diff --git a/src/main/java/eu/m724/giants/Configuration.java b/src/main/java/eu/m724/giants/Configuration.java
index 68b3153..f7bbed6 100644
--- a/src/main/java/eu/m724/giants/Configuration.java
+++ b/src/main/java/eu/m724/giants/Configuration.java
@@ -10,6 +10,7 @@ import org.bukkit.util.Vector;
 
 import java.io.File;
 import java.util.HashSet;
+import java.util.List;
 import java.util.Set;
 import java.util.logging.Logger;
 
@@ -26,6 +27,7 @@ public class Configuration {
 
     Vector attackReach;
 
+    List<String> worldBlacklist;
     Set<PotionEffect> effects = new HashSet<>();
     Set<Drop> drops = new HashSet<>();
 
@@ -48,6 +50,8 @@ public class Configuration {
         double _expandUp = config.getDouble("expandUp");
         attackReach = new Vector(_attackReach, _expandUp, _attackReach);
 
+        worldBlacklist = config.getStringList("blacklist");
+
         for (String line : config.getStringList("effects")) {
             String[] parts = line.split(":");
 
diff --git a/src/main/java/eu/m724/giants/GiantProcessor.java b/src/main/java/eu/m724/giants/GiantProcessor.java
index 118eb10..d5b3643 100644
--- a/src/main/java/eu/m724/giants/GiantProcessor.java
+++ b/src/main/java/eu/m724/giants/GiantProcessor.java
@@ -132,6 +132,9 @@ public class GiantProcessor implements Listener {
 
     @EventHandler
     public void entitySpawn(EntitySpawnEvent e) {
+        if (configuration.worldBlacklist.contains(e.getLocation().getWorld().getName()))
+            return;
+
         if (e.getEntityType() == EntityType.ZOMBIE) {
             if (configuration.chance > random.nextFloat()) {
                 e.setCancelled(true);
diff --git a/src/main/resources/config.yml b/src/main/resources/config.yml
index 7ddb714..099a4ed 100644
--- a/src/main/resources/config.yml
+++ b/src/main/resources/config.yml
@@ -1,5 +1,5 @@
-# Do as it says
-remove_this_line_after_editing: true
+# Notes:
+# To have no values in a list, remove every value below it and change to [] like `effects: []`
 
 # If disabled, the giant won't move (but it will still attack)
 ai: true
@@ -18,30 +18,34 @@ attackDelay: 20
 # There's no wall check yet, so it will hit through walls
 attackReach: 2
 
+# The value above does not modify vertical reach, this value extends it upwards
+expandUp: 0
+
 ###
 
 # Chance of a zombie becoming a giant. This is per each zombie spawn, natural or not.
-chance: 0.02
+# 0 is 0% (no zombie becomes a giant), 1 is 100% (every zombie becomes a giant), so the default 0.005 is 0.5%
+chance: 0.005
+
+# Which worlds not to spawn Giants in
+blacklist:
+  - "world_nether"
+  - "world_the_end"
 
 # Potion effects applied to a giant
 # type:amplifier
 # types: https://hub.spigotmc.org/javadocs/spigot/org/bukkit/potion/PotionEffectType.html
 # amplifier: just like you know it, max 255
-# Set to [] to disable
 effects:
-- "JUMP:1"
-- "REGENERATION:2"
-- "HEALTH_BOOST:10"
+  - "JUMP:1"
+  - "REGENERATION:2"
+  - "HEALTH_BOOST:10"
 
 # Custom drops
 # material:min quantity:max quantity:chance
 # material: https://hub.spigotmc.org/javadocs/spigot/org/bukkit/Material.html
 # min and max are inclusive
-# chance is 0 - 100
+# unlike above, chance is an integer from 0 to 100
 # metadata can't be set yet
-# Set to [] to disable
 drops:
-- "APPLE:1:3:25" # 25% of the time, drop 1 to 3 apples
-
-### Advanced
-expandUp: 0
\ No newline at end of file
+  - "APPLE:1:3:25" # 25% of the time, drop 1 to 3 apples