diff --git a/board2.py b/board2.py
index f263e12..28581f4 100644
--- a/board2.py
+++ b/board2.py
@@ -1,4 +1,5 @@
 #!/usr/bin/env python
+import copy
 from pos import TwoDPos
 
 class BoardTools:
@@ -19,12 +20,20 @@ class BoardTools:
         if b[2][0] == b[1][1] == b[0][2]:
             if b[2][0] != Board.unplayed:
                 return b[2][0]
+        spaces = 0
+        for i in range(3):
+            for j in range(3):
+                if b[i][j] != Board.unplayed:
+                    spaces += 1
+        if spaces == 9:
+            return Board.tie
         return Board.unplayed
 
 class Board:
     unplayed = 0
     cross = 1
     nought = 2
+    tie = 3
 
     def __init__(self):
         self.board = [
@@ -40,6 +49,14 @@ class Board:
         self.moves = []
         self.turn = Board.cross
 
+    def copy(self):
+        new = Board()
+        new.board = copy.deepcopy(self.board)
+        new.moves = copy.deepcopy(self.moves)
+        new.turn = copy.deepcopy(self.turn)
+
+        return new
+
     def set(self, a, b, c, d, val):
         self.board[a][b][c][d] = val
 
@@ -79,6 +96,10 @@ class Board:
         return buf
 
     def possible(self):
+        # check if board is in final state
+        isFinal = BoardTools.winning(self, self.metaboard())
+        if isFinal in [Board.tie, Board.cross, Board.nought]:
+            return []
         try:
             move = self.moves[-1]
         except IndexError:
@@ -92,7 +113,7 @@ class Board:
             return buf
 
         local = move.local()
-        if self.subWin(local[2], local[3]):
+        if self.subWin(local[2], local[3]) in [Board.tie, Board.nought, Board.cross]:
             return self.reachableEmpty()
 
         buf = []