diff --git a/src/main/puml/GameWorld.puml b/src/main/puml/GameWorld.puml
new file mode 100644
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+++ b/src/main/puml/GameWorld.puml
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+@startuml
+
+note as N1
+    This UML Class Diagram introduces the
+    GameWorlds and GameModes concepts that
+    are introduced in 1.0.
+
+    This diagram is not meant to be updated
+    alongside modifications that could be done
+    to GameWorlds and GameModes: it is meant
+    to serve as a template, and hopefully to keep
+    track of what we had in mind when we started
+    to work on this API.
+
+    - Poslovitch, @BentoBoxWorld
+    December 24th, 2018.
+end note
+
+package world.bentobox.bentobox {
+
+    class BentoBox << (M,orchid) Main >> {
+        - addonsManager : AddonsManager
+        - worldsManager : WorldsManager
+        + getAddons() : AddonsManager
+        + getWorlds() : WorldsManager
+    }
+
+    package api {
+        package addons {
+            abstract class Addon
+
+            abstract class GameMode extends Addon {
+                Specific Addon implementation allowing to register GameWorlds.
+
+                + registerGameWorld(gameWorld:GameWorld) : void
+                + getGameWorlds() : List<GameWorld>
+            }
+        }
+
+        package worlds {
+            interface WorldSettings
+
+            class GameWorld {
+                Represents a set of three Worlds
+                (Overworld, Nether, End) which is
+                registered by a GameMode addon and
+                managed by BentoBox.
+                It features its own implementation
+                of WorldSettings and provides
+                Islands and Schems managers.
+                __ Fields __
+                - name : String
+                - friendlyName : String
+                - overWorld : World
+                - netherWorld : World
+                - endWorld : World
+                - worldSettings : WorldSettings
+                .. Managers ..
+                - islandsManager : IslandsManager
+                - schemsManager : SchemsManager
+                __ Methods __
+                + createWorlds() : boolean
+                + inWorld(location:Location) : boolean
+                .. Getters ..
+                + getName() : String
+                + getFriendlyName() : String
+                + getOverWorld() : World
+                + getNetherWorld() : World
+                + getEndWorld() : World
+                + getSettings() : WorldSettings
+                + getIslands() : IslandsManager
+                + getSchems() : SchemsManager
+                }
+
+            GameWorld *-- "1" WorldSettings
+
+            GameMode *-- "*" GameWorld
+        }
+    }
+
+
+    package managers {
+        class AddonsManager
+
+        BentoBox *-- "1" AddonsManager
+        AddonsManager *-- "*" Addon
+
+        class WorldsManager {
+            Manages GameWorlds that are registered by GameMode addons.
+            It basically replaces IslandWorldManager.
+            __ Fields __
+            - gameWorlds : Map<GameMode, List<GameWorld>>
+            __ Methods __
+            + registerGameWorld(gameMode:GameMode, gameWorld:GameWorld) : boolean
+            .. Getters ..
+            + getGameWorldsMap() : Map<GameMode, List<GameWorld>>
+            + getGameWorldsList() : List<GameWorld>
+            + getGameWorlds(gameMode:GameMode) : List<GameWorld>
+            + getGameWorld(name:String) : Optional<GameWorld>
+            + getGameWorld(world:World) : Optional<GameWorld>
+            .. Multiverse ..
+            + registerWorldsToMultiverse() : void
+            + registerWorldToMultiverse(gameWorld:GameWorld) : void
+        }
+
+        BentoBox *-- "1" WorldsManager
+        WorldsManager *-- "*" GameWorld
+
+        class SchemsManager {
+            - schems : List<Clipboard>
+
+            - copySchems(schems:File, name:String) : void
+            - loadSchem(name:String) : boolean
+            + getSchems() : List<Clipboard>
+            + paste(island:Island, task:Runnable) : void
+            + paste(island:Island) : void
+        }
+
+        GameWorld *-- "1" SchemsManager
+    }
+}
+
+@enduml