diff --git a/code/__defines/MC.dm b/code/__defines/MC.dm
index 57161ffac8..cb60e42bcd 100644
--- a/code/__defines/MC.dm
+++ b/code/__defines/MC.dm
@@ -67,14 +67,14 @@
 #define SUBSYSTEM_DEF(X) GLOBAL_REAL(SS##X, /datum/controller/subsystem/##X);\
 /datum/controller/subsystem/##X/New(){\
     NEW_SS_GLOBAL(SS##X);\
-    PreInit();\
+    OnNew();\
 }\
 /datum/controller/subsystem/##X
 
 #define PROCESSING_SUBSYSTEM_DEF(X) GLOBAL_REAL(SS##X, /datum/controller/subsystem/processing/##X);\
 /datum/controller/subsystem/processing/##X/New(){\
     NEW_SS_GLOBAL(SS##X);\
-    PreInit();\
+    OnNew();\
 }\
 /datum/controller/subsystem/processing/##X
 
diff --git a/code/controllers/controller.dm b/code/controllers/controller.dm
index c9d5f1e565..3c298fcf20 100644
--- a/code/controllers/controller.dm
+++ b/code/controllers/controller.dm
@@ -1,19 +1,41 @@
-/datum/controller
-	var/name
-	// The object used for the clickable stat() button.
-	var/obj/effect/statclick/statclick
+/// The display name of this controller.
+/datum/controller/var/name
 
+/// The atom used to provide a clickable stat line in the MC tab for this controller.
+/datum/controller/var/obj/effect/statclick/statclick
+
+
+// Do not implement any base behaviors here.
+/// Called to set up this controller.
 /datum/controller/proc/Initialize()
+	return
 
-//cleanup actions
+
+// Do not implement any base behaviors here.
+/// Called to clean up / finalize this controller.
 /datum/controller/proc/Shutdown()
+	return
 
-//when we enter dmm_suite.load_map
+
+// Do not implement any base behaviors here.
+/// Called when dmm_suite begins loading a map.
 /datum/controller/proc/StartLoadingMap()
+	return
 
-//when we exit dmm_suite.load_map
+
+// Do not implement any base behaviors here.
+/// Called when dmm_suite finishes loading a map.
 /datum/controller/proc/StopLoadingMap()
+	return
 
+
+// Do not implement any base behaviors here.
+/// To be called on the OLD instance if the controller fails in some way that requires it to be replaced.
 /datum/controller/proc/Recover()
+	return
 
+
+// Do not implement any base behaviors here.
+/// Called when an update to the stat line in the MC tab is requested.
 /datum/controller/proc/stat_entry()
+	return
diff --git a/code/controllers/master.dm b/code/controllers/master.dm
index 6b043b3f66..8110b78c8f 100644
--- a/code/controllers/master.dm
+++ b/code/controllers/master.dm
@@ -11,7 +11,7 @@
 GLOBAL_REAL(Master, /datum/controller/master) = new
 
 //THIS IS THE INIT ORDER
-//Master -> SSPreInit -> GLOB -> world -> config -> SSInit -> Failsafe
+//Master -> SSOnNew -> GLOB -> world -> config -> SSInit -> Failsafe
 //GOT IT MEMORIZED?
 
 /datum/controller/master
diff --git a/code/controllers/subsystem.dm b/code/controllers/subsystem.dm
index 65f2de418d..425b111565 100644
--- a/code/controllers/subsystem.dm
+++ b/code/controllers/subsystem.dm
@@ -52,13 +52,21 @@
 	return time
 
 
-/// Initializes the subsystem AFTER map load. The preferred initialization proc. Do not implement any base behaviors here.
+// Do not implement any base behaviors here.
+/// Initializes the subsystem exactly once, AFTER map load, run by the MC and passed REALTIMEOFDAY. The preferred initialization proc.
 /datum/controller/subsystem/Initialize(timeofday)
 	return
 
 
-/// Initializes the subsystem BEFORE map load. Called after recover, if recover is called.
-/datum/controller/subsystem/proc/PreInit()
+// Do not implement any base behaviors here.
+/// Called in subsystem/New if there is an existing instance of the subsystem, on the existing instance, before it is deleted.
+/datum/controller/subsystem/Recover()
+	return
+
+
+// Do not implement any base behaviors here.
+/// Called in subsystem/New - happens BEFORE map load, and ALSO every time the subsystem is Recovered, AFTER being Recovered.
+/datum/controller/subsystem/proc/OnNew()
 	return
 
 
diff --git a/code/controllers/subsystems/air.dm b/code/controllers/subsystems/air.dm
index 46e25dbf8a..a0429d8d0f 100644
--- a/code/controllers/subsystems/air.dm
+++ b/code/controllers/subsystems/air.dm
@@ -30,7 +30,7 @@ SUBSYSTEM_DEF(air)
 	// This is used to tell CI WHERE the edges are.
 	var/list/startup_active_edge_log = list()
 
-/datum/controller/subsystem/air/PreInit()
+/datum/controller/subsystem/air/OnNew()
 	air_master = src
 
 /datum/controller/subsystem/air/Initialize(timeofday)
diff --git a/code/controllers/subsystems/garbage.dm b/code/controllers/subsystems/garbage.dm
index 8688768c7d..273b1c99a3 100644
--- a/code/controllers/subsystems/garbage.dm
+++ b/code/controllers/subsystems/garbage.dm
@@ -30,7 +30,7 @@ SUBSYSTEM_DEF(garbage)
 	var/list/queues
 
 
-/datum/controller/subsystem/garbage/PreInit()
+/datum/controller/subsystem/garbage/OnNew()
 	queues = new(GC_QUEUE_COUNT)
 	pass_counts = new(GC_QUEUE_COUNT)
 	fail_counts = new(GC_QUEUE_COUNT)
diff --git a/code/controllers/subsystems/open_space.dm b/code/controllers/subsystems/open_space.dm
index 9d9efa0a2c..9b5808a197 100644
--- a/code/controllers/subsystems/open_space.dm
+++ b/code/controllers/subsystems/open_space.dm
@@ -23,7 +23,6 @@ SUBSYSTEM_DEF(open_space)
 
 /datum/controller/subsystem/open_space/Recover()
 	flags |= SS_NO_INIT // Make extra sure we don't initialize twice.
-	. = ..()
 
 /datum/controller/subsystem/open_space/fire(resumed, no_mc_tick)
 	// We use a different list so any additions to the update lists during a delay from MC_TICK_CHECK
diff --git a/code/controllers/subsystems/overlays.dm b/code/controllers/subsystems/overlays.dm
index 35dc2b52a6..307d9b8837 100644
--- a/code/controllers/subsystems/overlays.dm
+++ b/code/controllers/subsystems/overlays.dm
@@ -14,7 +14,7 @@ var/global/image/stringbro = new() // Temporarily super-global because of BYOND
 var/global/image/iconbro = new() // Temporarily super-global because of BYOND init order dumbness.
 var/global/image/appearance_bro = new() // Temporarily super-global because of BYOND init order dumbness.
 
-/datum/controller/subsystem/overlays/PreInit()
+/datum/controller/subsystem/overlays/OnNew()
 	overlay_icon_state_caches = list()
 	overlay_icon_cache = list()
 	queue = list()
diff --git a/code/controllers/subsystems/shuttles.dm b/code/controllers/subsystems/shuttles.dm
index e598632fea..342a281022 100644
--- a/code/controllers/subsystems/shuttles.dm
+++ b/code/controllers/subsystems/shuttles.dm
@@ -35,7 +35,7 @@ SUBSYSTEM_DEF(shuttles)
 
 	var/tmp/list/current_run                       // Shuttles remaining to process this fire() tick
 
-/datum/controller/subsystem/shuttles/PreInit()
+/datum/controller/subsystem/shuttles/OnNew()
 	global.shuttle_controller = src // TODO - Remove this! Change everything to point at SSshuttles intead
 
 /datum/controller/subsystem/shuttles/Initialize(timeofday)
diff --git a/code/controllers/subsystems/skybox.dm b/code/controllers/subsystems/skybox.dm
index 1707f80052..3df25b0f4f 100644
--- a/code/controllers/subsystems/skybox.dm
+++ b/code/controllers/subsystems/skybox.dm
@@ -12,7 +12,7 @@ SUBSYSTEM_DEF(skybox)
 	var/static/list/phase_shift_by_x = list()
 	var/static/list/phase_shift_by_y = list()
 
-/datum/controller/subsystem/skybox/PreInit()
+/datum/controller/subsystem/skybox/OnNew()
 	//Static
 	for (var/i in 0 to 25)
 		var/image/im = image('icons/turf/space_dust.dmi', "[i]")
@@ -60,8 +60,6 @@ SUBSYSTEM_DEF(skybox)
 	phase_shift_by_x = get_cross_shift_list(15)
 	phase_shift_by_y = get_cross_shift_list(15)
 
-	. = ..()
-
 
 /datum/controller/subsystem/skybox/proc/get_skybox(z)
 	if(!skybox_cache["[z]"])
diff --git a/code/controllers/subsystems/tgui.dm b/code/controllers/subsystems/tgui.dm
index 307f827d2b..51fb7865c5 100644
--- a/code/controllers/subsystems/tgui.dm
+++ b/code/controllers/subsystems/tgui.dm
@@ -22,7 +22,7 @@ SUBSYSTEM_DEF(tgui)
 	current.Cut()
 
 
-/datum/controller/subsystem/tgui/PreInit()
+/datum/controller/subsystem/tgui/OnNew()
 	base_html = file2text('tgui/packages/tgui/public/tgui.html')
 
 
diff --git a/code/controllers/subsystems/ticker.dm b/code/controllers/subsystems/ticker.dm
index f4bab1ca53..c8d2af60d4 100644
--- a/code/controllers/subsystems/ticker.dm
+++ b/code/controllers/subsystems/ticker.dm
@@ -47,7 +47,7 @@ SUBSYSTEM_DEF(ticker)
 
 // This global variable exists for legacy support so we don't have to rename every 'ticker' to 'SSticker' yet.
 var/global/datum/controller/subsystem/ticker/ticker
-/datum/controller/subsystem/ticker/PreInit()
+/datum/controller/subsystem/ticker/OnNew()
 	global.ticker = src // TODO - Remove this! Change everything to point at SSticker intead
 
 /datum/controller/subsystem/ticker/Initialize(timeofday)
diff --git a/code/controllers/subsystems/timer.dm b/code/controllers/subsystems/timer.dm
index a09bf1c94e..8ac3d243fb 100644
--- a/code/controllers/subsystems/timer.dm
+++ b/code/controllers/subsystems/timer.dm
@@ -28,7 +28,7 @@ SUBSYSTEM_DEF(timer)
 	var/static/last_invoke_warning = 0
 	var/static/bucket_auto_reset = TRUE
 
-/datum/controller/subsystem/timer/PreInit()
+/datum/controller/subsystem/timer/OnNew()
 	bucket_list.len = BUCKET_LEN
 	head_offset = world.time
 	bucket_resolution = world.tick_lag