diff --git a/src/Life.java b/src/Life.java
index 84ab855..f676fb1 100644
--- a/src/Life.java
+++ b/src/Life.java
@@ -1,11 +1,20 @@
 public class Life implements ILife {
-  
+
+  private char[][] world = {
+          {'.', '.', '.', '.', '.'},
+          {'.', '.', '.', '.', '.'},
+          {'.', '.', '.', '.', '.'},
+          {'.', '.', '.', '.', '.'},
+          {'.', '.', '.', '.', '.'}
+  };
+  private char[][] newWorld = world;
+
   public static void main(String[] args) {
-    Life l = new Life(new String[] {  "     ",
-                                      "     ",
-                                      " *** ",
-                                      "     ",
-                                      "     " });
+    Life l = new Life(new String[] {  ".....",
+                                      ".....",
+                                      ".***.",
+                                      ".....",
+                                      "....." });
     l = (Life) l.nextGeneration();
   }
 
@@ -16,40 +25,87 @@ public class Life implements ILife {
 
   public Life(String[] setup) {
     this();
-    for (int y = 0; y < setup.length; y++)
-      for (int x = 0; x < setup[y].length(); x++)
-        if (setup[y].charAt(x) != ' ')
-          setAlive(x, y);
+
+    int x = 0;
+    int y;
+
+
+      for (y = 0; y < setup.length; y++) {
+        for (x = 0; x < setup[y].length(); x++) {
+          if (setup[y].charAt(x) != '.') {
+            world[x][y] = '*';
+          }
+        }
+      }
   }
 
 
   @Override
   public void nukeAll() {
-    // TODO Auto-generated method stub
+    for (int y = 0; y < world.length; y++)
+      for (int x = 0; x < world[y].length; x++) {
+          setDead(x, y);
+      }
 
   }
 
   @Override
   public void setAlive(int x, int y) {
-    // TODO Auto-generated method stub
+    newWorld [x][y] = '*';
 
   }
 
   @Override
   public void setDead(int x, int y) {
-    // TODO Auto-generated method stub
+      newWorld [x][y] = '.';
 
   }
 
   @Override
   public boolean isAlive(int x, int y) {
-    // TODO Auto-generated method stub
-    return false;
+    if(world[y][x] == '*'){
+      return true;
+    }
+    else return false;
   }
 
   @Override
   public ILife nextGeneration() {
-    // TODO Auto-generated method stub
-    return null;
+    String[] s = new String[newWorld.length];
+    checkNeighbors();
+    for(int y = 0; y < newWorld.length; y++){
+        s[y] = new String (newWorld[y]);
+      System.out.println(s[y]);
+    }
+    return new Life(s);
+  }
+
+  private void checkNeighbors(){
+    for (int y = 0; y < world.length; y++)
+      for (int x = 0; x < world[y].length; x++) {
+        if (!isAlive(x, y) && getNeighborCount(x, y) == 3) {
+          setAlive(x, y);
+        }
+        else if (isAlive(x, y) && getNeighborCount(x, y) <= 1){
+          setDead(x, y);
+        }
+        else if (isAlive(x, y) && getNeighborCount(x, y) >= 4){
+          setDead(x, y);
+        }
+        else{
+          newWorld[x][y] = world[x][y];
+        }
+      }
+  }
+
+  private int getNeighborCount(int x, int y){
+    int aliveNeighborCount = 0;
+    for(int i = -1; i<=1; i++) {
+      for (int j = -1; j<=1; j++) {
+        if(isAlive(x, y))
+          aliveNeighborCount++;
+      }
+    }
+    return aliveNeighborCount;
   }
 }
\ No newline at end of file
diff --git a/test/LifeTest.java b/test/LifeTest.java
index 3940e66..645f831 100644
--- a/test/LifeTest.java
+++ b/test/LifeTest.java
@@ -22,16 +22,49 @@ public class LifeTest {
 
     @Test
     public void destroyLonelyCell() {
+        //Arrange: eine lebende Zelle
+        Life l = new Life();
+        l.setAlive(1, 1);
+
+        //Act
+        ILife nextGen = l.nextGeneration();
+
+        //Assert: Zelle sollte jetzt tot sein
+        assertFalse(nextGen.isAlive(1,1));
     }
 
 
     @Test
     public void keepAliveCell() {
+        // Arrange: drei lebende Zellen
+        Life l = new Life();
+        l.setAlive(0, 0);
+        l.setAlive(0, 1);
+        l.setAlive(1, 0);
+
+        // Act: Berechnung der Folgegeneration
+        ILife nextGen = l.nextGeneration();
+
+        // Assert: Rasterpunkt mit zwei Nachbarn lebt noch
+        assertTrue(nextGen.isAlive(0, 1));
     }
 
 
     @Test
     public void destroyCrowdedCell() {
+        // Arrange: Zellblock
+        Life l = new Life();
+        l.setAlive(0, 0);
+        l.setAlive(0, 1);
+        l.setAlive(0, 2);
+        l.setAlive(1, 0);
+        l.setAlive(1, 1);
+
+        // Act: Berechnung der Folgegeneration
+        ILife nextGen = l.nextGeneration();
+
+        // Assert: Rasterpunkt mit vier Nachbarn ist tot
+        assertFalse(nextGen.isAlive(1, 1));
     }