diff --git a/src/main/java/de/bixilon/minosoft/data/entities/StatusEffectInstance.kt b/src/main/java/de/bixilon/minosoft/data/entities/StatusEffectInstance.kt
index 6a0f17d03..82a126966 100644
--- a/src/main/java/de/bixilon/minosoft/data/entities/StatusEffectInstance.kt
+++ b/src/main/java/de/bixilon/minosoft/data/entities/StatusEffectInstance.kt
@@ -18,4 +18,10 @@ data class StatusEffectInstance(
     val statusEffect: StatusEffect,
     val amplifier: Int,
     val duration: Int,
-)
+) {
+    private val startMillis = System.currentTimeMillis()
+
+    val remainingMillis: Long
+        get() = System.currentTimeMillis() - startMillis
+}
+
diff --git a/src/main/java/de/bixilon/minosoft/data/entities/entities/Entity.kt b/src/main/java/de/bixilon/minosoft/data/entities/entities/Entity.kt
index 60891f99d..ce6af3dfe 100644
--- a/src/main/java/de/bixilon/minosoft/data/entities/entities/Entity.kt
+++ b/src/main/java/de/bixilon/minosoft/data/entities/entities/Entity.kt
@@ -31,6 +31,7 @@ import de.bixilon.minosoft.gui.rendering.util.VecUtil.chunkPosition
 import de.bixilon.minosoft.gui.rendering.util.VecUtil.inChunkPosition
 import de.bixilon.minosoft.protocol.network.connection.PlayConnection
 import de.bixilon.minosoft.protocol.protocol.ProtocolDefinition
+import de.bixilon.minosoft.util.KUtil.synchronizedMapOf
 import glm_.vec3.Vec3
 import java.lang.reflect.InvocationTargetException
 import java.util.*
@@ -42,8 +43,8 @@ abstract class Entity(
     var position: Vec3,
     var rotation: EntityRotation,
 ) {
-    val equipment: MutableMap<EquipmentSlots, ItemStack> = mutableMapOf()
-    val effectList: MutableSet<StatusEffectInstance> = mutableSetOf()
+    val equipment: MutableMap<EquipmentSlots, ItemStack> = synchronizedMapOf()
+    val activeStatusEffects: MutableMap<StatusEffect, StatusEffectInstance> = synchronizedMapOf()
 
     @JvmField
     protected val versionId: Int = connection.version.versionId
@@ -69,12 +70,11 @@ abstract class Entity(
 
     fun addEffect(effect: StatusEffectInstance) {
         // effect already applied, maybe the duration or the amplifier changed?
-        effectList.removeIf { (statusEffect) -> statusEffect === effect.statusEffect }
-        effectList.add(effect)
+        activeStatusEffects[effect.statusEffect] = effect
     }
 
     fun removeEffect(effect: StatusEffect) {
-        effectList.removeIf { (statusEffect) -> statusEffect === effect }
+        activeStatusEffects.remove(effect)
     }
 
     fun attachTo(vehicleId: Int?) {
@@ -278,7 +278,7 @@ abstract class Entity(
         return delta
     }
 
-    fun tick(deltaMillis: Long) {
+    private fun tickMovement(deltaMillis: Long) {
         if (connection.world.getChunk(position.blockPosition.chunkPosition)?.isFullyLoaded != true) {
             return // ignore update if chunk is not loaded yet
         }
@@ -301,6 +301,12 @@ abstract class Entity(
         move(velocity * deltaTime)
     }
 
+    fun tick(deltaMillis: Long) {
+        check(deltaMillis > 0L) { "Delta tick time is <= 0: $deltaMillis" }
+
+        tickMovement(deltaMillis)
+    }
+
     private val aabb: AABB
         get() = defaultAABB + position
 
diff --git a/src/main/java/de/bixilon/minosoft/data/entities/meta/EntityMetaData.kt b/src/main/java/de/bixilon/minosoft/data/entities/meta/EntityMetaData.kt
index ad573d5f1..e37255f9c 100644
--- a/src/main/java/de/bixilon/minosoft/data/entities/meta/EntityMetaData.kt
+++ b/src/main/java/de/bixilon/minosoft/data/entities/meta/EntityMetaData.kt
@@ -40,6 +40,10 @@ class EntityMetaData(
 ) {
     val sets: MetaDataHashMap = MetaDataHashMap()
 
+    override fun toString(): String {
+        return sets.toString()
+    }
+
     fun getData(type: EntityMetaDataDataTypes, buffer: PlayInByteBuffer): Any? {
         return when (type) {
             EntityMetaDataDataTypes.BYTE -> buffer.readByte()
@@ -128,8 +132,8 @@ class EntityMetaData(
             get(index)?.let {
                 try {
                     return it as K
-                } catch (e: ClassCastException) {
-                    Log.log(LogMessageType.OTHER, level = LogLevels.WARN, message = e)
+                } catch (exception: ClassCastException) {
+                    Log.log(LogMessageType.OTHER, level = LogLevels.WARN, message = exception)
                 }
             }
             return field.getDefaultValue()
@@ -197,7 +201,7 @@ class EntityMetaData(
         }
 
         fun getChatComponent(field: EntityMetaDataFields): ChatComponent? {
-            return ChatComponent.of(get(field), connection.version.localeManager)
+            return get<Any?>(field)?.let { ChatComponent.of(it, connection.version.localeManager) }
         }
 
         fun getString(field: EntityMetaDataFields): String? {
diff --git a/src/main/java/de/bixilon/minosoft/data/inventory/ItemStack.kt b/src/main/java/de/bixilon/minosoft/data/inventory/ItemStack.kt
index 92d0112ea..f69afd8fd 100644
--- a/src/main/java/de/bixilon/minosoft/data/inventory/ItemStack.kt
+++ b/src/main/java/de/bixilon/minosoft/data/inventory/ItemStack.kt
@@ -161,11 +161,6 @@ data class ItemStack(
             return nbt
         }
 
-
-    override fun toString(): String {
-        return fullDisplayName
-    }
-
     val displayName: ChatComponent
         get() {
             customDisplayName?.let { return it }
@@ -173,10 +168,6 @@ data class ItemStack(
             return ChatComponent.of(item.toString())
         }
 
-    // ToDo all properties
-    val fullDisplayName: String
-        get() = displayName.legacyText + ": " + super.toString()
-
     fun shouldHideEnchantments(): Boolean {
         return BitByte.isBitSet(hideFlags, HIDE_ENCHANTMENT_BIT)
     }
diff --git a/src/main/java/de/bixilon/minosoft/data/world/WorldEntities.kt b/src/main/java/de/bixilon/minosoft/data/world/WorldEntities.kt
index 1775f72d3..e68653833 100644
--- a/src/main/java/de/bixilon/minosoft/data/world/WorldEntities.kt
+++ b/src/main/java/de/bixilon/minosoft/data/world/WorldEntities.kt
@@ -15,6 +15,7 @@ package de.bixilon.minosoft.data.world
 
 import de.bixilon.minosoft.data.entities.entities.Entity
 import de.bixilon.minosoft.util.KUtil.synchronizedMapOf
+import de.bixilon.minosoft.util.KUtil.toSynchronizedMap
 import java.util.*
 
 class WorldEntities : Iterable<Entity> {
@@ -72,6 +73,6 @@ class WorldEntities : Iterable<Entity> {
     }
 
     override fun iterator(): Iterator<Entity> {
-        return idEntityMap.values.iterator()
+        return idEntityMap.toSynchronizedMap().values.iterator()
     }
 }
diff --git a/src/main/java/de/bixilon/minosoft/protocol/network/connection/PlayConnection.kt b/src/main/java/de/bixilon/minosoft/protocol/network/connection/PlayConnection.kt
index bec15c7b3..f6bb11dfd 100644
--- a/src/main/java/de/bixilon/minosoft/protocol/network/connection/PlayConnection.kt
+++ b/src/main/java/de/bixilon/minosoft/protocol/network/connection/PlayConnection.kt
@@ -117,10 +117,12 @@ class PlayConnection(
                     velocityHandlerTask = TimeWorkerTask(ProtocolDefinition.TICK_TIME / 5) {
                         val currentTime = System.currentTimeMillis()
                         val deltaTime = currentTime - velocityHandlerLastExecutionTime
-                        for (entity in world.entities) {
-                            entity.tick(deltaTime)
+                        if (deltaTime > 0L) {
+                            for (entity in world.entities) {
+                                entity.tick(deltaTime)
+                            }
+                            renderer?.renderWindow?.inputHandler?.camera?.checkPosition()
                         }
-                        renderer?.renderWindow?.inputHandler?.camera?.checkPosition()
                         velocityHandlerLastExecutionTime = currentTime
                     }
                     TimeWorker.addTask(velocityHandlerTask)
diff --git a/src/main/java/de/bixilon/minosoft/terminal/commands/commands/CommandEntities.java b/src/main/java/de/bixilon/minosoft/terminal/commands/commands/CommandEntities.java
index 11c326536..06ab29c0d 100644
--- a/src/main/java/de/bixilon/minosoft/terminal/commands/commands/CommandEntities.java
+++ b/src/main/java/de/bixilon/minosoft/terminal/commands/commands/CommandEntities.java
@@ -55,7 +55,7 @@ public class CommandEntities extends Command {
                             tableData.add(new Object[]{"Location", entity.getPosition()});
                             tableData.add(new Object[]{"Rotation", entity.getRotation()});
                             tableData.add(new Object[]{"Equipment", entity.getEquipment()});
-                            tableData.add(new Object[]{"Effects", entity.getEffectList()});
+                            tableData.add(new Object[]{"Effects", entity.getActiveStatusEffects()});
                             tableData.add(new Object[]{"Attached to", entity.getAttachedEntity() == -1 ? "" : entity.getAttachedEntity()});
 
                             for (var entry : entity.getEntityMetaDataFormatted().entrySet()) {
diff --git a/src/main/java/de/bixilon/minosoft/util/time/TimeWorker.kt b/src/main/java/de/bixilon/minosoft/util/time/TimeWorker.kt
index b60369014..02eafaf9f 100644
--- a/src/main/java/de/bixilon/minosoft/util/time/TimeWorker.kt
+++ b/src/main/java/de/bixilon/minosoft/util/time/TimeWorker.kt
@@ -1,20 +1,25 @@
 package de.bixilon.minosoft.util.time
 
 import de.bixilon.minosoft.Minosoft
-import de.bixilon.minosoft.util.KUtil.synchronizedListOf
-import de.bixilon.minosoft.util.KUtil.toSynchronizedList
+import de.bixilon.minosoft.util.KUtil.synchronizedSetOf
+import de.bixilon.minosoft.util.KUtil.toSynchronizedSet
 
 object TimeWorker {
-    private val TASKS: MutableList<TimeWorkerTask> = synchronizedListOf()
+    private val TASKS: MutableSet<TimeWorkerTask> = synchronizedSetOf()
 
     init {
         Thread({
             while (true) {
                 val currentTime = System.currentTimeMillis()
-                for (task in TASKS.toSynchronizedList()) {
-                    if (currentTime - task.lastExecution >= task.interval) {
-                        Minosoft.THREAD_POOL.execute(task.runnable)
-                        task.lastExecution = currentTime
+                for (task in TASKS.toSynchronizedSet()) {
+                    if (!task.getsExecuted && currentTime - task.lastExecution >= task.interval) {
+                        Minosoft.THREAD_POOL.execute {
+                            task.getsExecuted = true
+                            task.runnable.run()
+                            task.lastExecution = currentTime
+                            task.getsExecuted = false
+                        }
+                        TASKS -= task
                     }
                 }
                 Thread.sleep(1)
@@ -22,6 +27,16 @@ object TimeWorker {
         }, "TimeWorkerThread").start()
     }
 
+    fun runIn(millis: Int, runnable: Runnable) {
+        val task = TimeWorkerTask(
+            interval = millis,
+            runnable = runnable,
+            runOnce = true,
+        )
+        task.lastExecution = System.currentTimeMillis()
+        TASKS += task
+    }
+
     fun addTask(task: TimeWorkerTask) {
         TASKS += task
     }
diff --git a/src/main/java/de/bixilon/minosoft/util/time/TimeWorkerTask.kt b/src/main/java/de/bixilon/minosoft/util/time/TimeWorkerTask.kt
index 22fb5077a..0361d02a6 100644
--- a/src/main/java/de/bixilon/minosoft/util/time/TimeWorkerTask.kt
+++ b/src/main/java/de/bixilon/minosoft/util/time/TimeWorkerTask.kt
@@ -2,7 +2,9 @@ package de.bixilon.minosoft.util.time
 
 data class TimeWorkerTask(
     val interval: Int,
+    val runOnce: Boolean = true,
     val runnable: Runnable,
 ) {
+    var getsExecuted: Boolean = false
     var lastExecution: Long = 0L
 }