitori.coffee
index 645b099..b475c07 100644
--- a/views/hitori.coffee
+++ b/views/hitori.coffee
@@ -1,33 +1,6 @@
-window.Hitori = class Nurikabe
-  constructor: (@board) ->
-    @board.classList.add 'hitori'
-
-    @grid = document.createElement 'div'
-    @grid.classList.add 'game-container'
-    @board.appendChild @grid
-
-    buttons_div = document.createElement 'div'
-    buttons = {check: 'Check', reset: 'Reset', newgame: 'New game', help: '?'}
-
-    for k,v of buttons
-      button = document.createElement 'button'
-      button.innerHTML = v
-      button.classList.add k
-
-      buttons_div.appendChild button
-
-    @board.appendChild buttons_div
-
-    @board.querySelector('.check').addEventListener('click', @check.bind(this))
-    @board.querySelector('.reset').addEventListener('click', @reset.bind(this))
-
-  check: ->
-    errors = @errors()
-
-    if errors.length == 0
-      alert 'Congratulations!'
-    else
-      alert errors.map((el) -> el.message).join()
+class Nikoli.Hitori extends Nikoli.Game
+  constructor: (@board, @name = 'hitori') ->
+    super @board, @name
 
   errors: ->
     solution = @toArray()
@@ -72,9 +45,6 @@ window.Hitori = class Nurikabe
 
     return
 
-  reset: ->
-    @generate()
-
   toggle: (cell) ->
     if cell.classList.contains 'black'
       cell.classList.remove 'black'
diff --git a/views/hitori.slim b/views/hitori.slim
index 0c4f3af..784949a 100644
--- a/views/hitori.slim
+++ b/views/hitori.slim
@@ -17,6 +17,6 @@ javascript:
       [3,3,3,2,4,6,1,7]
     ];
 
-    hitori = new Hitori(document.getElementById('board'));
+    hitori = new Nikoli.Hitori(document.getElementById('board'));
     hitori.generate(game);
   });
diff --git a/views/nurikabe.coffee b/views/nurikabe.coffee
index 6800ea9..999ce27 100644
--- a/views/nurikabe.coffee
+++ b/views/nurikabe.coffee
@@ -1,31 +1,6 @@
-window.Nurikabe = class Nurikabe
-  constructor: (@board) ->
-    @grid = document.createElement 'div'
-    @grid.classList.add 'game-container'
-    @board.appendChild @grid
-
-    buttons_div = document.createElement 'div'
-    buttons = {check: 'Check', reset: 'Reset', newgame: 'New game', help: '?'}
-
-    for k,v of buttons
-      button = document.createElement 'button'
-      button.innerHTML = v
-      button.classList.add k
-
-      buttons_div.appendChild button
-
-    @board.appendChild buttons_div
-
-    @board.querySelector('.check').addEventListener('click', @check.bind(this))
-    @board.querySelector('.reset').addEventListener('click', @reset.bind(this))
-
-  check: ->
-    errors = @errors()
-
-    if errors.length == 0
-      alert 'Congratulations!'
-    else
-      alert errors.map((el) -> el.message).join()
+class Nikoli.Nurikabe extends Nikoli.Game
+  constructor: (@board, @name = 'nurikabe') ->
+    super @board, @name
 
   errors: ->
     solution = @toArray()
@@ -75,9 +50,6 @@ window.Nurikabe = class Nurikabe
 
     return
 
-  reset: ->
-    @generate()
-
   toggle: (cell) ->
     if cell.classList.contains 'black'
       cell.classList.remove 'black'
diff --git a/views/nurikabe.slim b/views/nurikabe.slim
index 24e709f..86ba49e 100644
--- a/views/nurikabe.slim
+++ b/views/nurikabe.slim
@@ -6,7 +6,7 @@ h1 Nurikabe
 script type="text/javascript" src="/nurikabe.js"
 javascript:
   document.addEventListener("DOMContentLoaded", function() {
-    nurikabe = new Nurikabe(document.getElementById('board'));
+    nurikabe = new Nikoli.Nurikabe(document.getElementById('board'));
 
     xmlhttp = new XMLHttpRequest();
     xmlhttp.open("GET", "#{url('/data/nurikabe/5x5.json')}");
diff --git a/views/sudoku.coffee b/views/sudoku.coffee
index b82f26c..36a26be 100644
--- a/views/sudoku.coffee
+++ b/views/sudoku.coffee
@@ -1,33 +1,6 @@
-window.Sudoku = class Sudoku
-  constructor: (@board) ->
-    @board.classList.add 'sudoku'
-
-    @grid = document.createElement 'div'
-    @grid.classList.add 'game-container'
-    @board.appendChild @grid
-
-    buttons_div = document.createElement 'div'
-    buttons = {check: 'Check', reset: 'Reset', newgame: 'New game', help: '?'}
-
-    for k,v of buttons
-      button = document.createElement 'button'
-      button.innerHTML = v
-      button.classList.add k
-
-      buttons_div.appendChild button
-
-    @board.appendChild buttons_div
-
-    @board.querySelector('.check').addEventListener('click', @check.bind(this))
-    @board.querySelector('.reset').addEventListener('click', @reset.bind(this))
-
-  check: ->
-    errors = @errors()
-
-    if errors.length == 0
-      alert 'Congratulations!'
-    else
-      alert errors.map((el) -> el.message).join()
+class Nikoli.Sudoku extends Nikoli.Game
+  constructor: (@board, @name = 'sudoku') ->
+    super @board, @name
 
   errors: ->
     solution = @toArray()
@@ -65,9 +38,6 @@ window.Sudoku = class Sudoku
 
     return
 
-  reset: ->
-    @generate()
-
   toggle: (cell) ->
     if cell.classList.contains 'black'
       cell.classList.remove 'black'
diff --git a/views/sudoku.slim b/views/sudoku.slim
index 3448bb4..fc9b5e7 100644
--- a/views/sudoku.slim
+++ b/views/sudoku.slim
@@ -6,7 +6,7 @@ h1 Sudoku
 script type="text/javascript" src="/sudoku.js"
 javascript:
   document.addEventListener("DOMContentLoaded", function() {
-    sudoku = new Sudoku(document.getElementById('board'));
+    sudoku = new Nikoli.Sudoku(document.getElementById('board'));
 
     xmlhttp = new XMLHttpRequest();
     xmlhttp.open("GET", "#{url('/data/sudoku/gnome-sudoku_easy.json')}");