diff --git a/drawutils.cpp b/drawutils.cpp
index f0c7701..c9418f9 100644
--- a/drawutils.cpp
+++ b/drawutils.cpp
@@ -52,7 +52,7 @@ bool DrawUtils::draw(SDL_Surface* dest, SDL_Surface* drawable, int x, int y,
     return true;
 }
 
-#include "debug.h"
+
 void DrawUtils::draw_line(SDL_Surface* dest, Sint16 x1, Sint16 y1, Sint16 x2, Sint16 y2, Uint16 width, Uint32 colour)
 {
     float dx, dy, len;
@@ -60,7 +60,7 @@ void DrawUtils::draw_line(SDL_Surface* dest, Sint16 x1, Sint16 y1, Sint16 x2, Si
 
     SDL_Rect pen;
 
-    len = MathUtils::distance(x1,y1,x2,y2);
+    len = MathUtils::distance(x1, y1, 0, x2, y2, 0);
 
     // dx and dy represent the amount we move
     // each step in our drawing loop
diff --git a/gamedata.cpp b/gamedata.cpp
index 485fa62..7d5d36f 100644
--- a/gamedata.cpp
+++ b/gamedata.cpp
@@ -38,7 +38,7 @@ void GameData::toggle_turn()
 void GameData::do_vertex(int x, int y, int r)
 {
     if (current != NULL &&
-	(MathUtils::distance(current->x, current->y, x, y)
+	(MathUtils::distance(current->x, current->y, current->z, x, y, 0)
 	 > get_range()))
     {
 	select_vertex(x, y);
@@ -51,12 +51,12 @@ void GameData::do_vertex(int x, int y, int r)
 
     if (mode == MODE_MOVE)
     {
-	if (point_in_vertex(x, y)) select_vertex(x, y);
-	else add_vertex(x, y, r, colour);
+	if (point_in_vertex(x, y, 0)) select_vertex(x, y);
+	else add_vertex(x, y, 0, r, colour);
     }
     if (mode == MODE_ATTACK)
     {
-	Vertex* v = vertex_at(x, y);
+	Vertex* v = vertex_at(x, y, 0);
 	if (v == NULL) return;
 
 	if (v->colour == colour) select_vertex(x, y);
@@ -72,7 +72,7 @@ void GameData::select_vertex(int x, int y)
 	 cursor != vertices.end(); cursor++)
     {
 	Vertex* v = *cursor;
-	if ((MathUtils::distance(v->x, v->y, x, y) <= v->r) &&
+	if ((MathUtils::distance(v->x, v->y, v->z, x, y, 0) <= v->r) &&
 	    (v->colour == PLAYER1_COLOUR && player == PLAYER1 ||
 	     v->colour == PLAYER2_COLOUR && player == PLAYER2))
 	{
@@ -83,7 +83,7 @@ void GameData::select_vertex(int x, int y)
 }
 
 
-bool GameData::add_vertex(int x, int y, int r, int colour)
+bool GameData::add_vertex(int x, int y, int z, int r, int colour)
 {
     if (mode == MODE_ATTACK) return false;
 
@@ -93,7 +93,7 @@ bool GameData::add_vertex(int x, int y, int r, int colour)
 	if ((player == PLAYER1 && !player1_played) ||
 	    (player == PLAYER2 && !player2_played))
 	{
-	    Graph::add_vertex(x, y, r, colour, 10);
+	    Graph::add_vertex(x, y, z, r, colour, 10);
 #ifdef DEBUG
 	    fprintf(stderr, "debug: GameData::add_vertex(): strength=%2.f\n",
 		    calculate_strength(*(vertices.rbegin())));
@@ -106,7 +106,7 @@ bool GameData::add_vertex(int x, int y, int r, int colour)
 	return false;
     }
 
-    if (Graph::add_vertex(x, y, r, colour, 10, current))
+    if (Graph::add_vertex(x, y, z, r, colour, 10, current))
     {
 #ifdef DEBUG
 	fprintf(stderr, "debug: GameData::add_vertex(): strength=%.2f\n",
@@ -191,7 +191,9 @@ int GameData::get_range(Vertex* node)
 	    cursor != neighbors.end(); cursor++)
 	{
 	    Vertex* v = *cursor;
-	    range -= (100 - MathUtils::distance(v->x, v->y, node->x, node->y)) / 2;
+	    range -= (100 - MathUtils::distance(v->x, v->y, v->z,
+						node->x, node->y, node->z))
+		/ 2;
 	}
 	if (range < 0) range = 0;
 	return range;
diff --git a/gamedata.h b/gamedata.h
index 1b7bb81..77c38e4 100644
--- a/gamedata.h
+++ b/gamedata.h
@@ -27,7 +27,7 @@ class GameData : public Graph
     void select_vertex(int x, int y);
     void attack_vertex(Vertex* target);
 
-    bool add_vertex(int x, int y, int r, int colour);
+    bool add_vertex(int x, int y, int z, int r, int colour);
 
     Mode get_mode() const { return mode; }
     Mode set_mode(Mode m) { mode = m; }
diff --git a/graph.cpp b/graph.cpp
index 8f3d8e3..f26d0e4 100644
--- a/graph.cpp
+++ b/graph.cpp
@@ -22,39 +22,44 @@ Graph::~Graph()
     }
 }
 
-bool Graph::point_in_vertex(int x, int y)
+
+// In 3-space, this will be less useful, because we'll be clicking on the
+// objects themselves... but we'll cross that bridge when we get there
+bool Graph::point_in_vertex(int x, int y, int z)
 {
     for (list<Vertex*>::iterator cursor = vertices.begin();
 	 cursor != vertices.end(); cursor++)
     {
 	Vertex* v = *cursor;
-	if (MathUtils::distance(v->x, v->y, x, y) <= v->r) return true;
+	if (MathUtils::distance(v->x, v->y, v->z, x, y, z) <= v->r)
+	    return true;
     }
 
     return false;
 }
 
 
-Vertex * Graph::vertex_at(int x, int y)
+Vertex * Graph::vertex_at(int x, int y, int z)
 {
     for (list<Vertex*>::iterator cursor = vertices.begin();
 	 cursor != vertices.end(); cursor++)
     {
 	Vertex* v = *cursor;
-	if (MathUtils::distance(v->x, v->y, x, y) <= v->r) return v;
+	if (MathUtils::distance(v->x, v->y, v->z, x, y, z) <= v->r) return v;
     }
 
     return NULL;
 }
 
 
-bool Graph::vertex_would_overlap(int x, int y, int r)
+bool Graph::vertex_would_overlap(int x, int y, int z, int r)
 {
     for (list<Vertex*>::iterator cursor = vertices.begin();
 	 cursor != vertices.end(); cursor++)
     {
 	Vertex* v = *cursor;
-	if (MathUtils::distance(v->x, v->y, x, y) <= v->r + r) return true;
+	if (MathUtils::distance(v->x, v->y, v->z, x, y, z) <= v->r + r)
+	    return true;
     }
 
     return false;
@@ -82,15 +87,15 @@ bool Graph::crosses_edge(Vertex* a, Vertex* b)
 }
 
 
-bool Graph::add_vertex(int x, int y, int r, int colour, int score, Vertex* src)
+bool Graph::add_vertex(int x, int y, int z, int r, int colour, int score, Vertex* src)
 {
-    Vertex* v = new Vertex(x, y, r, colour, score);
+    Vertex* v = new Vertex(x, y, z, r, colour, score);
 
     // Make sure the nodes won't overlap
-    if (vertex_would_overlap(v->x, v->y, v->r))
+    if (vertex_would_overlap(v->x, v->y, v->z, v->r))
     {
 #ifdef DEBUG
-	fprintf(stderr, "debug: Graph::add_vertex(): failed to add due to vertex collision: x=%d, y=%d, r=%d\n", v->x, v->y, v->r);
+	fprintf(stderr, "debug: Graph::add_vertex(): failed to add due to vertex collision: x=%d, y=%d, z=%d, r=%d\n", v->x, v->y, v->z, v->r);
 #endif
 	delete v;
 	return false;
@@ -114,7 +119,7 @@ bool Graph::add_vertex(int x, int y, int r, int colour, int score, Vertex* src)
     vertices.push_back(v);
 
 #ifdef DEBUG
-    fprintf(stderr, "debug: Graph::add_vertex(): added: x=%d, y=%d, r=%d, score=%d, colour=%x\n", v->x, v->y, v->r, v->score, v->colour);
+    fprintf(stderr, "debug: Graph::add_vertex(): added: x=%d, y=%d, z=%d, r=%d, score=%d, colour=%x\n", v->x, v->y, v->z, v->r, v->score, v->colour);
 #endif
 
     return true;
@@ -157,10 +162,11 @@ void Graph::remove_vertex(Vertex* target)
 }
 
 
-Vertex::Vertex(int x, int y, int r, int colour, int score)
+Vertex::Vertex(int x, int y, int z, int r, int colour, int score)
 {
     this->x = x;
     this->y = y;
+    this->z = z;
     this->r = r;
     this->colour = colour;
     this->score = score;
diff --git a/graph.h b/graph.h
index 0fb767d..73207f0 100644
--- a/graph.h
+++ b/graph.h
@@ -24,10 +24,11 @@ using std::list;
 class Vertex
 {
   public:
-    Vertex(int x, int y, int r, int colour = 0, int score = 0);
+    Vertex(int x, int y, int z, int r, int colour = 0, int score = 0);
 
     int x;
     int y;
+    int z;
     int r;
     int colour;
     int score;
@@ -45,10 +46,10 @@ class Graph
     list<Vertex*> get_vertices() const { return vertices; }
     list<Vertex*> get_colour(int colour);
 
-    bool point_in_vertex(int x, int y);
-    Vertex * vertex_at(int x, int y);
-    virtual bool add_vertex(int x, int y, int r, int colour = 0, int score = 0,
-			    Vertex* src=NULL);
+    bool point_in_vertex(int x, int y, int z);
+    Vertex * vertex_at(int x, int y, int z);
+    virtual bool add_vertex(int x, int y, int z, int r, int colour = 0,
+			    int score = 0, Vertex* src=NULL);
     void remove_vertex(Vertex* target);
 
     bool is_planar() const { return planar; }
@@ -58,7 +59,7 @@ class Graph
     list<Vertex*> vertices;
 
  private:
-    bool vertex_would_overlap(int x, int y, int r);
+    bool vertex_would_overlap(int x, int y, int z, int r);
     bool crosses_edge(Vertex* a, Vertex* b);
     bool planar;
 };
diff --git a/mathutils.cpp b/mathutils.cpp
index 069027f..7ae4bf9 100644
--- a/mathutils.cpp
+++ b/mathutils.cpp
@@ -1,11 +1,13 @@
 #include "mathutils.h"
 #include <math.h>
 
-float MathUtils::distance(float x1, float y1, float x2, float y2)
+float MathUtils::distance(float x1, float y1, float z1,
+			  float x2, float y2, float z2)
 {
-    float dy = y2 - y1;
     float dx = x2 - x1;
-    return sqrt(dy*dy + dx*dx);
+    float dy = y2 - y1;
+    float dz = z2 - z1;
+    return sqrt(dx*dx + dy*dy + dz*dz);
 }
 
 // Algorithm found at http://paulbourke.net/geometry/lineline2d/
diff --git a/mathutils.h b/mathutils.h
index aa4f0ab..936ce83 100644
--- a/mathutils.h
+++ b/mathutils.h
@@ -8,7 +8,8 @@ class MathUtils
 {
  public:
     // returns the cartesian distance of two points
-    static float distance(float x1, float y1, float x2, float y2);
+    static float distance(float x1, float y1, float z1, float x2, float y2,
+			  float z2);
 
     static bool lines_intersect(int x1, int y1, int x2, int y2,
 				int x3, int y3, int x4, int y4);