diff --git a/chess/src/chess/Actor.java b/chess/src/chess/Actor.java
index f907b33..5044276 100644
--- a/chess/src/chess/Actor.java
+++ b/chess/src/chess/Actor.java
@@ -6,17 +6,26 @@ abstract class Actor {
     Boolean inCheck;   // Whether the Actor is currently in check.
     Boolean canCastle; // Whether the Actor can castle.
     Boolean won;       // Whether the Actor has won.
+    Board board;       // Reference to the board the actor is playing on.
 
-    Actor(Util.Col col, Boolean inCheck, Boolean canCastle, Boolean won) {
+    Actor(
+        Util.Col col, Boolean inCheck, Boolean canCastle, Boolean won,
+        Board board
+    ) {
         this.col = col;
         this.inCheck = inCheck;
         this.canCastle = canCastle;
         this.won = won;
+        this.board = board;
     }
 
     // Convenience constructor for start of game.
-    Actor(Util.Col col) {
+    Actor(Util.Col col, Board board) {
         this.col = col;
         this.inCheck = this.canCastle = this.won = false;
+        this.board = board;
     }
+
+    // Process a user click on the board if the active actor.
+    void click(Coord coord) {}
 }
diff --git a/chess/src/chess/Board.java b/chess/src/chess/Board.java
index 7602610..4a1fea0 100644
--- a/chess/src/chess/Board.java
+++ b/chess/src/chess/Board.java
@@ -1,4 +1,5 @@
 package chess;
+
 import java.awt.Color;
 import java.util.HashMap;
 import java.util.Map;
@@ -37,6 +38,14 @@ class Board {
 
     void set(Coord coord, Piece piece) { this.board.put(coord, piece); }
     Piece get(Coord coord) { return this.board.get(coord); }
+    void drop(Coord coord) { this.board.remove(coord); }
+
+    // Move a piece.
+    void move(Coord targ, Coord dest) {
+        Piece piece = this.get(targ);
+        this.drop(targ);
+        this.set(dest, piece);
+    }
 }
 
 // Measured from top left.
diff --git a/chess/src/chess/Bot.java b/chess/src/chess/Bot.java
index 426f192..0a20553 100644
--- a/chess/src/chess/Bot.java
+++ b/chess/src/chess/Bot.java
@@ -2,5 +2,5 @@ package chess;
 
 // A chess bot.
 class Bot extends Actor {
-    Bot(Util.Col col) { super(col); }
+    Bot(Util.Col col, Board board) { super(col, board); }
 }
diff --git a/chess/src/chess/Game.java b/chess/src/chess/Game.java
index 9629888..ad64268 100644
--- a/chess/src/chess/Game.java
+++ b/chess/src/chess/Game.java
@@ -1,24 +1,29 @@
 package chess;
 
-import chess.Util.Col;
 import javalib.impworld.*;
+import javalib.worldimages.*;
 
 class Game extends World {
     Actor white;
     Actor black;
     Board board;
     WorldScene scene;
+    Actor activeActor;
 
     Game(Actor white, Actor black, Board board) {
         this.white = white;
         this.black = black;
         this.board = board;
+        this.activeActor = this.white;
     }
 
     Game() {
-        this(
-            new Player(Util.Col.WHITE), new Player(Util.Col.BLACK), new Board()
-        );
+        this.board = new Board();
+
+        this.white = new Player(Util.Col.WHITE, this.board);
+        this.black = new Player(Util.Col.BLACK, this.board);
+
+        this.activeActor = this.white;
 
         this.setup();
     }
@@ -32,6 +37,7 @@ class Game extends World {
     void run() {
         this.bigBang(Util.boardW * Util.scale, Util.boardW * Util.scale, 0.01);
     }
+
     void draw() { this.scene = this.board.draw(); }
 
     void setup() {
@@ -101,4 +107,13 @@ class Game extends World {
             new Coord(7, 1).rel(Util.Col.WHITE), new Pawn(Util.Col.WHITE)
         );
     }
+
+    // Convert Posn (pixel coord) to Coord (board coord).
+    Coord where(Posn posn) {
+        return new Coord(posn.x / Util.scale, posn.y / Util.scale);
+    }
+
+    public void onMouseClicked(Posn posn) {
+        this.activeActor.click(this.where(posn));
+    }
 }
diff --git a/chess/src/chess/Player.java b/chess/src/chess/Player.java
index 86ba04d..9b6a958 100644
--- a/chess/src/chess/Player.java
+++ b/chess/src/chess/Player.java
@@ -2,5 +2,7 @@ package chess;
 
 // A human-controlled Actor.
 class Player extends Actor {
-    Player(Util.Col col) { super(col); }
+    Player(Util.Col col, Board board) { super(col, board); }
+
+    void click(Coord coord) { this.board.move(coord, new Coord(4, 4)); }
 }