diff --git a/index.html b/index.html
index 91b17fb..823ae6e 100644
--- a/index.html
+++ b/index.html
@@ -12,6 +12,10 @@
             <div class="tools">
                 <button id="sand-btn" class="active">Sand</button>
                 <button id="water-btn">Water</button>
+                <button id="dirt-btn">Dirt</button>
+                <button id="stone-btn">Stone</button>
+                <button id="grass-btn">Grass</button>
+                <button id="wood-btn">Wood</button>
                 <button id="eraser-btn">Eraser</button>
             </div>
             <div class="navigation">
diff --git a/script.js b/script.js
index 14a98e6..bb67325 100644
--- a/script.js
+++ b/script.js
@@ -6,12 +6,20 @@ const WATER_SPREAD = 3;
 const SAND_COLOR = '#e6c588';
 const WATER_COLOR = '#4a80f5';
 const WALL_COLOR = '#888888';
+const DIRT_COLOR = '#8B4513';
+const STONE_COLOR = '#A9A9A9';
+const GRASS_COLOR = '#7CFC00';
+const WOOD_COLOR = '#8B5A2B';
 
 // Element types
 const EMPTY = 0;
 const SAND = 1;
 const WATER = 2;
 const WALL = 3;
+const DIRT = 4;
+const STONE = 5;
+const GRASS = 6;
+const WOOD = 7;
 
 // Global variables
 let canvas, ctx;
@@ -41,6 +49,10 @@ window.onload = function() {
     // Tool selection
     document.getElementById('sand-btn').addEventListener('click', () => setTool(SAND));
     document.getElementById('water-btn').addEventListener('click', () => setTool(WATER));
+    document.getElementById('dirt-btn').addEventListener('click', () => setTool(DIRT));
+    document.getElementById('stone-btn').addEventListener('click', () => setTool(STONE));
+    document.getElementById('grass-btn').addEventListener('click', () => setTool(GRASS));
+    document.getElementById('wood-btn').addEventListener('click', () => setTool(WOOD));
     document.getElementById('eraser-btn').addEventListener('click', () => setTool(EMPTY));
     
     // Navigation controls
@@ -81,6 +93,14 @@ function setTool(tool) {
         document.getElementById('sand-btn').classList.add('active');
     } else if (tool === WATER) {
         document.getElementById('water-btn').classList.add('active');
+    } else if (tool === DIRT) {
+        document.getElementById('dirt-btn').classList.add('active');
+    } else if (tool === STONE) {
+        document.getElementById('stone-btn').classList.add('active');
+    } else if (tool === GRASS) {
+        document.getElementById('grass-btn').classList.add('active');
+    } else if (tool === WOOD) {
+        document.getElementById('wood-btn').classList.add('active');
     } else if (tool === EMPTY) {
         document.getElementById('eraser-btn').classList.add('active');
     }
@@ -317,7 +337,7 @@ function updatePhysics() {
                 const index = y * CHUNK_SIZE + x;
                 const type = chunk[index];
                 
-                if (type === EMPTY) continue;
+                if (type === EMPTY || type === STONE || type === WOOD) continue;
                 
                 const worldX = chunkX * CHUNK_SIZE + x;
                 const worldY = chunkY * CHUNK_SIZE + y;
@@ -326,6 +346,10 @@ function updatePhysics() {
                     updateSand(worldX, worldY);
                 } else if (type === WATER) {
                     updateWater(worldX, worldY);
+                } else if (type === DIRT) {
+                    updateDirt(worldX, worldY);
+                } else if (type === GRASS) {
+                    updateGrass(worldX, worldY);
                 }
             }
         }
@@ -354,6 +378,71 @@ function updateSand(x, y) {
     }
 }
 
+function updateDirt(x, y) {
+    // Try to move down
+    if (getPixel(x, y + 1) === EMPTY) {
+        setPixel(x, y, EMPTY);
+        setPixel(x, y + 1, DIRT);
+    } 
+    // Try to move down-left or down-right
+    else if (getPixel(x - 1, y + 1) === EMPTY) {
+        setPixel(x, y, EMPTY);
+        setPixel(x - 1, y + 1, DIRT);
+    } 
+    else if (getPixel(x + 1, y + 1) === EMPTY) {
+        setPixel(x, y, EMPTY);
+        setPixel(x + 1, y + 1, DIRT);
+    }
+    // Dirt can displace water
+    else if (getPixel(x, y + 1) === WATER) {
+        setPixel(x, y, WATER);
+        setPixel(x, y + 1, DIRT);
+    }
+    
+    // Dirt can turn into grass if exposed to air above
+    if (getPixel(x, y - 1) === EMPTY && Math.random() < 0.001) {
+        setPixel(x, y, GRASS);
+    }
+}
+
+function updateGrass(x, y) {
+    // Grass behaves like dirt for physics
+    if (getPixel(x, y + 1) === EMPTY) {
+        setPixel(x, y, EMPTY);
+        setPixel(x, y + 1, GRASS);
+    } 
+    else if (getPixel(x - 1, y + 1) === EMPTY) {
+        setPixel(x, y, EMPTY);
+        setPixel(x - 1, y + 1, GRASS);
+    } 
+    else if (getPixel(x + 1, y + 1) === EMPTY) {
+        setPixel(x, y, EMPTY);
+        setPixel(x + 1, y + 1, GRASS);
+    }
+    else if (getPixel(x, y + 1) === WATER) {
+        setPixel(x, y, WATER);
+        setPixel(x, y + 1, GRASS);
+    }
+    
+    // Grass can spread to nearby dirt
+    if (Math.random() < 0.0005) {
+        const directions = [
+            {dx: -1, dy: 0}, {dx: 1, dy: 0}, 
+            {dx: 0, dy: -1}, {dx: 0, dy: 1}
+        ];
+        
+        const dir = directions[Math.floor(Math.random() * directions.length)];
+        if (getPixel(x + dir.dx, y + dir.dy) === DIRT) {
+            setPixel(x + dir.dx, y + dir.dy, GRASS);
+        }
+    }
+    
+    // Grass dies if covered (no air above)
+    if (getPixel(x, y - 1) !== EMPTY && Math.random() < 0.05) {
+        setPixel(x, y, DIRT);
+    }
+}
+
 function updateWater(x, y) {
     // Try to move down
     if (getPixel(x, y + 1) === EMPTY) {
@@ -472,6 +561,14 @@ function render() {
                     ctx.fillStyle = WATER_COLOR;
                 } else if (type === WALL) {
                     ctx.fillStyle = WALL_COLOR;
+                } else if (type === DIRT) {
+                    ctx.fillStyle = DIRT_COLOR;
+                } else if (type === STONE) {
+                    ctx.fillStyle = STONE_COLOR;
+                } else if (type === GRASS) {
+                    ctx.fillStyle = GRASS_COLOR;
+                } else if (type === WOOD) {
+                    ctx.fillStyle = WOOD_COLOR;
                 }
                 
                 // Draw the pixel