diff --git a/Engine.Core/Collectors/ActiveBehaviourCollector.cs b/Engine.Core/Collectors/ActiveBehaviourCollector.cs
index f6a5fc0..dfe9a2f 100644
--- a/Engine.Core/Collectors/ActiveBehaviourCollector.cs
+++ b/Engine.Core/Collectors/ActiveBehaviourCollector.cs
@@ -1,148 +1,16 @@
 using System;
-using System.Collections.Generic;
 
 namespace Engine.Core;
 
-public class ActiveBehaviourCollector<T> : IBehaviourCollector<T> where T : class, IBehaviour
+public class ActiveBehaviourCollector<T> : ActiveBehaviourCollectorBase<T> where T : class, IBehaviour
 {
-    public Event<IBehaviourCollector<T>, IBehaviourCollector<T>.BehaviourCollectedArguments> OnCollected { get; } = new();
-    public Event<IBehaviourCollector<T>, IBehaviourCollector<T>.BehaviourRemovedArguments> OnRemoved { get; } = new();
-    public Event<IHasUniverse> OnUniverseAssigned { get; } = new();
-    public Event<IAssignable>? OnUnassigned { get; } = new();
-
-    private readonly Event<IBehaviourController, IBehaviourController.BehaviourAddedArguments>.EventHandler delegateOnBehaviourAdded = null!;
-    private readonly Event<IBehaviourController, IBehaviourController.BehaviourRemovedArguments>.EventHandler delegateOnBehaviourRemoved = null!;
-    private readonly Event<IActive, IActive.ActiveChangedArguments>.EventHandler delegateOnBehaviourStateChanged = null!;
-    private readonly Event<IUniverse, IUniverse.UniverseObjectRegisteredArguments>.EventHandler delegateOnUniverseObjectRegistered = null!;
-    private readonly Event<IUniverse, IUniverse.UniverseObjectUnRegisteredArguments>.EventHandler delegateOnUniverseObjectUnregistered = null!;
-
-    private readonly FastList<T> monitoringBehaviours = new(32);
     protected readonly FastList<T> activeBehaviours = new(32);
-    protected readonly Dictionary<IActive, T> monitoringActiveToBehaviour = new(32);
+    public override T this[Index index] => activeBehaviours[index];
+    public override int Count => activeBehaviours.Count;
 
-    public IUniverse Universe { get; private set; } = null!;
+    public ActiveBehaviourCollector() { }
+    public ActiveBehaviourCollector(IUniverse universe) : base(universe) { }
 
-    private void OnUniverseObjectRegistered(IUniverse manager, IUniverse.UniverseObjectRegisteredArguments args)
-    {
-        IUniverseObject universeObject = args.UniverseObjectRegistered;
-
-        universeObject.BehaviourController.OnBehaviourAdded.AddListener(delegateOnBehaviourAdded);
-        universeObject.BehaviourController.OnBehaviourRemoved.AddListener(delegateOnBehaviourRemoved);
-
-        for (int i = 0; i < universeObject.BehaviourController.Count; i++)
-            OnBehaviourAdded(universeObject.BehaviourController, new(universeObject.BehaviourController[i]));
-    }
-
-    private void OnUniverseObjectUnregistered(IUniverse manager, IUniverse.UniverseObjectUnRegisteredArguments args)
-    {
-        IUniverseObject universeObject = args.UniverseObjectUnregistered;
-
-        universeObject.BehaviourController.OnBehaviourAdded.RemoveListener(delegateOnBehaviourAdded);
-        universeObject.BehaviourController.OnBehaviourRemoved.RemoveListener(delegateOnBehaviourRemoved);
-
-        for (int i = 0; i < universeObject.BehaviourController.Count; i++)
-            OnBehaviourRemoved(universeObject.BehaviourController, new(universeObject.BehaviourController[i]));
-    }
-
-    protected virtual void OnBehaviourAdd(IBehaviour behaviour) { }
-    private void OnBehaviourAdded(IBehaviourController controller, IBehaviourController.BehaviourAddedArguments args)
-    {
-        if (args.BehaviourAdded is not T tBehaviour)
-            return;
-
-        monitoringBehaviours.Add(tBehaviour);
-        monitoringActiveToBehaviour.Add(tBehaviour, tBehaviour);
-        tBehaviour.OnActiveChanged.AddListener(delegateOnBehaviourStateChanged);
-        OnBehaviourStateChanged(tBehaviour, new(!tBehaviour.IsActive));
-    }
-
-    protected virtual void AddBehaviour(T behaviour) => activeBehaviours.Add(behaviour);
-    private void OnBehaviourStateChanged(IActive sender, IActive.ActiveChangedArguments args)
-    {
-        T behaviour = monitoringActiveToBehaviour[sender];
-        if (sender.IsActive)
-        {
-            AddBehaviour(behaviour);
-            OnBehaviourAdd(behaviour);
-            OnCollected?.Invoke(this, new(behaviour));
-        }
-        else if (activeBehaviours.Remove(behaviour))
-        {
-            OnBehaviourRemove(behaviour);
-            OnRemoved?.Invoke(this, new(behaviour));
-        }
-    }
-
-    protected virtual void OnBehaviourRemove(IBehaviour behaviour) { }
-    private void OnBehaviourRemoved(IBehaviourController controller, IBehaviourController.BehaviourRemovedArguments args)
-    {
-        if (args.BehaviourRemoved is not T tBehaviour)
-            return;
-
-        if (!monitoringBehaviours.Remove(tBehaviour) || !monitoringActiveToBehaviour.Remove(tBehaviour))
-            return;
-
-        tBehaviour.OnActiveChanged.RemoveListener(delegateOnBehaviourStateChanged);
-        if (activeBehaviours.Remove(tBehaviour))
-        {
-            OnBehaviourRemove(tBehaviour);
-            OnRemoved?.Invoke(this, new(tBehaviour));
-        }
-    }
-
-    public bool Assign(IUniverse universe)
-    {
-        if (Universe is not null)
-            return false;
-
-        foreach (IUniverseObject universeObject in universe.UniverseObjects)
-            OnUniverseObjectRegistered(universe, new(universeObject));
-
-        universe.OnUniverseObjectRegistered.AddListener(delegateOnUniverseObjectRegistered);
-        universe.OnUniverseObjectUnRegistered.AddListener(delegateOnUniverseObjectUnregistered);
-
-        Universe = universe;
-        OnUniverseAssigned?.Invoke(this);
-
-        return true;
-    }
-
-    public bool Unassign()
-    {
-        if (Universe is null)
-            return false;
-
-        foreach (IUniverseObject universeObject in Universe.UniverseObjects)
-            OnUniverseObjectUnregistered(Universe, new(universeObject));
-
-        Universe.OnUniverseObjectRegistered.RemoveListener(delegateOnUniverseObjectRegistered);
-        Universe.OnUniverseObjectUnRegistered.RemoveListener(delegateOnUniverseObjectUnregistered);
-
-        Universe = null!;
-        OnUnassigned?.Invoke(this);
-        return true;
-    }
-
-    public int Count => activeBehaviours.Count;
-    public T this[Index index] => activeBehaviours[index];
-
-    public ActiveBehaviourCollector()
-    {
-        delegateOnBehaviourAdded = OnBehaviourAdded;
-        delegateOnBehaviourRemoved = OnBehaviourRemoved;
-        delegateOnBehaviourStateChanged = OnBehaviourStateChanged;
-        delegateOnUniverseObjectRegistered = OnUniverseObjectRegistered;
-        delegateOnUniverseObjectUnregistered = OnUniverseObjectUnregistered;
-    }
-
-    public ActiveBehaviourCollector(IUniverse universe)
-    {
-        delegateOnBehaviourAdded = OnBehaviourAdded;
-        delegateOnBehaviourRemoved = OnBehaviourRemoved;
-        delegateOnBehaviourStateChanged = OnBehaviourStateChanged;
-        delegateOnUniverseObjectRegistered = OnUniverseObjectRegistered;
-        delegateOnUniverseObjectUnregistered = OnUniverseObjectUnregistered;
-
-        Assign(universe);
-    }
+    protected override void AddBehaviour(T behaviour) => activeBehaviours.Add(behaviour);
+    protected override bool RemoveBehaviour(T tBehaviour) => activeBehaviours.Remove(tBehaviour);
 }
diff --git a/Engine.Core/Collectors/ActiveBehaviourCollectorBase.cs b/Engine.Core/Collectors/ActiveBehaviourCollectorBase.cs
new file mode 100644
index 0000000..f389a61
--- /dev/null
+++ b/Engine.Core/Collectors/ActiveBehaviourCollectorBase.cs
@@ -0,0 +1,147 @@
+using System;
+using System.Collections.Generic;
+
+namespace Engine.Core;
+
+public abstract class ActiveBehaviourCollectorBase<T> : IBehaviourCollector<T> where T : class, IBehaviour
+{
+    protected readonly Dictionary<IActive, T> monitoringActiveToBehaviour = new(32);
+    protected readonly FastList<T> monitoringBehaviours = new(32);
+
+    private readonly Event<IBehaviourController, IBehaviourController.BehaviourAddedArguments>.EventHandler delegateOnBehaviourAdded = null!;
+    private readonly Event<IBehaviourController, IBehaviourController.BehaviourRemovedArguments>.EventHandler delegateOnBehaviourRemoved = null!;
+    private readonly Event<IActive, IActive.ActiveChangedArguments>.EventHandler delegateOnBehaviourStateChanged = null!;
+    private readonly Event<IUniverse, IUniverse.UniverseObjectRegisteredArguments>.EventHandler delegateOnUniverseObjectRegistered = null!;
+    private readonly Event<IUniverse, IUniverse.UniverseObjectUnRegisteredArguments>.EventHandler delegateOnUniverseObjectUnregistered = null!;
+
+    public Event<IBehaviourCollector<T>, IBehaviourCollector<T>.BehaviourCollectedArguments> OnCollected { get; } = new();
+    public Event<IBehaviourCollector<T>, IBehaviourCollector<T>.BehaviourRemovedArguments> OnRemoved { get; } = new();
+    public Event<IHasUniverse> OnUniverseAssigned { get; } = new();
+    public Event<IAssignable>? OnUnassigned { get; } = new();
+
+    public abstract int Count { get; }
+
+    public abstract T this[Index index] { get; }
+    public IUniverse Universe { get; private set; } = null!;
+
+    public bool Assign(IUniverse universe)
+    {
+        if (Universe is not null)
+            return false;
+
+        foreach (IUniverseObject universeObject in universe.UniverseObjects)
+            OnUniverseObjectRegistered(universe, new(universeObject));
+
+        universe.OnUniverseObjectRegistered.AddListener(delegateOnUniverseObjectRegistered);
+        universe.OnUniverseObjectUnRegistered.AddListener(delegateOnUniverseObjectUnregistered);
+
+        Universe = universe;
+        OnUniverseAssigned?.Invoke(this);
+
+        return true;
+    }
+
+    public bool Unassign()
+    {
+        if (Universe is null)
+            return false;
+
+        foreach (IUniverseObject universeObject in Universe.UniverseObjects)
+            OnUniverseObjectUnregistered(Universe, new(universeObject));
+
+        Universe.OnUniverseObjectRegistered.RemoveListener(delegateOnUniverseObjectRegistered);
+        Universe.OnUniverseObjectUnRegistered.RemoveListener(delegateOnUniverseObjectUnregistered);
+
+        Universe = null!;
+        OnUnassigned?.Invoke(this);
+        return true;
+    }
+
+    protected abstract void AddBehaviour(T behaviour);
+    protected virtual void OnBehaviourAdd(IBehaviour behaviour) { }
+    private void OnBehaviourAdded(IBehaviourController controller, IBehaviourController.BehaviourAddedArguments args)
+    {
+        if (args.BehaviourAdded is not T tBehaviour)
+            return;
+
+        monitoringBehaviours.Add(tBehaviour);
+        monitoringActiveToBehaviour.Add(tBehaviour, tBehaviour);
+        tBehaviour.OnActiveChanged.AddListener(delegateOnBehaviourStateChanged);
+        OnBehaviourStateChanged(tBehaviour, new(!tBehaviour.IsActive));
+    }
+
+    protected abstract bool RemoveBehaviour(T behaviour);
+    protected virtual void OnBehaviourRemove(IBehaviour behaviour) { }
+    private void OnBehaviourRemoved(IBehaviourController controller, IBehaviourController.BehaviourRemovedArguments args)
+    {
+        if (args.BehaviourRemoved is not T tBehaviour)
+            return;
+
+        if (!monitoringBehaviours.Remove(tBehaviour) || !monitoringActiveToBehaviour.Remove(tBehaviour))
+            return;
+
+        tBehaviour.OnActiveChanged.RemoveListener(delegateOnBehaviourStateChanged);
+        if (!RemoveBehaviour(tBehaviour))
+            return;
+
+        OnBehaviourRemove(tBehaviour);
+        OnRemoved?.Invoke(this, new(tBehaviour));
+    }
+    private void OnBehaviourStateChanged(IActive sender, IActive.ActiveChangedArguments args)
+    {
+        T behaviour = monitoringActiveToBehaviour[sender];
+        if (sender.IsActive)
+        {
+            AddBehaviour(behaviour);
+            OnBehaviourAdd(behaviour);
+            OnCollected?.Invoke(this, new(behaviour));
+        }
+        else if (RemoveBehaviour(behaviour))
+        {
+            OnBehaviourRemove(behaviour);
+            OnRemoved?.Invoke(this, new(behaviour));
+        }
+    }
+
+    private void OnUniverseObjectRegistered(IUniverse manager, IUniverse.UniverseObjectRegisteredArguments args)
+    {
+        IUniverseObject universeObject = args.UniverseObjectRegistered;
+
+        universeObject.BehaviourController.OnBehaviourAdded.AddListener(delegateOnBehaviourAdded);
+        universeObject.BehaviourController.OnBehaviourRemoved.AddListener(delegateOnBehaviourRemoved);
+
+        for (int i = 0; i < universeObject.BehaviourController.Count; i++)
+            OnBehaviourAdded(universeObject.BehaviourController, new(universeObject.BehaviourController[i]));
+    }
+
+    private void OnUniverseObjectUnregistered(IUniverse manager, IUniverse.UniverseObjectUnRegisteredArguments args)
+    {
+        IUniverseObject universeObject = args.UniverseObjectUnregistered;
+
+        universeObject.BehaviourController.OnBehaviourAdded.RemoveListener(delegateOnBehaviourAdded);
+        universeObject.BehaviourController.OnBehaviourRemoved.RemoveListener(delegateOnBehaviourRemoved);
+
+        for (int i = 0; i < universeObject.BehaviourController.Count; i++)
+            OnBehaviourRemoved(universeObject.BehaviourController, new(universeObject.BehaviourController[i]));
+    }
+
+    public ActiveBehaviourCollectorBase()
+    {
+        delegateOnBehaviourAdded = OnBehaviourAdded;
+        delegateOnBehaviourRemoved = OnBehaviourRemoved;
+        delegateOnBehaviourStateChanged = OnBehaviourStateChanged;
+        delegateOnUniverseObjectRegistered = OnUniverseObjectRegistered;
+        delegateOnUniverseObjectUnregistered = OnUniverseObjectUnregistered;
+    }
+
+    public ActiveBehaviourCollectorBase(IUniverse universe)
+    {
+        delegateOnBehaviourAdded = OnBehaviourAdded;
+        delegateOnBehaviourRemoved = OnBehaviourRemoved;
+        delegateOnBehaviourStateChanged = OnBehaviourStateChanged;
+        delegateOnUniverseObjectRegistered = OnUniverseObjectRegistered;
+        delegateOnUniverseObjectUnregistered = OnUniverseObjectUnregistered;
+
+        Assign(universe);
+    }
+}