diff --git a/src/com/massivecraft/mcore4/MCore.java b/src/com/massivecraft/mcore4/MCore.java
index 2f5bdfbf..fb150ae6 100644
--- a/src/com/massivecraft/mcore4/MCore.java
+++ b/src/com/massivecraft/mcore4/MCore.java
@@ -47,7 +47,7 @@ public class MCore extends MPlugin
 	// CONSTRUCT
 	// -------------------------------------------- //
 	
-	protected static MCore p;
+	public static MCore p;
 	public MCore()
 	{
 		p = this;
diff --git a/src/com/massivecraft/mcore4/cmd/arg/AHPlayerWrapperNew.java b/src/com/massivecraft/mcore4/cmd/arg/AHPlayerWrapperColl.java
similarity index 89%
rename from src/com/massivecraft/mcore4/cmd/arg/AHPlayerWrapperNew.java
rename to src/com/massivecraft/mcore4/cmd/arg/AHPlayerWrapperColl.java
index 994e9749..5c79a108 100644
--- a/src/com/massivecraft/mcore4/cmd/arg/AHPlayerWrapperNew.java
+++ b/src/com/massivecraft/mcore4/cmd/arg/AHPlayerWrapperColl.java
@@ -9,12 +9,12 @@ import com.massivecraft.mcore4.store.Coll;
 import com.massivecraft.mcore4.util.PlayerUtil;
 import com.massivecraft.mcore4.util.Txt;
 
-public class AHPlayerWrapperNew<E> extends AHBase<E>
+public class AHPlayerWrapperColl<E> extends AHBase<E>
 {
 	final Coll<E, ?> coll;
 	public Coll<E, ?> coll() { return this.coll; };
 	
-	public AHPlayerWrapperNew(Coll<E, ?> coll)
+	public AHPlayerWrapperColl(Coll<E, ?> coll)
 	{
 		this.coll = coll;
 	}
diff --git a/src/com/massivecraft/mcore4/cmd/arg/AHPlayerWrapperColls.java b/src/com/massivecraft/mcore4/cmd/arg/AHPlayerWrapperColls.java
new file mode 100644
index 00000000..e448e35b
--- /dev/null
+++ b/src/com/massivecraft/mcore4/cmd/arg/AHPlayerWrapperColls.java
@@ -0,0 +1,28 @@
+package com.massivecraft.mcore4.cmd.arg;
+
+import org.bukkit.command.CommandSender;
+
+import com.massivecraft.mcore4.MPlugin;
+import com.massivecraft.mcore4.store.Coll;
+import com.massivecraft.mcore4.store.Colls;
+public class AHPlayerWrapperColls<E> extends AHBase<E>
+{
+	protected final Colls<Coll<E, ?>, E, ?> colls;
+	public Colls<Coll<E, ?>, E, ?> colls() { return this.colls; };
+	
+	@SuppressWarnings("unchecked")
+	public AHPlayerWrapperColls(Object colls)
+	{
+		this.colls = (Colls<Coll<E, ?>, E, ?>) colls;
+	}
+	
+	@Override
+	public E parse(String str, String style, CommandSender sender, MPlugin p)
+	{
+		Coll<E, ?> coll = colls.get(sender);
+		AHPlayerWrapperColl<E> ahinner = new AHPlayerWrapperColl<E>(coll);
+		E ret = ahinner.parse(str, style, sender, p);
+		this.error.addAll(ahinner.error);
+		return ret;
+	}
+}
diff --git a/src/com/massivecraft/mcore4/store/Coll.java b/src/com/massivecraft/mcore4/store/Coll.java
index c02681bf..caa7dd39 100644
--- a/src/com/massivecraft/mcore4/store/Coll.java
+++ b/src/com/massivecraft/mcore4/store/Coll.java
@@ -14,6 +14,7 @@ import java.util.concurrent.CopyOnWriteArrayList;
 import com.massivecraft.mcore4.MCore;
 import com.massivecraft.mcore4.MPlugin;
 import com.massivecraft.mcore4.Predictate;
+import com.massivecraft.mcore4.store.accessor.Accessor;
 import com.massivecraft.mcore4.store.idstrategy.IdStrategy;
 import com.massivecraft.mcore4.store.storeadapter.StoreAdapter;
 
@@ -121,9 +122,14 @@ public class Coll<E, L> implements CollInterface<E, L>
 	@Override public boolean isDefault(E entity) { return false; }
 	
 	// -------------------------------------------- //
-	// CREATE
+	// COPY AND CREATE
 	// -------------------------------------------- //
 	
+	public void copy(Object ofrom, Object oto)
+	{
+		Accessor.get(this.entityClass()).copy(ofrom, oto);
+	}
+	
 	// This simply creates and returns a new instance
 	// It does not detach/attach or anything. Just creates a new instance.
 	@Override
@@ -176,6 +182,7 @@ public class Coll<E, L> implements CollInterface<E, L>
 		return this.attach(entity, oid, true);
 	}
 
+	@SuppressWarnings({ "unchecked", "rawtypes" })
 	protected synchronized L attach(E entity, Object oid, boolean noteChange)
 	{
 		// Check entity
@@ -201,6 +208,12 @@ public class Coll<E, L> implements CollInterface<E, L>
 		this.id2entity.put(id, entity);
 		this.entity2id.put(entity, id);
 		
+		// Set this as the coll if possible.
+		if (entity instanceof Entity)
+		{
+			((Entity)entity).setColl(this);
+		}
+		
 		// Make note of the change
 		if (noteChange)
 		{
diff --git a/src/com/massivecraft/mcore4/store/CollInterface.java b/src/com/massivecraft/mcore4/store/CollInterface.java
index 24cc09fd..87e6fdbc 100644
--- a/src/com/massivecraft/mcore4/store/CollInterface.java
+++ b/src/com/massivecraft/mcore4/store/CollInterface.java
@@ -60,9 +60,11 @@ public interface CollInterface<E, L>
 	public boolean isDefault(E entity);
 	
 	// -------------------------------------------- //
-	// CREATE
+	// COPY AND CREATE
 	// -------------------------------------------- //
 	
+	public void copy(Object fromo, Object too);
+	
 	// This simply creates and returns a new instance
 	// It does not detach/attach or anything. Just creates a new instance.
 	public E createNewInstance();
diff --git a/src/com/massivecraft/mcore4/store/Colls.java b/src/com/massivecraft/mcore4/store/Colls.java
new file mode 100644
index 00000000..818264d7
--- /dev/null
+++ b/src/com/massivecraft/mcore4/store/Colls.java
@@ -0,0 +1,41 @@
+package com.massivecraft.mcore4.store;
+
+import java.util.HashMap;
+import java.util.Map;
+
+import com.massivecraft.mcore4.util.MUtil;
+
+public abstract class Colls<C extends Coll<E, L>, E, L>
+{
+	public abstract String name();
+	public abstract C createColl(String collName);
+	
+	public String collNameFromCategory(String category)
+	{
+		return this.name() + "_" + category;
+	}
+	
+	protected Map<String, C> name2coll = new HashMap<String, C>();
+	public C get(Object worldNameExtractable)
+	{
+		String worldName = MUtil.extract(String.class, "worldName", worldNameExtractable);
+		String category = WCatColl.i.get(this.name()).categorize(worldName);
+		String collName = this.collNameFromCategory(category);
+		
+		C ret = this.name2coll.get(collName);
+		if (ret == null)
+		{
+			ret = this.createColl(collName);
+			this.name2coll.put(collName, ret);
+		}
+		
+		return ret;
+	}
+	
+	public E get2(Object worldNameExtractable)
+	{
+		C coll = this.get(worldNameExtractable);
+		if (coll == null) return null;
+		return coll.get(worldNameExtractable);
+	}
+}
diff --git a/src/com/massivecraft/mcore4/store/Entity.java b/src/com/massivecraft/mcore4/store/Entity.java
index b1860833..4b910fb8 100644
--- a/src/com/massivecraft/mcore4/store/Entity.java
+++ b/src/com/massivecraft/mcore4/store/Entity.java
@@ -1,6 +1,8 @@
 package com.massivecraft.mcore4.store;
 
+import com.massivecraft.mcore4.MCore;
 import com.massivecraft.mcore4.store.accessor.Accessor;
+import com.massivecraft.mcore4.xlib.gson.Gson;
 
 /**
  * Usage of this class is highly optional. You may persist anything. If you are 
@@ -12,23 +14,34 @@ import com.massivecraft.mcore4.store.accessor.Accessor;
 // http://www.angelikalanger.com/GenericsFAQ/FAQSections/ProgrammingIdioms.html#FAQ206
 public abstract class Entity<E extends Entity<E, L>, L>
 {
-	public abstract Coll<E, L> getColl();
+	protected transient Coll<E, L> coll;
+	protected void setColl(Coll<E, L> val) { this.coll = val; }
+	public Coll<E, L> getColl() { return this.coll; }
 	
 	protected abstract E getThis();
+	protected abstract Class<E> getClazz();
 	
-	public L attach()
+	public abstract E getDefaultInstance();
+	
+	public L attach(Coll<E, L> coll)
 	{
-		return this.getColl().attach(getThis());
+		return coll.attach(getThis());
 	}
 	
 	public E detach()
 	{
-		return this.getColl().detach(getThis());
+		Coll<E, L> coll = this.getColl();
+		if (coll == null) return null;
+		
+		return coll.detach(getThis());
 	}
 	
 	public boolean attached()
 	{
-		return this.getColl().getAll().contains(getThis());
+		Coll<E, L> coll = this.getColl();
+		if (coll == null) return false;
+		
+		return coll.getAll().contains(getThis());
 	}
 	
 	public boolean detached()
@@ -38,15 +51,16 @@ public abstract class Entity<E extends Entity<E, L>, L>
 	
 	public L getId()
 	{
-		return this.getColl().id(getThis());
+		Coll<E, L> coll = this.getColl();
+		if (coll == null) return null;
+		return coll.id(this.getThis());
 	}
 	
-	// TODO: Perhaps even brute force methods to save or load from remote.
-	
 	public void changed()
 	{
 		L id = this.getId();
 		if (id == null) return;
+		
 		this.getColl().changedIds.add(id);
 	}
 	
@@ -54,6 +68,7 @@ public abstract class Entity<E extends Entity<E, L>, L>
 	{
 		L id = this.getId();
 		if (id == null) return;
+		
 		this.getColl().syncId(id);
 	}
 	
@@ -61,6 +76,7 @@ public abstract class Entity<E extends Entity<E, L>, L>
 	{
 		L id = this.getId();
 		if (id == null) return;
+		
 		this.getColl().saveToRemote(id);
 	}
 	
@@ -68,29 +84,29 @@ public abstract class Entity<E extends Entity<E, L>, L>
 	{
 		L id = this.getId();
 		if (id == null) return;
+		
 		this.getColl().loadFromRemote(id);
 	}
 	
 	@Override
 	public String toString()
 	{
-		return this.getClass().getSimpleName()+this.getColl().mplugin().gson.toJson(this, this.getColl().entityClass());
-	}
-	
-	public E getDefaultInstance()
-	{
-		return this.getColl().createNewInstance();
+		Gson gson = MCore.gson;
+		Coll<E, L> coll = this.getColl();
+		if (coll != null) gson = coll.mplugin().gson;
+		
+		return this.getClazz().getSimpleName()+gson.toJson(this, this.getClazz());
 	}
 	
 	public E loadDefaults()
 	{
-		Accessor.get(this.getColl().entityClass()).copy(this.getDefaultInstance(), this.getThis());
+		Accessor.get(this.getClazz()).copy(this.getDefaultInstance(), this.getThis());
 		return this.getThis();
 	}
 	
 	public E load(E entity)
 	{
-		Accessor.get(this.getColl().entityClass()).copy(entity, this.getThis());
+		Accessor.get(this.getClazz()).copy(entity, this.getThis());
 		return this.getThis();
 	}
 }
diff --git a/src/com/massivecraft/mcore4/store/WCat.java b/src/com/massivecraft/mcore4/store/WCat.java
new file mode 100644
index 00000000..8197ce22
--- /dev/null
+++ b/src/com/massivecraft/mcore4/store/WCat.java
@@ -0,0 +1,92 @@
+package com.massivecraft.mcore4.store;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Iterator;
+import java.util.List;
+
+import com.massivecraft.mcore4.util.MUtil;
+
+/**
+ * WCat stands for World Categorizer.
+ * They provide a recursive matching system.
+ */
+public class WCat extends Entity<WCat, String>
+{
+	public final static transient String RETURN = "_return";
+	public final static transient String RUN = "_run";
+	public final static transient String _DEFAULT = "_default";
+	public final static transient String DEFAULT = "default";
+	public final static transient List<WCatRule> DEFAULT_RULES = MUtil.list(new WCatRule(RUN, _DEFAULT));
+	public final static transient List<WCatRule> DEFAULT_DEFAULT_RULES = MUtil.list(new WCatRule(RETURN, DEFAULT));
+	
+	// -------------------------------------------- //
+	// META
+	// -------------------------------------------- //
+	
+	@Override public Coll<WCat, String> getColl() { return WCatColl.i; }
+	@Override protected WCat getThis() { return this; }
+	
+	private final static transient WCat defaultInstance = new WCat();
+	@Override public WCat getDefaultInstance(){ return defaultInstance; }
+	@Override protected Class<WCat> getClazz() { return WCat.class; }
+	
+	
+	// -------------------------------------------- //
+	// FIELDS
+	// -------------------------------------------- //
+	
+	protected List<WCatRule> rules;
+	public List<WCatRule> rules() { return this.rules; };
+	public void rules(List<WCatRule> val) { this.rules = new ArrayList<WCatRule>(val); };
+	public void rules(String... namesAndParams)
+	{
+		this.rules = new ArrayList<WCatRule>();
+		Iterator<String> iter = Arrays.asList(namesAndParams).iterator();
+		while (iter.hasNext())
+		{
+			String name = iter.next();
+			String param = iter.next();
+			this.rules.add(new WCatRule(name, param));
+		}
+	}
+	
+	// -------------------------------------------- //
+	// CONSTRUCT
+	// -------------------------------------------- //
+	
+	public WCat()
+	{
+		this.rules(DEFAULT_RULES);
+	}
+	
+	// -------------------------------------------- //
+	// THAT SPECIAL LOGIC
+	// -------------------------------------------- //
+	
+	public String categorize(String worldName)
+	{
+		for (WCatRule rule : this.rules())
+		{
+			String name = rule.name();
+			String param = rule.param();
+			if (name.equals(RETURN))
+			{
+				return param;
+			}
+			else if (name.equals(RUN))
+			{
+				WCat subcat = WCatColl.i.get(param);
+				String subcatresult = subcat.categorize(worldName);
+				if (subcatresult != null) return subcatresult;
+			}
+			else if (name.equalsIgnoreCase(worldName))
+			{
+				return param;
+			}
+		}
+		return null;
+	}
+	
+	
+}
diff --git a/src/com/massivecraft/mcore4/store/WCatColl.java b/src/com/massivecraft/mcore4/store/WCatColl.java
new file mode 100644
index 00000000..aa42a542
--- /dev/null
+++ b/src/com/massivecraft/mcore4/store/WCatColl.java
@@ -0,0 +1,41 @@
+package com.massivecraft.mcore4.store;
+
+import com.massivecraft.mcore4.MCore;
+
+public class WCatColl extends Coll<WCat, String>
+{
+	// -------------------------------------------- //
+	// META
+	// -------------------------------------------- //
+	public static WCatColl i = new WCatColl();
+	
+	private WCatColl()
+	{
+		super(MCore.p, "ai", "mcore_wcat", WCat.class, String.class, true);
+	}
+	
+	@Override
+	public void copy(Object ofrom, Object oto)
+	{
+		WCat from = (WCat)ofrom;
+		WCat to = (WCat)oto;
+		to.rules = from.rules;
+	}
+	
+	@Override
+	public void init()
+	{
+		super.init();
+		
+		// Ensure the default WorldCategorizer is present.
+		WCat d = this.get(WCat._DEFAULT);
+		d.rules(WCat.DEFAULT_DEFAULT_RULES);
+	}
+	
+	@Override
+	public boolean isDefault(WCat entity)
+	{
+		return entity.rules().equals(WCat.DEFAULT_RULES);
+	}
+	
+}
diff --git a/src/com/massivecraft/mcore4/store/WCatRule.java b/src/com/massivecraft/mcore4/store/WCatRule.java
new file mode 100644
index 00000000..e82da987
--- /dev/null
+++ b/src/com/massivecraft/mcore4/store/WCatRule.java
@@ -0,0 +1,22 @@
+package com.massivecraft.mcore4.store;
+
+public class WCatRule
+{
+	protected final String name;
+	public String name() { return this.name; }
+	
+	protected final String param;
+	public String param() { return this.param; }
+	
+	public WCatRule()
+	{
+		this.name = null;
+		this.param = null;
+	}
+	
+	public WCatRule(String name, String param)
+	{
+		this.name = name;
+		this.param = param;
+	}
+}
diff --git a/src/com/massivecraft/mcore4/store/storeadapter/StoreAdapterGson.java b/src/com/massivecraft/mcore4/store/storeadapter/StoreAdapterGson.java
index 95170d37..7c7bff70 100644
--- a/src/com/massivecraft/mcore4/store/storeadapter/StoreAdapterGson.java
+++ b/src/com/massivecraft/mcore4/store/storeadapter/StoreAdapterGson.java
@@ -1,7 +1,6 @@
 package com.massivecraft.mcore4.store.storeadapter;
 
 import com.massivecraft.mcore4.store.Coll;
-import com.massivecraft.mcore4.store.accessor.Accessor;
 import com.massivecraft.mcore4.xlib.gson.JsonElement;
 
 public class StoreAdapterGson extends StoreAdapterAbstract
@@ -21,7 +20,7 @@ public class StoreAdapterGson extends StoreAdapterAbstract
 	public void write(Coll<?, ?> coll, Object raw, Object entity)
 	{
 		Object temp = coll.mplugin().gson.fromJson((JsonElement)raw, coll.entityClass());
-		Accessor.get(coll.entityClass()).copy(temp, entity);
+		coll.copy(temp, entity);
 	}
 	
 	// -------------------------------------------- //
diff --git a/src/com/massivecraft/mcore4/util/MUtil.java b/src/com/massivecraft/mcore4/util/MUtil.java
index 59f8e668..ceed877f 100644
--- a/src/com/massivecraft/mcore4/util/MUtil.java
+++ b/src/com/massivecraft/mcore4/util/MUtil.java
@@ -3,6 +3,7 @@ package com.massivecraft.mcore4.util;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Comparator;
+import java.util.HashMap;
 import java.util.HashSet;
 import java.util.Iterator;
 import java.util.LinkedHashMap;
@@ -23,6 +24,8 @@ import org.bukkit.event.entity.EntityDamageEvent.DamageCause;
 import org.bukkit.event.player.PlayerInteractEvent;
 
 import com.massivecraft.mcore4.MCore;
+import com.massivecraft.mcore4.util.extractor.Extractor;
+import com.massivecraft.mcore4.util.extractor.ExtractorWorldName;
 
 public class MUtil
 {
@@ -171,4 +174,58 @@ public class MUtil
 		if (MCore.random.nextDouble() < prob) ret += 1;
 		return ret;
 	}
+	
+	// -------------------------------------------- //
+	// EXTRACTION
+	// -------------------------------------------- //
+	
+	protected static Map<Class<?>, Map<String, Set<Extractor>>> classesPropertiesExtractors = new HashMap<Class<?>, Map<String, Set<Extractor>>>();
+	protected static Map<String, Set<Extractor>> getPropertiesExtractors(Class<?> propertyClass)
+	{
+		Map<String, Set<Extractor>> ret = classesPropertiesExtractors.get(propertyClass);
+		if (ret == null)
+		{
+			ret = new HashMap<String, Set<Extractor>>();
+			classesPropertiesExtractors.put(propertyClass, ret);
+		}
+		return ret;
+	}
+	
+	protected static Set<Extractor> getExtractors(Class<?> propertyClass, String propertyName)
+	{
+		Map<String, Set<Extractor>> propertiesExtractors = getPropertiesExtractors(propertyClass);
+		Set<Extractor> ret = propertiesExtractors.get(propertyName);
+		if (ret == null)
+		{
+			ret = new HashSet<Extractor>();
+			propertiesExtractors.put(propertyName, ret);
+		}
+		return ret;
+	}
+	
+	@SuppressWarnings("unchecked")
+	public static <T> T extract(Class<T> propertyClass, String propertyName, Object o)
+	{
+		Object ret = null;
+		for (Extractor extractor : getExtractors(propertyClass, propertyName))
+		{
+			ret = extractor.extract(o);
+			if (ret != null) break;
+		}
+		return (T) ret;
+	}
+	
+	public static <T> void registerExtractor(Class<T> clazz, String propertyName, Extractor extractor)
+	{
+		getExtractors(clazz, propertyName).add(extractor);
+	}
+	
+	// -------------------------------------------- //
+	// STATIC CONSTRUCT
+	// -------------------------------------------- //
+	
+	static
+	{
+		registerExtractor(String.class, "worldName", new ExtractorWorldName());
+	}
 }
diff --git a/src/com/massivecraft/mcore4/util/Txt.java b/src/com/massivecraft/mcore4/util/Txt.java
index 2700dc26..edd13c54 100644
--- a/src/com/massivecraft/mcore4/util/Txt.java
+++ b/src/com/massivecraft/mcore4/util/Txt.java
@@ -226,7 +226,7 @@ public class Txt
 	        }
 	        else
 	        {
-	        	ret.append(list[i].toString());
+	        	ret.append(str);
 	        }
 	    }
 	    return ret.toString();
diff --git a/src/com/massivecraft/mcore4/util/extractor/Extractor.java b/src/com/massivecraft/mcore4/util/extractor/Extractor.java
new file mode 100644
index 00000000..cf43d67a
--- /dev/null
+++ b/src/com/massivecraft/mcore4/util/extractor/Extractor.java
@@ -0,0 +1,6 @@
+package com.massivecraft.mcore4.util.extractor;
+
+public interface Extractor
+{
+	public Object extract(Object o);
+}
diff --git a/src/com/massivecraft/mcore4/util/extractor/ExtractorWorldName.java b/src/com/massivecraft/mcore4/util/extractor/ExtractorWorldName.java
new file mode 100644
index 00000000..bd599519
--- /dev/null
+++ b/src/com/massivecraft/mcore4/util/extractor/ExtractorWorldName.java
@@ -0,0 +1,22 @@
+package com.massivecraft.mcore4.util.extractor;
+
+import org.bukkit.Location;
+import org.bukkit.World;
+import org.bukkit.block.Block;
+import org.bukkit.entity.Entity;
+import org.bukkit.event.player.PlayerEvent;
+
+public class ExtractorWorldName implements Extractor
+{
+	@Override
+	public Object extract(Object o)
+	{
+		if (o instanceof String) return o;
+		if (o instanceof World) return ((World)o).getName();
+		if (o instanceof Block) return ((Block)o).getWorld().getName();
+		if (o instanceof Location) return ((Location)o).getWorld().getName();
+		if (o instanceof Entity) return ((Entity)o).getWorld().getName();
+		if (o instanceof PlayerEvent) return ((PlayerEvent)o).getPlayer().getWorld().getName();
+		return null;
+	}
+}