diff --git a/src/Types/GameBoard.hs b/src/Types/GameBoard.hs
index f6516bf..1b81e3f 100644
--- a/src/Types/GameBoard.hs
+++ b/src/Types/GameBoard.hs
@@ -1,6 +1,7 @@
 {-# LANGUAGE FlexibleContexts #-}
 {-# LANGUAGE NamedFieldPuns #-}
 {-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE TupleSections #-}
 {-# LANGUAGE UndecidableInstances #-}
 
 module Types.GameBoard where
@@ -20,8 +21,10 @@ data GameBoard mode = MkGameBoard
     , gameMode :: mode
     }
 
-clear = undefined
 clear :: (GameMode mode) => BoardPosition -> BoardPosition -> GameBoard mode -> GameBoard mode
+clear topLeft bottomRight gBoard@MkGameBoard{board} = gBoard{board = newCells}
+  where
+    newCells = board // map (,Nothing) (range (topLeft, bottomRight))
 
 selectCheck :: (GameMode mode) => BoardPosition -> BoardPosition -> GameBoard mode -> Bool
 selectCheck topLeft bottomRight board@MkGameBoard{gameMode} =
diff --git a/test/Spec.hs b/test/Spec.hs
index 2cbed54..803b34e 100644
--- a/test/Spec.hs
+++ b/test/Spec.hs
@@ -3,7 +3,7 @@
 
 module Spec where
 
-import Data.Array (array)
+import Data.Array (array, elems)
 import Display (displayText)
 import Test.Hspec
 import Types.GameBoard
@@ -27,3 +27,7 @@ spec = describe "gameboard" do
     it "validates a move" do
         selectCheck (0, 0) (1, 1) gameBoard `shouldBe` True
         selectCheck (0, 0) (0, 1) gameBoard `shouldBe` False
+
+    it "clears properly" do
+        let cleared = clear (0, 0) (0, 1) gameBoard
+        elems (board cleared) `shouldBe` [Nothing, Nothing, Just $ IntTile 3, Just $ IntTile 4]