diff --git a/game/functions.ink b/game/functions.ink
index d46546a..732e263 100644
--- a/game/functions.ink
+++ b/game/functions.ink
@@ -13,7 +13,9 @@
  ~ return x
 
 === function lastcard(ref list)
-  ~ return LIST_MIN(list)
+  { !x: ~ return "" }
+  ~ temp x = LIST_MIN(list)
+  ~ return x
 
 === function is_clubs(x)
   ~ return (x == two_of_clubs || x == three_of_clubs || x == four_of_clubs || x == five_of_clubs || x == six_of_clubs || x == seven_of_clubs || x == eight_of_clubs || x == nine_of_clubs || x == ten_of_clubs || x == jack_of_clubs || x == queen_of_clubs || x == king_of_clubs || x == ace_of_clubs)
@@ -60,6 +62,8 @@
 
 === function tonumber(x)
   {
+    - x == ():
+      ~ return 0
     - is_two(x):
       ~ return 2
     - is_three(x):
@@ -103,17 +107,30 @@
     ~ return follows(x,y)
   }
 
-=== function can_move_to_full(ref col)
+=== function can_move_to_foundation(ref col)
   ~ temp x = lastcard(col)
   ~ temp y = ""
   {
     - is_spades(x):
-      ~ y = lastcard(full1)
+      ~ y = lastcard(foundation1)
     - is_diamonds(x):
-      ~ y = lastcard(full2)
+      ~ y = lastcard(foundation2)
     - is_clubs(x):
-      ~ y = lastcard(full3)
+      ~ y = lastcard(foundation3)
     - is_hearts(x):
-      ~ y = lastcard(full4)
+      ~ y = lastcard(foundation4)
   }
   ~ return follows(x,y)
+
+=== function can_move_to_empty(ref col, ref empty)
+  {col == () || empty != ():
+    ~ return false
+  }
+  ~ return true
+
+=== function can_move_to_col(ref column_one, ref column_two)
+  ~ temp x = lastcard(column_one)
+  ~ temp y = lastcard(column_two)
+  {!x: ~ return false}
+  {!y:~ return true}
+  ~ return (( (!is_black(x) && is_black(y)) || (is_black(x) && !is_black(y)) ) && follows(y,x) )
diff --git a/game/game.ink b/game/game.ink
index 1e5c9b1..e52ffd4 100644
--- a/game/game.ink
+++ b/game/game.ink
@@ -14,10 +14,10 @@ VAR col8 = ()
 VAR empty1 = ()
 VAR empty2 = ()
 
-VAR full1 = ()
-VAR full2 = ()
-VAR full3 = ()
-VAR full4 = ()
+VAR foundation1 = ()
+VAR foundation2 = ()
+VAR foundation3 = ()
+VAR foundation4 = ()
 
 // Put 7 random cards to slot 1
 ~ col1 += randomcard(cards)
@@ -87,10 +87,10 @@ VAR full4 = ()
 <div id="playing_field"> <>
 <div id="empty1" class="cardempty">{empty1}</div> <>
 <div id="empty2" class="cardempty">{empty2}</div> <>
-<div id="full1" class="cardstack">{full1}</div> <>
-<div id="full2" class="cardstack">{full2}</div> <>
-<div id="full3" class="cardstack">{full3}</div> <>
-<div id="full4" class="cardstack">{full4}</div> <>
+<div id="foundation1" class="cardstack">{foundation1}</div> <>
+<div id="foundation2" class="cardstack">{foundation2}</div> <>
+<div id="foundation3" class="cardstack">{foundation3}</div> <>
+<div id="foundation4" class="cardstack">{foundation4}</div> <>
 <div id="col1" class="cardcolumn">{col1}</div> <>
 <div id="col2" class="cardcolumn">{col2}</div> <>
 <div id="col3" class="cardcolumn">{col3}</div> <>
@@ -101,12 +101,11 @@ VAR full4 = ()
 <div id="col8" class="cardcolumn">{col8}</div> <>
 </div>
 
-+ {empty1 == () && col1 != ()} Move {lastcard(col1)} from col1 to empty1
-  -> move_from_col1_to_empty1
-+ {empty2 == () && col1 != ()} Move {lastcard(col1)} from col1 to empty2
-  -> move_from_col1_to_empty2
-
--> END
++ {can_move_to_empty(col1, empty1)} [Move {lastcard(col1)} to empty space] -> move_from_col1_to_empty1
++ {empty1 != () && can_move_to_empty(col1, empty2)} [Move {lastcard(col1)} to empty space] -> move_from_col1_to_empty2
++ {can_move_to_col(empty1, col1)} [Move {lastcard(empty1)} to col1] -> move_from_empty1_to_col1
++ {can_move_to_col(empty2, col1)} [Move {lastcard(empty2)} to col1] -> move_from_empty2_to_col1
++ -> END
 
 === move_from_col1_to_empty1
 
@@ -119,3 +118,15 @@ VAR full4 = ()
 ~ empty2 += pop(col1)
 
 -> main
+
+=== move_from_empty1_to_col1
+
+~ col1 += pop(empty1)
+
+-> main
+
+=== move_from_empty2_to_col1
+
+~ col1 += pop(empty2)
+
+-> main
diff --git a/scss/style.scss b/scss/style.scss
index 02a15ad..55e07bd 100644
--- a/scss/style.scss
+++ b/scss/style.scss
@@ -270,7 +270,7 @@ body {
   }
 }
 @for $i from 1 through 4 {
-  #full#{$i} {
+  #foundation#{$i} {
     right: ($card_width * ($i - 1) + ($gutter / 2));
   }
 }