Because some people really wanted to disable this,

mostly due to clientside lag.

src/main/java/com/gmail/nossr50/config/Config.java

@@ -115,6 +115,7 @@ public class Config extends AutoUpdateConfigLoader {
     public boolean getDodgeEffectEnabled() { return config.getBoolean("Particles.Dodge", true); }
     public boolean getBleedEffectEnabled() { return config.getBoolean("Particles.Bleed", true); }
     public boolean getGreaterImpactEffectEnabled() { return config.getBoolean("Particles.Greater_Impact", true); }
+    public boolean getLevelUpEffectsEnabled() { return config.getBoolean("Particles.LevelUp", true); }
 
     /* PARTY SETTINGS */
     public int getAutoPartyKickInterval() { return config.getInt("Party.AutoKick_Interval", 12); }

src/main/java/com/gmail/nossr50/listeners/SelfListener.java

@@ -6,12 +6,17 @@ import org.bukkit.event.EventHandler;
 import org.bukkit.event.EventPriority;
 import org.bukkit.event.Listener;
 
+import com.gmail.nossr50.config.Config;
 import com.gmail.nossr50.events.experience.McMMOPlayerLevelUpEvent;
 import com.gmail.nossr50.util.skills.ParticleEffectUtils;
 
 public class SelfListener implements Listener {
     @EventHandler(priority = EventPriority.MONITOR, ignoreCancelled = true)
     public void onPlayerLevelUp(McMMOPlayerLevelUpEvent event) {
+        if (!Config.getInstance().getLevelUpEffectsEnabled()) {
+            return;
+        }
+
         Calendar today = Calendar.getInstance();
         if (today.get(Calendar.MONTH) == Calendar.APRIL && today.get(Calendar.DAY_OF_MONTH) == 1) {
             ParticleEffectUtils.runescapeModeCelebration(event.getPlayer(), event.getSkill());

src/main/resources/config.yml

@@ -368,8 +368,10 @@ Particles:
     # These settings determine if fireworks should get launched when a player activates/deactivates an ability
     Ability_Activation: true
     Ability_Deactivation: true
-    
+
     # Use particle effect when these abilities trigger
     Dodge: true
     Bleed: true
     Greater_Impact: true
+
+    LevelUp: true