diff --git a/Nu/Nu/Nu/DesyncTests.fs b/Nu/Nu/Nu/DesyncTests.fs
index c9e74893d6..3d8528d94e 100644
--- a/Nu/Nu/Nu/DesyncTests.fs
+++ b/Nu/Nu/Nu/DesyncTests.fs
@@ -19,8 +19,7 @@ module DesyncTests =
     let [<Fact>] desyncWorks () =
         
         // build everything
-        World.init ()
-        let world = World.makeEmpty 0
+        let world = World.initAndMakeEmpty 0
         let desync =
             desync {
                 let! e = next
diff --git a/Nu/Nu/Nu/Entity.fs b/Nu/Nu/Nu/Entity.fs
index 5a1870eb47..f335f03dae 100644
--- a/Nu/Nu/Nu/Entity.fs
+++ b/Nu/Nu/Nu/Entity.fs
@@ -366,7 +366,7 @@ module WorldEntityModule =
         /// Remove an entity from the world immediately. Can be dangerous if existing in-flight
         /// subscriptions depend on the entity's existence. Use with caution.
         static member removeEntityImmediate (address : Entity Address) world =
-            let world = World.publish4 () (RemovingEventAddress ->>- address) address world
+            let world = World.publish4 () (EntityRemovingEventAddress ->>- address) address world
             match World.getOptEntity address world with
             | Some entity ->
                 let (entity, world) = World.unregisterEntity entity address world
@@ -402,7 +402,7 @@ module WorldEntityModule =
             if not <| World.containsEntity address world then
                 let world = World.setEntityWithoutEvent entity address world
                 let (entity, world) = World.registerEntity entity address world
-                let world = World.publish4 () (AddEventAddress ->>- address) address world
+                let world = World.publish4 () (EntityAddEventAddress ->>- address) address world
                 (entity, world)
             else failwith <| "Adding an entity that the world already contains at address '" + acstring address + "'."
 
diff --git a/Nu/Nu/Nu/Group.fs b/Nu/Nu/Nu/Group.fs
index a97d319107..8b623be45e 100644
--- a/Nu/Nu/Nu/Group.fs
+++ b/Nu/Nu/Nu/Group.fs
@@ -261,7 +261,7 @@ module WorldGroupModule =
         /// Remove a group from the world immediately. Can be dangerous if existing in-flight
         /// subscriptions depend on the group's existence. Use with caution.
         static member removeGroupImmediate address world =
-            let world = World.publish4 () (RemovingEventAddress ->>- address) address world
+            let world = World.publish4 () (GroupRemovingEventAddress ->>- address) address world
             match World.getOptGroup address world with
             | Some group ->
                 let (group, world) = World.unregisterGroup group address world
@@ -301,7 +301,7 @@ module WorldGroupModule =
                 let world = World.setGroupWithoutEvent group address world
                 let world = snd <| World.addEntities entities address world
                 let (group, world) = World.registerGroup group address world
-                let world = World.publish4 () (AddEventAddress ->>- address) address world
+                let world = World.publish4 () (GroupAddEventAddress ->>- address) address world
                 (group, world)
             else failwith <| "Adding a group that the world already contains at address '" + acstring address + "'."
 
diff --git a/Nu/Nu/Nu/Observation.fs b/Nu/Nu/Nu/Observation.fs
index 62c2b83721..db564f4547 100644
--- a/Nu/Nu/Nu/Observation.fs
+++ b/Nu/Nu/Nu/Observation.fs
@@ -249,7 +249,8 @@ module Observation =
 
     /// Terminate an observation when the observer is removed from the world.
     let lifetime (observation : Observation<'a, 'o>) : Observation<'a, 'o> =
-        until (RemovingEventAddress ->>- observation.ObserverAddress) observation
+        let removingEventAddress = stoa<unit> (typeof<'o>.Name + "/" + "Removing") ->>- observation.ObserverAddress
+        until removingEventAddress observation
 
     /// Subscribe to an observation until the observer is removed from the world,
     /// returning both an unsubscription procedure as well as the world as augmented with said
@@ -428,7 +429,8 @@ module Observation =
 
     /// Make an observation from an observer address and the observer's change events.
     let observeSimulantValue (valueGetter : 'a -> 'b) (simulantAddress : 'a Address) (observerAddress : 'o Address) =
-        let changeEventAddress = Address.changeType<Simulant SimulantChangeData, 'a SimulantChangeData> SimulantChangeEventAddress ->>- simulantAddress
+        let simulantChangeEventAddress = stoa<'a SimulantChangeData> (typeof<'a>.Name + "/Change")
+        let changeEventAddress = simulantChangeEventAddress ->>- simulantAddress
         observe changeEventAddress observerAddress |>
         simulantValue valueGetter
 
diff --git a/Nu/Nu/Nu/ObservationTests.fs b/Nu/Nu/Nu/ObservationTests.fs
index 64c59e65bf..3c6c5f9a1f 100644
--- a/Nu/Nu/Nu/ObservationTests.fs
+++ b/Nu/Nu/Nu/ObservationTests.fs
@@ -18,15 +18,13 @@ module ObservationTests =
     let incUserStateAndResolve _ world = (Resolve, World.updateUserState inc world)
 
     let [<Fact>] subscribeWorks () =
-        World.init ()
-        let world = World.makeEmpty 0
+        let world = World.initAndMakeEmpty 0
         let world = observe UnitEventAddress GameAddress |> subscribe incUserStateAndCascade <| world
         let world = World.publish4 () UnitEventAddress GameAddress world
         Assert.Equal (1, World.getUserState world)
 
     let [<Fact>] subscribeTwiceUnsubscribeOnceWorks () =
-        World.init ()
-        let world = World.makeEmpty 0
+        let world = World.initAndMakeEmpty 0
         let observation = observe UnitEventAddress GameAddress
         let world = subscribe incUserStateAndCascade observation world
         let (unsubscribe, world) = subscribeWithUnsub incUserStateAndCascade observation world
@@ -35,8 +33,7 @@ module ObservationTests =
         Assert.Equal (1, World.getUserState world)
 
     let [<Fact>] unsubscribeWorks () =
-        World.init ()
-        let world = World.makeEmpty 0
+        let world = World.initAndMakeEmpty 0
         let (unsubscribe, world) = observe UnitEventAddress GameAddress |> subscribeWithUnsub incUserStateAndCascade <| world
         let world = unsubscribe world
         let world = World.publish4 () UnitEventAddress GameAddress world
@@ -44,8 +41,7 @@ module ObservationTests =
         Assert.Equal (0, World.getUserState world)
 
     let [<Fact>] filterWorks () =
-        World.init ()
-        let world = World.makeEmpty 0
+        let world = World.initAndMakeEmpty 0
         let world =
             observe UnitEventAddress GameAddress |>
             filter (fun _ world -> World.getUserState world = 0) |>
@@ -56,8 +52,7 @@ module ObservationTests =
         Assert.Equal (1, World.getUserState world)
 
     let [<Fact>] mapWorks () =
-        World.init ()
-        let world = World.makeEmpty 0
+        let world = World.initAndMakeEmpty 0
         let world =
             observe IntEventAddress GameAddress |>
             map (fun event _ -> event.Data * 2) |>
@@ -67,8 +62,7 @@ module ObservationTests =
         Assert.Equal (2, World.getUserState world)
 
     let [<Fact>] scanWorks () =
-        World.init ()
-        let world = World.makeEmpty 0
+        let world = World.initAndMakeEmpty 0
         let world =
             observe IntEventAddress GameAddress |>
             scan (fun acc event _ -> acc + event.Data) 0 |>
@@ -79,8 +73,7 @@ module ObservationTests =
         Assert.Equal (3, World.getUserState world)
 
     let [<Fact>] scanDoesntLeaveGarbage () =
-        World.init ()
-        let world = World.makeEmpty 0
+        let world = World.initAndMakeEmpty 0
         let (unsubscribe, world) =
             observe IntEventAddress GameAddress |>
             scan2 (fun a _ _ -> a) |>
@@ -91,8 +84,7 @@ module ObservationTests =
         Assert.True <| Map.isEmpty world.Callbacks.CallbackStates
 
     let [<Fact>] discreteFrpWorks () =
-        World.init ()
-        let world = World.makeEmpty 0
+        let world = World.initAndMakeEmpty 0
         let jim = World.makeEntity typeof<EntityDispatcher>.Name (Some JimName) world
         let bob = World.makeEntity typeof<EntityDispatcher>.Name (Some BobName) world
         let group = World.makeGroup typeof<GroupDispatcher>.Name (Some DefaultGroupName) world
@@ -104,8 +96,7 @@ module ObservationTests =
         Assert.True <| World.getEntityBy (not << Entity.getVisible) JimAddress world
 
     let [<Fact>] discreteFrpCyclicWorks () =
-        World.init ()
-        let world = World.makeEmpty 0
+        let world = World.initAndMakeEmpty 0
         let jim = World.makeEntity typeof<EntityDispatcher>.Name (Some JimName) world
         let bob = World.makeEntity typeof<EntityDispatcher>.Name (Some BobName) world
         let group = World.makeGroup typeof<GroupDispatcher>.Name (Some DefaultGroupName) world
diff --git a/Nu/Nu/Nu/Screen.fs b/Nu/Nu/Nu/Screen.fs
index c183e5eda9..044468c6c5 100644
--- a/Nu/Nu/Nu/Screen.fs
+++ b/Nu/Nu/Nu/Screen.fs
@@ -249,7 +249,7 @@ module WorldScreenModule =
         /// Remove a screen from the world immediately. Can be dangerous if existing in-flight
         /// subscriptions depend on the screen's existence. Use with caution.
         static member removeScreenImmediate address world =
-            let world = World.publish4 () (RemovingEventAddress ->>- address) address world
+            let world = World.publish4 () (ScreenRemovingEventAddress ->>- address) address world
             match World.getOptScreen address world with
             | Some screen ->
                 let (screen, world) = World.unregisterScreen screen address world
@@ -274,7 +274,7 @@ module WorldScreenModule =
                 let world = World.setScreenWithoutEvent screen address world
                 let world = snd <| World.addGroups groupHierarchies address world
                 let (screen, world) = World.registerScreen screen address world
-                let world = World.publish4 () (AddEventAddress ->>- address) address world
+                let world = World.publish4 () (ScreenAddEventAddress ->>- address) address world
                 (screen, world)
             else failwith <| "Adding a screen that the world already contains at address '" + acstring address + "'."
 
diff --git a/Nu/Nu/Nu/World.fs b/Nu/Nu/Nu/World.fs
index 4cb68c13c7..506c6b2a83 100644
--- a/Nu/Nu/Nu/World.fs
+++ b/Nu/Nu/Nu/World.fs
@@ -528,7 +528,7 @@ module WorldModule =
             let tasksNotRun = List.rev tasksNotRun
             World.restoreTasks tasksNotRun world
 
-        /// Process an input event from SDL and ultimately publish any related Nu engine events.
+        /// Process an input event from SDL and ultimately publish any related game events.
         static member processInput (event : SDL.SDL_Event) world =
             let world =
                 match event.``type`` with
@@ -575,7 +575,7 @@ module WorldModule =
             (world.State.Liveness, world)
 
         /// Update the Nu game engine once per frame, updating its subsystems and publishing the
-        /// global tick event.
+        /// game tick event.
         static member processUpdate handleUpdate world =
             let world = handleUpdate world
             match world.State.Liveness with
@@ -844,4 +844,15 @@ module WorldModule =
             Math.initTypeConverters ()
 
             // assign this crazy function
-            World.getOptSimulantForPublishing <- World.getOptSimulantForPublishingDefinition
\ No newline at end of file
+            World.getOptSimulantForPublishing <- World.getOptSimulantForPublishingDefinition
+
+        /// Initialize the Nu game engine, and make an empty world. Useful for unit-testing.
+        static member initAndMakeEmpty (userState : 'u) =
+            World.init ()
+            World.makeEmpty userState
+
+        /// Initialize the Nu game engine and try to make the world, returning either a Right
+        //// World on success, or a Left string (with an error message) on failure.
+        static member initAndTryMake farseerCautionMode useLoadedGameDispatcher interactivity userState nuPlugin sdlDeps =
+            World.init ()
+            World.tryMake farseerCautionMode useLoadedGameDispatcher interactivity userState nuPlugin sdlDeps
\ No newline at end of file
diff --git a/Nu/Nu/Nu/WorldConstants.fs b/Nu/Nu/Nu/WorldConstants.fs
index c86523fd89..26ec4fdb4b 100644
--- a/Nu/Nu/Nu/WorldConstants.fs
+++ b/Nu/Nu/Nu/WorldConstants.fs
@@ -12,8 +12,6 @@ module WorldConstants =
     let DefaultEntityAddress = gatoea DefaultGroupAddress DefaultEntityName
     let AnyEventAddress = ntoa<obj> "*"
     let TickEventAddress = ntoa<unit> "Tick"
-    let AddEventAddress = ntoa<unit> "Add"
-    let RemovingEventAddress = ntoa<unit> "Removing"
     let SelectEventAddress = ntoa<unit> "Select"
     let DeselectEventAddress = ntoa<unit> "Deselect"
     let DownEventAddress = ntoa<unit> "Down"
@@ -57,12 +55,20 @@ module WorldConstants =
     let OutgoingEventAddress = ntoa<unit> "Outgoing"
     let OutgoingStartEventAddress = OutgoingEventAddress -|- ntoa "Start"
     let OutgoingFinishEventAddress = OutgoingEventAddress -|- ntoa "Finish"
-    let WorldStateEventAddress = ntoa<WorldStateChangeData> "WorldState"
-    let WorldStateChangeEventAddress = WorldStateEventAddress -|- ntoa "Change"
-    let SimulantEventAddress = ntoa<Simulant SimulantChangeData> "Simulant"
-    let SimulantChangeEventAddress = SimulantEventAddress -|- ntoa "Change"
-    let GameChangeEventAddress = Address.changeType<Simulant SimulantChangeData, Game SimulantChangeData> SimulantChangeEventAddress
-    let ScreenChangeEventAddress = Address.changeType<Simulant SimulantChangeData, Screen SimulantChangeData> SimulantChangeEventAddress
-    let GroupChangeEventAddress = Address.changeType<Simulant SimulantChangeData, Group SimulantChangeData> SimulantChangeEventAddress
-    let EntityChangeEventAddress = Address.changeType<Simulant SimulantChangeData, Entity SimulantChangeData> SimulantChangeEventAddress
+    let WorldStateEventAddress = ntoa<obj> "WorldState"
+    let WorldStateChangeEventAddress = WorldStateEventAddress -<- ntoa<WorldStateChangeData> "Change"
+    let GameEventAddress = ntoa<obj> "Game"
+    let GameChangeEventAddress = GameEventAddress -<- ntoa<Game SimulantChangeData> "Change"
+    let ScreenEventAddress = ntoa<obj> "Screen"
+    let ScreenAddEventAddress = ScreenEventAddress -<- ntoa<unit> "Add"
+    let ScreenRemovingEventAddress = ScreenEventAddress -<- ntoa<unit> "Removing"
+    let ScreenChangeEventAddress = ScreenEventAddress -<- ntoa<Screen SimulantChangeData> "Change"
+    let GroupEventAddress = ntoa<obj> "Group"
+    let GroupAddEventAddress = GroupEventAddress -<- ntoa<unit> "Add"
+    let GroupRemovingEventAddress = GroupEventAddress -<- ntoa<unit> "Removing"
+    let GroupChangeEventAddress = GroupEventAddress -<- ntoa<Group SimulantChangeData> "Change"
+    let EntityEventAddress = ntoa<obj> "Entity"
+    let EntityAddEventAddress = EntityEventAddress -<- ntoa<unit> "Add"
+    let EntityRemovingEventAddress = EntityEventAddress -<- ntoa<unit> "Removing"
+    let EntityChangeEventAddress = EntityEventAddress -<- ntoa<Entity SimulantChangeData> "Change"
     let DefaultDissolveImage = { PackageName = DefaultPackageName; AssetName = "Image8" }
\ No newline at end of file
diff --git a/Nu/Nu/Nu/WorldPrimitives.fs b/Nu/Nu/Nu/WorldPrimitives.fs
index 951c5ebaf7..3bb1b56342 100644
--- a/Nu/Nu/Nu/WorldPrimitives.fs
+++ b/Nu/Nu/Nu/WorldPrimitives.fs
@@ -325,7 +325,7 @@ module World =
                 let world = unsubscribe removalKey world
                 let world = unsubscribe monitorKey world
                 (Cascade, world)
-            let removingEventAddress = RemovingEventAddress ->- atooa subscriberAddress
+            let removingEventAddress = stoa<unit> (typeof<'s>.Name + "/" + "Removing") ->>- subscriberAddress
             subscribe<unit, 's> removalKey subscription' removingEventAddress subscriberAddress world
         else failwith "Cannot monitor events with an anonymous subscriber."
 
diff --git a/Nu/Nu/Nu/WorldTests.fs b/Nu/Nu/Nu/WorldTests.fs
index fd8615829d..803cb9d082 100644
--- a/Nu/Nu/Nu/WorldTests.fs
+++ b/Nu/Nu/Nu/WorldTests.fs
@@ -17,8 +17,7 @@ module WorldTests =
     let incUserStateAndResolve (_ : Event<unit, Game>) world = (Resolve, World.updateUserState inc world)
 
     let [<Fact>] emptyWorldDoesntExplode () =
-        World.init ()
-        let world = World.makeEmpty ()
+        let world = World.initAndMakeEmpty ()
         match World.processInput (SDL.SDL_Event ()) world with
         | (Running, world) ->
             match World.processUpdate id world with
@@ -29,48 +28,42 @@ module WorldTests =
         | (Exiting, _) -> failwith "Test should not reach here."
 
     let [<Fact>] subscribeWorks () =
-        World.init ()
-        let world = World.makeEmpty 0
+        let world = World.initAndMakeEmpty 0
         let world = World.subscribe4 incUserStateAndCascade UnitEventAddress GameAddress world
         let world = World.publish4 () UnitEventAddress GameAddress world
         Assert.Equal (1, World.getUserState world)
 
     let [<Fact>] subscribeAndPublishTwiceWorks () =
-        World.init ()
-        let world = World.makeEmpty 0
+        let world = World.initAndMakeEmpty 0
         let world = World.subscribe4 incUserStateAndCascade UnitEventAddress GameAddress world
         let world = World.publish4 () UnitEventAddress GameAddress world
         let world = World.publish4 () UnitEventAddress GameAddress world
         Assert.Equal (2, World.getUserState world)
 
     let [<Fact>] subscribeTwiceAndPublishWorks () =
-        World.init ()
-        let world = World.makeEmpty 0
+        let world = World.initAndMakeEmpty 0
         let world = World.subscribe4 incUserStateAndCascade UnitEventAddress GameAddress world
         let world = World.subscribe4 incUserStateAndCascade UnitEventAddress GameAddress world
         let world = World.publish4 () UnitEventAddress GameAddress world
         Assert.Equal (2, World.getUserState world)
 
     let [<Fact>] subscribeWithResolutionWorks () =
-        World.init ()
-        let world = World.makeEmpty 0
+        let world = World.initAndMakeEmpty 0
         let world = World.subscribe4 incUserStateAndCascade UnitEventAddress GameAddress world
         let world = World.subscribe4 incUserStateAndResolve UnitEventAddress GameAddress world
         let world = World.publish4 () UnitEventAddress GameAddress world
         Assert.Equal (1, World.getUserState world)
 
     let [<Fact>] unsubscribeWorks () =
-        World.init ()
+        let world = World.initAndMakeEmpty 0
         let key = World.makeSubscriptionKey ()
-        let world = World.makeEmpty 0
         let world = World.subscribe key incUserStateAndResolve UnitEventAddress GameAddress world
         let world = World.unsubscribe key world
         let world = World.publish4 () UnitEventAddress GameAddress world
         Assert.Equal (0, World.getUserState world)
 
     let [<Fact>] entitySubscribeWorks () =
-        World.init ()
-        let world = World.makeEmpty 0
+        let world = World.initAndMakeEmpty 0
         let entity = World.makeEntity typeof<EntityDispatcher>.Name (Some DefaultEntityName) world
         let group = World.makeGroup typeof<GroupDispatcher>.Name (Some DefaultGroupName) world
         let screen = World.makeScreen typeof<ScreenDispatcher>.Name (Some DefaultScreenName) world
@@ -84,8 +77,7 @@ module WorldTests =
 
     let [<Fact>] gameSerializationWorks () =
         // TODO: make stronger assertions in here!!!
-        World.init ()
-        let world = World.makeEmpty 0
+        let world = World.initAndMakeEmpty 0
         let entity = World.makeEntity typeof<EntityDispatcher>.Name (Some DefaultEntityName) world
         let group = World.makeGroup typeof<GroupDispatcher>.Name (Some DefaultGroupName) world
         let screen = World.makeScreen typeof<ScreenDispatcher>.Name (Some DefaultScreenName) world