diff --git a/views/application.scss b/views/application.scss
index 6fdac91..d16f334 100644
--- a/views/application.scss
+++ b/views/application.scss
@@ -68,3 +68,24 @@ ul {
 .black {
   background-color: #aaa;
 }
+
+.sudoku {
+  $sudoku-separation: 5px;
+
+  .grid-row:nth-child(3n) {
+    margin-bottom: $sudoku-separation;
+  }
+  .grid-cell:nth-child(3n) {
+    margin-right: $sudoku-separation;
+  }
+
+  input {
+    text-align: center;
+    width: 80%;
+    height: 80%;
+    border: none;
+    background: transparent;
+    font-family: Verdana,Arial,sans-serif;
+    font-size: 1.2em;
+  }
+}
diff --git a/views/sudoku.coffee b/views/sudoku.coffee
new file mode 100644
index 0000000..b82f26c
--- /dev/null
+++ b/views/sudoku.coffee
@@ -0,0 +1,86 @@
+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()
+
+  errors: ->
+    solution = @toArray()
+    errors = []
+
+    for i in [0..8]
+      square = []
+      column = []
+      row = solution[i]
+
+      for j in [0..8]
+        column.push(solution[j][i])
+        square.push(solution[(Math.floor(i/3)*3) + Math.floor(j/3)][(i%3*3) + (j%3)])
+
+      console.log square
+      console.log column
+      ###
+      # check square [i%3*3][j/3*3]
+      # check row [i][.]
+      # check column [.][i]
+      ###
+
+    errors
+
+  generate: (game, solution = false) ->
+    @game = game if game?
+    @grid.innerHTML = @game.map((row) ->
+      '<div class="grid-row">' + row.map((cell) ->
+        if cell <= 0
+          "<div class=\"grid-cell empty\"><input type=\"text\" #{if cell < 0 then "value=\"#{Math.abs(cell)}\""} /></div>"
+        else
+          "<div class=\"grid-cell white\">#{cell}</div>"
+      ).join('') + '</div>'
+    ).join('')
+
+    return
+
+  reset: ->
+    @generate()
+
+  toggle: (cell) ->
+    if cell.classList.contains 'black'
+      cell.classList.remove 'black'
+      cell.classList.add 'white'
+    else if cell.classList.contains 'white'
+      cell.classList.remove 'white'
+    else
+      cell.classList.add 'black'
+
+  toArray: ->
+    [].map.call @grid.querySelectorAll('.grid-row'), (row) ->
+      [].map.call row.querySelectorAll('.grid-cell'), (cell) ->
+        if cell.classList.contains('empty')
+          -parseInt(cell.querySelector('input').value)
+        else
+          parseInt(cell.innerHTML)
diff --git a/views/sudoku.slim b/views/sudoku.slim
new file mode 100644
index 0000000..1e79c26
--- /dev/null
+++ b/views/sudoku.slim
@@ -0,0 +1,23 @@
+- content_for(:title) { 'Sudoku' }
+
+h1 Sudoku
+#board
+
+script type="text/javascript" src="/sudoku.js"
+javascript:
+  document.addEventListener("DOMContentLoaded", function() {
+    var game = [
+      [3,7,9,-5,-2,-6,-8,1,4],
+      [-5,6,-4,-3,1,-8,-9,7,-2],
+      [-2,8,-1,-4,-7,9,-3,-6,5],
+      [4,3,5,-2,-6,7,-1,-9,-8],
+      [-6,9,-8,-1,4,-3,-5,2,-7],
+      [-7,-1,-2,8,-9,-5,4,3,6],
+      [9,-2,-3,7,-5,-4,-6,8,-1],
+      [-1,4,-6,-9,8,-2,-7,5,-3],
+      [8,5,-7,-6,-3,-1,2,4,9]
+    ];
+
+    sudoku = new Sudoku(document.getElementById('board'));
+    sudoku.generate(game);
+  });