that should be all of them. i hope this doesn't break custom shuttles again (#21902)

code/__HELPERS/areas.dm

@@ -36,7 +36,7 @@ GLOBAL_LIST_INIT(typecache_powerfailure_safe_areas, typecacheof(/area/engine/eng
 			if(break_if_found[checkT.type] || break_if_found[checkT.loc.type])
 				return FALSE
 			var/static/list/cardinal_cache = list("[NORTH]"=TRUE, "[EAST]"=TRUE, "[SOUTH]"=TRUE, "[WEST]"=TRUE)
-			if(!cardinal_cache["[dir]"] || checkT.blocks_air || !TURFS_CAN_SHARE(sourceT, checkT))
+			if(!cardinal_cache["[dir]"] || !TURFS_CAN_SHARE(sourceT, checkT))
 				continue
 			found_turfs += checkT // Since checkT is connected, add it to the list to be processed
 
@@ -226,13 +226,11 @@ GLOBAL_LIST_INIT(typecache_powerfailure_safe_areas, typecacheof(/area/engine/eng
 	// Now their turfs
 	var/list/turfs = list()
 	for(var/area/pull_from as anything in areas_to_pull)
-		var/list/our_turfs = pull_from.get_contained_turfs()
 		if (target_z == 0)
-			turfs += our_turfs
+			for (var/list/zlevel_turfs as anything in pull_from.get_zlevel_turf_lists())
+				turfs += zlevel_turfs
 		else
-			for(var/turf/turf_in_area as anything in our_turfs)
-				if(target_z == turf_in_area.z)
-					turfs += turf_in_area
+			turfs += pull_from.get_turfs_by_zlevel(target_z)
 	return turfs
 
 

code/__HELPERS/game.dm

@@ -1,4 +1,8 @@
-#define CULT_POLL_WAIT 2400
+///Time before being allowed to select a new cult leader again
+#define CULT_POLL_WAIT (240 SECONDS)
+
+/// Returns either the error landmark or the location of the room. Needless to say, if this is used, it means things have gone awry.
+#define GET_ERROR_ROOM ((locate(/obj/effect/landmark/error) in GLOB.landmarks_list) || locate(4,4,1))
 
 /proc/get_area_name(atom/X, format_text = FALSE, is_sensor = FALSE)
 	var/area/A = isarea(X) ? X : get_area(X)

code/controllers/subsystem/area_contents.dm

@@ -1,4 +1,4 @@
-#define ALLOWED_LOOSE_TURFS 500
+#define ALLOWED_LOOSE_TURFS 100
 /**
  * Responsible for managing the sizes of area.contained_turfs and area.turfs_to_uncontain
  * These lists do not check for duplicates, which is fine, but it also means they can balloon in size over time
@@ -17,8 +17,11 @@ SUBSYSTEM_DEF(area_contents)
 	var/total_clearing_from = 0
 	var/total_to_clear = 0
 	for(var/area/to_clear as anything in marked_for_clearing)
-		total_to_clear += length(to_clear.turfs_to_uncontain)
-		total_clearing_from += length(to_clear.contained_turfs)
+		for (var/area_zlevel in 1 to length(to_clear.turfs_to_uncontain_by_zlevel))
+			if (length(to_clear.turfs_to_uncontain_by_zlevel[area_zlevel]))
+				total_to_clear += length(to_clear.turfs_to_uncontain_by_zlevel[area_zlevel])
+				if (length(to_clear.turfs_by_zlevel) >= area_zlevel) //this should always be true, but stat_entry is no place for runtimes. fire() can handle that
+					total_clearing_from += length(to_clear.turfs_by_zlevel[area_zlevel])
 	msg = "A:[length(currentrun)] MR:[length(marked_for_clearing)] TC:[total_to_clear] CF:[total_clearing_from]"
 	return ..()
 
@@ -27,8 +30,11 @@ SUBSYSTEM_DEF(area_contents)
 	var/total_clearing_from = 0
 	var/total_to_clear = 0
 	for(var/area/to_clear as anything in marked_for_clearing)
-		total_to_clear += length(to_clear.turfs_to_uncontain)
-		total_clearing_from += length(to_clear.contained_turfs)
+		for (var/area_zlevel in 1 to length(to_clear.turfs_to_uncontain_by_zlevel))
+			if (length(to_clear.turfs_to_uncontain_by_zlevel[area_zlevel]))
+				total_to_clear += length(to_clear.turfs_to_uncontain_by_zlevel[area_zlevel])
+				if (length(to_clear.turfs_by_zlevel) >= area_zlevel) //this should always be true, but stat_entry is no place for runtimes. fire() can handle that
+					total_clearing_from += length(to_clear.turfs_by_zlevel[area_zlevel])
 	.["areas"] = length(currentrun)
 	.["marked_for_clearing"] = length(marked_for_clearing)
 	.["total_to_clear"] = total_to_clear
@@ -40,8 +46,10 @@ SUBSYSTEM_DEF(area_contents)
 
 	while(length(currentrun))
 		var/area/test = currentrun[length(currentrun)]
-		if(length(test.turfs_to_uncontain) > ALLOWED_LOOSE_TURFS)
+		for (var/area_zlevel in 1 to length(test.turfs_to_uncontain_by_zlevel))
+			if(length(test.turfs_to_uncontain_by_zlevel[area_zlevel]) > ALLOWED_LOOSE_TURFS)
 				marked_for_clearing |= test
+				break
 		currentrun.len--
 		if(MC_TICK_CHECK)
 			return
@@ -50,17 +58,27 @@ SUBSYSTEM_DEF(area_contents)
 	while(length(marked_for_clearing))
 		var/area/clear = marked_for_clearing[length(marked_for_clearing)]
 
+		for (var/area_zlevel in 1 to length(clear.turfs_to_uncontain_by_zlevel))
+			if (!length(clear.turfs_to_uncontain_by_zlevel[area_zlevel]))
+				continue
+			if (length(clear.turfs_by_zlevel) < area_zlevel)
+				stack_trace("[clear]([clear.type])'s turfs_by_zlevel is length [length(clear.turfs_by_zlevel)] but we are being asked to remove turfs from zlevel [area_zlevel] from it.")
+				clear.turfs_to_uncontain_by_zlevel[area_zlevel] = list()
+				continue
+
 			// The operation of cutting large lists can be expensive
 			// It scales almost directly with the size of the list we're cutting with
 			// Because of this, we're gonna stick to cutting 1 entry at a time
 			// There's no reason to batch it I promise, this is faster. No overtime too
 			var/amount_cut = 0
-		var/list/cut_from = clear.turfs_to_uncontain
+			var/list/cut_from = clear.turfs_to_uncontain_by_zlevel[area_zlevel]
 			for(amount_cut in 1 to length(cut_from))
-			clear.contained_turfs -= cut_from[amount_cut]
+				clear.turfs_by_zlevel[area_zlevel] -= cut_from[amount_cut]
 				if(MC_TICK_CHECK)
 					cut_from.Cut(1, amount_cut + 1)
 					return
 
-		clear.turfs_to_uncontain = list()
+		clear.turfs_to_uncontain_by_zlevel = list()
 		marked_for_clearing.len--
+
+#undef ALLOWED_LOOSE_TURFS

code/controllers/subsystem/job.dm

@@ -890,10 +890,16 @@ SUBSYSTEM_DEF(job)
 	M.forceMove(get_turf(src))
 
 /obj/structure/chair/JoinPlayerHere(mob/M, buckle)
+	. = ..()
 	// Placing a mob in a chair will attempt to buckle it, or else fall back to default.
 	if (buckle && isliving(M) && buckle_mob(M, FALSE, FALSE))
 		return
-	..()
+
+/obj/machinery/cryopod/JoinPlayerHere(mob/M, buckle)
+	. = ..()
+	open_machine()
+	if(iscarbon(M))
+		apply_effects_to_mob(M)
 
 /datum/controller/subsystem/job/proc/SendToLateJoin(mob/M, buckle = TRUE)
 	var/atom/destination
@@ -909,65 +915,49 @@ SUBSYSTEM_DEF(job)
 
 	//bad mojo
 	if(SSmapping.config.cryo_spawn)
-		var/area/shuttle/arrival/A = GLOB.areas_by_type[/area/crew_quarters/cryopods]
-		if(A)
-			var/list/pods = list()
-			var/list/unoccupied_pods = list()
-			for(var/obj/machinery/cryopod/pod in A)
-				pods |= pod
-				if(!pod.occupant)
-					unoccupied_pods |= pod
-			if(length(unoccupied_pods)) //if we have any unoccupied ones
-				destination = pick(unoccupied_pods)
-			else if(length(pods))
-				destination = pick(pods) //if they're all full somehow??
-			else //no pods at all
-				var/list/available = list()
-				for(var/turf/T in A)
-					if(!T.is_blocked_turf(TRUE))
-						available += T
-				if(length(available))
-					destination = pick(available)
-		if(destination)
-			destination.JoinPlayerHere(M, FALSE)
+		destination = get_cryo_spawn_points()
 	else
-			var/msg = "Unable to send mob [M] to late join (CRYOPODS)!"
-			message_admins(msg)
-			CRASH(msg)
+		destination = get_last_resort_spawn_points()
 	
-	else
-		var/area/shuttle/arrival/A = GLOB.areas_by_type[/area/shuttle/arrival]
-		if(A)
-			//first check if we can find a chair
-			var/obj/structure/chair/C = locate() in A
-			if(C)
-				C.JoinPlayerHere(M, buckle)
-				return
+	destination.JoinPlayerHere(M, buckle)
 
-			//last hurrah
-			var/list/avail = list()
-			for(var/turf/T in A)
-				if(!T.is_blocked_turf(TRUE))
-					avail += T
-			if(avail.len)
-				destination = pick(avail)
-				destination.JoinPlayerHere(M, FALSE)
-				return
+/datum/controller/subsystem/job/proc/get_cryo_spawn_points()
+	var/area/shuttle/arrival/cryo_spawn_area = GLOB.areas_by_type[/area/crew_quarters/cryopods]
+	if(!isnull(cryo_spawn_area))
+		var/list/turf/available_turfs = list()
+		for (var/list/zlevel_turfs as anything in cryo_spawn_area.get_zlevel_turf_lists())
+			for (var/turf/arrivals_turf as anything in zlevel_turfs)
+				var/obj/machinery/cryopod/spawn_pod = locate() in arrivals_turf
+				if(!isnull(spawn_pod))
+					return spawn_pod
+				if(arrivals_turf.is_blocked_turf(TRUE))
+					continue
+				available_turfs += arrivals_turf
 
-		//pick an open spot on arrivals and dump em
-		var/list/arrivals_turfs = shuffle(get_area_turfs(/area/shuttle/arrival))
-		if(arrivals_turfs.len)
-			for(var/turf/T in arrivals_turfs)
-				if(!T.is_blocked_turf(TRUE))
-					T.JoinPlayerHere(M, FALSE)
-					return
-			//last chance, pick ANY spot on arrivals and dump em
-			destination = arrivals_turfs[1]
-			destination.JoinPlayerHere(M, FALSE)
-		else
-			var/msg = "Unable to send mob [M] to late join!"
-			message_admins(msg)
-			CRASH(msg)
+		if(length(available_turfs))
+			return pick(available_turfs)
+
+	stack_trace("Unable to find cryo spawn point.")
+	return GET_ERROR_ROOM
+
+/datum/controller/subsystem/job/proc/get_last_resort_spawn_points()
+	var/area/shuttle/arrival/arrivals_area = GLOB.areas_by_type[/area/shuttle/arrival]
+	if(!isnull(arrivals_area))
+		var/list/turf/available_turfs = list()
+		for (var/list/zlevel_turfs as anything in arrivals_area.get_zlevel_turf_lists())
+			for (var/turf/arrivals_turf as anything in zlevel_turfs)
+				var/obj/structure/chair/shuttle_chair = locate() in arrivals_turf
+				if(!isnull(shuttle_chair))
+					return shuttle_chair
+				if(arrivals_turf.is_blocked_turf(TRUE))
+					continue
+				available_turfs += arrivals_turf
+
+		if(length(available_turfs))
+			return pick(available_turfs)
+
+	stack_trace("Unable to find last resort spawn point.")
+	return GET_ERROR_ROOM
 
 ///Lands specified mob at a random spot in the hallways
 /datum/controller/subsystem/job/proc/DropLandAtRandomHallwayPoint(mob/living/living_mob)

code/controllers/subsystem/mapping.dm

@@ -231,7 +231,7 @@ SUBSYSTEM_DEF(mapping)
 	// Cache for sonic speed
 	var/list/unused_turfs = src.unused_turfs
 	var/list/world_contents = GLOB.areas_by_type[world.area].contents
-	var/list/world_turf_contents = GLOB.areas_by_type[world.area].contained_turfs
+	var/list/world_turf_contents_by_z = GLOB.areas_by_type[world.area].turfs_by_zlevel
 	var/list/lists_to_reserve = src.lists_to_reserve
 	var/index = 0
 	while(index < length(lists_to_reserve))
@@ -247,10 +247,12 @@ SUBSYSTEM_DEF(mapping)
 			LAZYINITLIST(unused_turfs["[T.z]"])
 			unused_turfs["[T.z]"] |= T
 			var/area/old_area = T.loc
-			old_area.turfs_to_uncontain += T
+			LISTASSERTLEN(old_area.turfs_to_uncontain_by_zlevel, T.z, list())
+			old_area.turfs_to_uncontain_by_zlevel[T.z] += T
 			T.turf_flags = UNUSED_RESERVATION_TURF
 			world_contents += T
-			world_turf_contents += T
+			LISTASSERTLEN(world_turf_contents_by_z, T.z, list())
+			world_turf_contents_by_z[T.z] += T
 			packet.len--
 			packetlen = length(packet)
 
@@ -874,12 +876,14 @@ GLOBAL_LIST_EMPTY(the_station_areas)
 	// Faster
 	if(space_guaranteed)
 		var/area/global_area = GLOB.areas_by_type[world.area]
-		global_area.contained_turfs += Z_TURFS(z_level)
+		LISTASSERTLEN(global_area.turfs_by_zlevel, z_level, list())
+		global_area.turfs_by_zlevel[z_level] = Z_TURFS(z_level)
 		return
 
 	for(var/turf/to_contain as anything in Z_TURFS(z_level))
 		var/area/our_area = to_contain.loc
-		our_area.contained_turfs += to_contain
+		LISTASSERTLEN(our_area.turfs_by_zlevel, z_level, list())
+		our_area.turfs_by_zlevel[z_level] += to_contain
 
 /datum/controller/subsystem/mapping/proc/update_plane_tracking(datum/space_level/update_with)
 	// We're essentially going to walk down the stack of connected z levels, and set their plane offset as we go

code/controllers/subsystem/shuttle.dm

@@ -616,13 +616,16 @@ SUBSYSTEM_DEF(shuttle)
 	if(!midpoint)
 		qdel(proposal)
 		return FALSE
+	
 	var/area/old_area = midpoint.loc
-	old_area.turfs_to_uncontain += proposal.reserved_turfs
+	LISTASSERTLEN(old_area.turfs_to_uncontain_by_zlevel, bottomleft.z, list())
+	old_area.turfs_to_uncontain_by_zlevel[bottomleft.z] += proposal.reserved_turfs
 	
 	var/area/shuttle/transit/new_area = new()
 	new_area.parallax_movedir = travel_dir
 	new_area.contents = proposal.reserved_turfs
-	new_area.contained_turfs = proposal.reserved_turfs
+	LISTASSERTLEN(new_area.turfs_by_zlevel, bottomleft.z, list())
+	new_area.turfs_by_zlevel[bottomleft.z] = proposal.reserved_turfs
 	
 	var/obj/docking_port/stationary/transit/new_transit_dock = new(midpoint)
 	new_transit_dock.reserved_area = proposal

code/datums/diseases/wizarditis.dm

@@ -91,27 +91,27 @@ STI KALY - blind
 	if(!theareas||!theareas.len)
 		return
 
-	var/area/thearea = pick(theareas)
+	var/area/last_chosen_area_name = pick(theareas)
 
 	var/list/L = list()
-	for(var/turf/T in get_area_turfs(thearea.type))
-		if(T.z != affected_mob.z)
+	for(var/turf/possible_destination as anything in get_area_turfs(GLOB.teleportlocs[last_chosen_area_name]))
+		if(possible_destination.z != affected_mob.z)
 			continue
-		if(T.name == "space")
+		if(isspaceturf(possible_destination))
 			continue
-		if(!T.density)
+		if(!possible_destination.density)
 			var/clear = 1
-			for(var/obj/O in T)
+			for(var/obj/O in possible_destination)
 				if(O.density)
 					clear = 0
 					break
 			if(clear)
-				L+=T
+				L += possible_destination
 
 	if(!L)
 		return
 
-	affected_mob.say("SCYAR NILA [uppertext(thearea.name)]!", forced = "wizarditis teleport")
+	affected_mob.say("SCYAR NILA [uppertext(last_chosen_area_name.name)]!", forced = "wizarditis teleport")
 	affected_mob.forceMove(pick(L))
 
 	return

code/datums/mapgen/dungeon_generators/dungeon_room.dm

@@ -193,9 +193,6 @@
 	for(var/turf/room_turf in (interior + exterior))
 		var/area/old_area = get_area(room_turf)
 		if(area_ref != old_area && !generator_ref.areas_included.Find(old_area))
-			area_ref.contents += room_turf
-			area_ref.contained_turfs += room_turf
-			old_area.turfs_to_uncontain += room_turf
 			room_turf.change_area(old_area, area_ref)
 
 	return TRUE

code/game/area/areas.dm

@@ -13,14 +13,16 @@
 	mouse_opacity = MOUSE_OPACITY_TRANSPARENT
 	invisibility = INVISIBILITY_LIGHTING
 
-	/// List of all turfs currently inside this area. Acts as a filtered bersion of area.contents
-	/// For faster lookup (area.contents is actually a filtered loop over world)
+	/// List of all turfs currently inside this area as nested lists indexed by zlevel.
+	/// Acts as a filtered version of area.contents For faster lookup
+	/// (area.contents is actually a filtered loop over world)
 	/// Semi fragile, but it prevents stupid so I think it's worth it
-	var/list/turf/contained_turfs = list()
-	/// Contained turfs is a MASSIVE list, so rather then adding/removing from it each time we have a problem turf
+	var/list/list/turf/turfs_by_zlevel = list()
+	/// turfs_by_z_level can hold MASSIVE lists, so rather then adding/removing from it each time we have a problem turf
 	/// We should instead store a list of turfs to REMOVE from it, then hook into a getter for it
 	/// There is a risk of this and contained_turfs leaking, so a subsystem will run it down to 0 incrementally if it gets too large
-	var/list/turf/turfs_to_uncontain = list()
+	/// This uses the same nested list format as turfs_by_zlevel
+	var/list/list/turf/turfs_to_uncontain_by_zlevel = list()
 
 	var/area_flags = NONE
 
@@ -249,33 +251,99 @@ GLOBAL_LIST_EMPTY(teleportlocs)
 			turfs += T
 		map_generator.generate_terrain(turfs, src)
 
-/area/proc/get_contained_turfs()
-	if(length(turfs_to_uncontain))
+/// Returns the highest zlevel that this area contains turfs for
+/area/proc/get_highest_zlevel()
+	for (var/area_zlevel in length(turfs_by_zlevel) to 1 step -1)
+		if (length(turfs_to_uncontain_by_zlevel) >= area_zlevel)
+			if (length(turfs_by_zlevel[area_zlevel]) - length(turfs_to_uncontain_by_zlevel[area_zlevel]) > 0)
+				return area_zlevel
+		else
+			if (length(turfs_by_zlevel[area_zlevel]))
+				return area_zlevel
+	return 0
+
+/// Returns a nested list of lists with all turfs split by zlevel.
+/// only zlevels with turfs are returned. The order of the list is not guaranteed.
+/area/proc/get_zlevel_turf_lists()
+	if(length(turfs_to_uncontain_by_zlevel))
 		cannonize_contained_turfs()
-	return contained_turfs
+
+	var/list/zlevel_turf_lists = list()
+
+	for (var/list/zlevel_turfs as anything in turfs_by_zlevel)
+		if (length(zlevel_turfs))
+			zlevel_turf_lists += list(zlevel_turfs)
+
+	return zlevel_turf_lists
+
+/// Returns a list with all turfs in this zlevel.
+/area/proc/get_turfs_by_zlevel(zlevel)
+	if (length(turfs_to_uncontain_by_zlevel) >= zlevel && length(turfs_to_uncontain_by_zlevel[zlevel]))
+		cannonize_contained_turfs_by_zlevel(zlevel)
+
+	if (length(turfs_by_zlevel) < zlevel)
+		return list()
+
+	return turfs_by_zlevel[zlevel]
+
+
+/// Merges a list containing all of the turfs zlevel lists from get_zlevel_turf_lists inside one list. Use get_zlevel_turf_lists() or get_turfs_by_zlevel() unless you need all the turfs in one list to avoid generating large lists
+/area/proc/get_turfs_from_all_zlevels()
+	. = list()
+	for (var/list/zlevel_turfs as anything in get_zlevel_turf_lists())
+		. += zlevel_turfs
 
 /// Ensures that the contained_turfs list properly represents the turfs actually inside us
-/area/proc/cannonize_contained_turfs()
+/area/proc/cannonize_contained_turfs_by_zlevel(zlevel_to_clean, _autoclean = TRUE)
 	// This is massively suboptimal for LARGE removal lists
 	// Try and keep the mass removal as low as you can. We'll do this by ensuring
 	// We only actually add to contained turfs after large changes (Also the management subsystem)
 	// Do your damndest to keep turfs out of /area/space as a stepping stone
-	// That sucker gets HUGE and will make this take actual tens of seconds if you stuff turfs_to_uncontain
-	contained_turfs -= turfs_to_uncontain
-	turfs_to_uncontain = list()
+	// That sucker gets HUGE and will make this take actual seconds
+	if (zlevel_to_clean <= length(turfs_by_zlevel) && zlevel_to_clean <= length(turfs_to_uncontain_by_zlevel))
+		turfs_by_zlevel[zlevel_to_clean] -= turfs_to_uncontain_by_zlevel[zlevel_to_clean]
+
+	if (!_autoclean) // Removes empty lists from the end of this list
+		turfs_to_uncontain_by_zlevel[zlevel_to_clean] = list()
+		return
+
+	var/new_length = length(turfs_to_uncontain_by_zlevel)
+	// Walk backwards thru the list
+	for (var/i in length(turfs_to_uncontain_by_zlevel) to 0 step -1)
+		if (i && length(turfs_to_uncontain_by_zlevel[i]))
+			break // Stop the moment we find a useful list
+		new_length = i
+
+	if (new_length < length(turfs_to_uncontain_by_zlevel))
+		turfs_to_uncontain_by_zlevel.len = new_length
+
+	if (new_length >= zlevel_to_clean)
+		turfs_to_uncontain_by_zlevel[zlevel_to_clean] = list()
+
+
+/// Ensures that the contained_turfs list properly represents the turfs actually inside us
+/area/proc/cannonize_contained_turfs()
+	for (var/area_zlevel in 1 to length(turfs_to_uncontain_by_zlevel))
+		cannonize_contained_turfs_by_zlevel(area_zlevel, _autoclean = FALSE)
+
+	turfs_to_uncontain_by_zlevel = list()
+
 
 /// Returns TRUE if we have contained turfs, FALSE otherwise
 /area/proc/has_contained_turfs()
-	return length(contained_turfs) - length(turfs_to_uncontain) > 0
+	for (var/area_zlevel in 1 to length(turfs_by_zlevel))
+		if (length(turfs_to_uncontain_by_zlevel) >= area_zlevel)
+			if (length(turfs_by_zlevel[area_zlevel]) - length(turfs_to_uncontain_by_zlevel[area_zlevel]) > 0)
+				return TRUE
+		else
+			if (length(turfs_by_zlevel[area_zlevel]))
+				return TRUE
+	return FALSE
 
 /**
  * Register this area as belonging to a z level
  *
  * Ensures the item is added to the SSmapping.areas_in_z list for this z
-  *
-  * It also goes through every item in this areas contents and sets the area level z to it
-  * breaking the exat first time it does this, this seems crazy but what would I know, maybe
-  * areas don't have a valid z themself or something
  */
 /area/proc/reg_in_areas_in_z()
 	if(!has_contained_turfs())
@@ -304,10 +372,23 @@ GLOBAL_LIST_EMPTY(teleportlocs)
 /area/Destroy()
 	if(GLOB.areas_by_type[type] == src)
 		GLOB.areas_by_type[type] = null
+	//this is not initialized until get_sorted_areas() is called so we have to do a null check
+	if(!isnull(GLOB.sortedAreas))
 		GLOB.sortedAreas -= src
+	//just for sanity sake cause why not
+	if(!isnull(GLOB.areas))
 		GLOB.areas -= src
+	
+	//YOG
+	if(!isnull(GLOB.delta_areas))
 		GLOB.delta_areas -= src
+	
+	//machinery cleanup
 	STOP_PROCESSING(SSobj, src)
+	//turf cleanup
+	turfs_by_zlevel = null
+	turfs_to_uncontain_by_zlevel = null
+	//parent cleanup
 	return ..()
 
 /**
@@ -780,7 +861,8 @@ GLOBAL_LIST_EMPTY(teleportlocs)
 	if(outdoors)
 		return FALSE
 	areasize = 0
-	for(var/turf/open/T in get_contained_turfs())
+	for(var/list/zlevel_turfs as anything in get_zlevel_turf_lists())
+		for(var/turf/open/thisvarisunused in zlevel_turfs)
 			areasize++
 
 /**

code/game/machinery/cryopod.dm

@@ -450,12 +450,6 @@ GLOBAL_LIST_EMPTY(cryopod_computers)
 	message_admins("[key_name_admin(target)] entered a stasis pod. (<A HREF='?_src_=holder;[HrefToken()];adminplayerobservecoodjump=1;X=[x];Y=[y];Z=[z]'>JMP</a>)")
 	add_fingerprint(target)
 
-/obj/machinery/cryopod/JoinPlayerHere(mob/M, buckle)
-	. = ..()
-	open_machine()
-	if(iscarbon(M))
-		apply_effects_to_mob(M)
-
 /obj/machinery/cryopod/proc/apply_effects_to_mob(mob/living/carbon/sleepyhead)
 	to_chat(sleepyhead, span_boldnotice("You begin to wake from cryosleep..."))
 	sleepyhead.set_nutrition(200)

code/game/objects/items/blueprints.dm

@@ -227,17 +227,22 @@
 	return TRUE
 
 
-/proc/set_area_machinery_title(area/A, title, oldtitle)
+/proc/set_area_machinery_title(area/area, title, oldtitle)
 	if(!oldtitle) // or replacetext goes to infinite loop
 		return
-	for(var/obj/machinery/airalarm/M in A)
-		M.name = replacetext(M.name,oldtitle,title)
-	for(var/obj/machinery/power/apc/M in A)
-		M.name = replacetext(M.name,oldtitle,title)
-	for(var/obj/machinery/atmospherics/components/unary/vent_scrubber/M in A)
-		M.name = replacetext(M.name,oldtitle,title)
-	for(var/obj/machinery/atmospherics/components/unary/vent_pump/M in A)
-		M.name = replacetext(M.name,oldtitle,title)
-	for(var/obj/machinery/door/M in A)
-		M.name = replacetext(M.name,oldtitle,title)
+
+	//stuff tied to the area to rename
+	var/static/list/to_rename = typecacheof(list(
+		/obj/machinery/airalarm,
+		/obj/machinery/atmospherics/components/unary/vent_scrubber,
+		/obj/machinery/atmospherics/components/unary/vent_pump,
+		/obj/machinery/door,
+		/obj/machinery/firealarm,
+		/obj/machinery/light_switch,
+		/obj/machinery/power/apc,
+	))
+	for (var/list/zlevel_turfs as anything in area.get_zlevel_turf_lists())
+		for (var/turf/area_turf as anything in zlevel_turfs)
+			for(var/obj/machine as anything in typecache_filter_list(area_turf.contents, to_rename))
+				machine.name = replacetext(machine.name, oldtitle, title)
 	//TODO: much much more. Unnamed airlocks, cameras, etc.

code/game/turfs/turf.dm

@@ -231,14 +231,17 @@ GLOBAL_LIST_EMPTY(station_turfs)
 		return
 	user.Move_Pulled(src)
 
+/// Call to move a turf from its current area to a new one
 /turf/proc/change_area(area/old_area, area/new_area)
 	//dont waste our time
 	if(old_area == new_area)
 		return
 
 	//move the turf
-	old_area.turfs_to_uncontain += src
-	new_area.contained_turfs += src
+	LISTASSERTLEN(old_area.turfs_to_uncontain_by_zlevel, z, list())
+	LISTASSERTLEN(new_area.turfs_by_zlevel, z, list())
+	old_area.turfs_to_uncontain_by_zlevel[z] += src
+	new_area.turfs_by_zlevel[z] += src
 	new_area.contents += src
 
 	//changes to make after turf has moved

code/game/world.dm

@@ -365,10 +365,14 @@ GLOBAL_VAR(restart_counter)
 	if(!map_load_z_cutoff)
 		return
 	var/area/global_area = GLOB.areas_by_type[world.area] // We're guaranteed to be touching the global area, so we'll just do this
+	LISTASSERTLEN(global_area.turfs_by_zlevel, map_load_z_cutoff, list())
+	for (var/zlevel in 1 to map_load_z_cutoff)
 		var/list/to_add = block(
-		locate(old_max + 1, 1, 1),
-		locate(maxx, maxy, map_load_z_cutoff))
-	global_area.contained_turfs += to_add
+			locate(old_max + 1, 1, zlevel),
+			locate(maxx, maxy, zlevel))
+
+		global_area.turfs_by_zlevel[zlevel] += to_add
+
 
 /world/proc/increase_max_y(new_maxy, map_load_z_cutoff = maxz)
 	if(new_maxy <= maxy)
@@ -378,10 +382,12 @@ GLOBAL_VAR(restart_counter)
 	if(!map_load_z_cutoff)
 		return
 	var/area/global_area = GLOB.areas_by_type[world.area] // We're guarenteed to be touching the global area, so we'll just do this
+	LISTASSERTLEN(global_area.turfs_by_zlevel, map_load_z_cutoff, list())
+	for (var/zlevel in 1 to map_load_z_cutoff)
 		var/list/to_add = block(
 			locate(1, old_maxy + 1, 1),
 			locate(maxx, maxy, map_load_z_cutoff))
-	global_area.contained_turfs += to_add
+		global_area.turfs_by_zlevel[zlevel] += to_add
 
 /world/proc/incrementMaxZ()
 	maxz++

code/modules/admin/verbs/adminjump.dm

@@ -10,10 +10,10 @@
 		return
 
 	var/list/turfs = list()
-	for(var/turf/T in A)
-		if(T.density)
-			continue
-		turfs.Add(T)
+	for (var/list/zlevel_turfs as anything in A.get_zlevel_turf_lists())
+		for (var/turf/area_turf as anything in zlevel_turfs)
+			if(!area_turf.density)
+				turfs.Add(area_turf)
 
 	var/turf/T = pick(turfs)
 	if(!T)

code/modules/antagonists/bloodsuckers/structures/bloodsucker_crypt.dm

@@ -521,7 +521,7 @@
 	var/area/current_area = get_area(src)
 	if(current_area == bloodsuckerdatum.bloodsucker_lair_area)
 		return
-	bloodsuckerdatum.bloodsucker_lair_area.contained_turfs += current_area.contained_turfs
+	bloodsuckerdatum.bloodsucker_lair_area.turfs_by_zlevel[z] += current_area.turfs_by_zlevel[z]
 
 /obj/structure/bloodsucker/bloodstatue/command/unbolt()
 	. = ..()
@@ -529,7 +529,7 @@
 	var/area/current_area = get_area(src)
 	if(current_area == bloodsuckerdatum.bloodsucker_lair_area)
 		return
-	bloodsuckerdatum.bloodsucker_lair_area.turfs_to_uncontain += current_area.contained_turfs
+	bloodsuckerdatum.bloodsucker_lair_area.turfs_to_uncontain_by_zlevel[z] += current_area.turfs_by_zlevel[z]
 
 /obj/structure/bloodsucker/bloodstatue/greytide
 	name = "greytider bust"

code/modules/cargo/expressconsole.dm

@@ -180,7 +180,7 @@
 						if (!landingzone)
 							WARNING("[src] couldnt find a Quartermaster/Storage (aka cargobay) area on the station, and as such it has set the supplypod landingzone to the area it resides in.")
 							landingzone = get_area(src)
-						for(var/turf/open/floor/T in landingzone.get_contained_turfs())//uses default landing zone
+						for(var/turf/open/floor/T in landingzone.get_turfs_from_all_zlevels())//uses default landing zone
 							if(T.is_blocked_turf())
 								continue
 							LAZYADD(empty_turfs, T)
@@ -197,7 +197,7 @@
 			else
 				if(SO.pack.get_cost() * (0.72*MAX_EMAG_ROCKETS) <= points_to_check) // bulk discount :^)
 					landingzone = GLOB.areas_by_type[pick(GLOB.the_station_areas)]  //override default landing zone
-					for(var/turf/open/floor/T in landingzone.get_contained_turfs())
+					for(var/turf/open/floor/T in landingzone.get_turfs_from_all_zlevels())
 						if(T.is_blocked_turf())
 							continue
 						LAZYADD(empty_turfs, T)

code/modules/clothing/glasses/engine_goggles.dm

@@ -108,7 +108,7 @@
 		return
 	var/list/shuttle_areas = port.shuttle_areas
 	for(var/area/region as anything in shuttle_areas)
-		for(var/turf/place as anything in region.get_contained_turfs())
+		for(var/turf/place as anything in region.get_turfs_from_all_zlevels())
 			if(get_dist(user, place) > 7)
 				continue
 			var/image/pic

code/modules/events/aurora_caelus.dm

@@ -51,7 +51,7 @@
 	set_starlight(aurora_color)
 
 	for(var/area/crew_quarters/kitchen/affected_area in GLOB.areas)
-		for(var/turf/open/kitchen_floor in affected_area.get_contained_turfs())
+		for(var/turf/open/kitchen_floor in affected_area.get_turfs_from_all_zlevels())
 			kitchen_floor.set_light(l_color = aurora_color)
 
 /datum/round_event/aurora_caelus/end()
@@ -107,9 +107,9 @@
 		var/walked_range = LERP(start_range, end_range, i/5)
 		var/walked_power = LERP(start_power, end_power, i/5)
 		for(var/area/crew_quarters/kitchen/affected_area in GLOB.areas)
-			for(var/turf/open/kitchen_floor in affected_area.get_contained_turfs())
+			for(var/turf/open/kitchen_floor in affected_area.get_turfs_from_all_zlevels())
 				kitchen_floor.set_light(walked_range, walked_power, walked_color)
 		sleep(8 SECONDS)
 	for(var/area/crew_quarters/kitchen/affected_area in GLOB.areas)
-		for(var/turf/open/kitchen_floor in affected_area.get_contained_turfs())
+		for(var/turf/open/kitchen_floor in affected_area.get_turfs_from_all_zlevels())
 			kitchen_floor.set_light(end_range, end_power, end_color)

code/modules/events/spacevine.dm

@@ -14,7 +14,7 @@
 	var/obj/structure/spacevine/SV = new()
 
 	for(var/area/maintenance/A in GLOB.areas)
-		for(var/turf/F as anything in A.get_contained_turfs())
+		for(var/turf/F in A.get_turfs_from_all_zlevels())
 			if(F.Enter(SV))
 				turfs += F
 

code/modules/lighting/lighting_area.dm

@@ -51,8 +51,9 @@
 	UnregisterSignal(SSdcs, COMSIG_STARLIGHT_COLOR_CHANGED)
 	var/list/z_offsets = SSmapping.z_level_to_plane_offset
 	if(length(lighting_effects) > 1)
-		for(var/turf/T as anything in get_contained_turfs())
-			if(z_offsets[T.z])
+		for(var/area_zlevel in 1 to get_highest_zlevel())
+			if(z_offsets[area_zlevel])
+				for(var/turf/T as anything in get_turfs_by_zlevel(area_zlevel))
 					T.cut_overlay(lighting_effects[z_offsets[T.z] + 1])
 	cut_overlay(lighting_effects[1])
 	lighting_effects = null
@@ -91,17 +92,18 @@
 
 	add_overlay(lighting_effects[1])
 	var/list/z_offsets = SSmapping.z_level_to_plane_offset
-	if(length(lighting_effects) > 1)
-		// This inside loop is EXTREMELY hot because it's run by space tiles. Don't want no part in that
-		for(var/turf/T as anything in get_contained_turfs())
-			T.luminosity = 1
+	for (var/area_zlevel in 1 to get_highest_zlevel())
 		// We will only add overlays to turfs not on the first z layer, because that's a significantly lesser portion
 		// And we need to do them separate, or lighting will go fuckey
-			if(z_offsets[T.z])
-				T.add_overlay(lighting_effects[z_offsets[T.z] + 1])
+		// This inside loop is EXTREMELY hot because it's run by space tiles, so we do the if check once on the outside
+		if(length(lighting_effects) > 1 && z_offsets[area_zlevel])
+			var/lighting_effect_to_add = lighting_effects[z_offsets[area_zlevel] + 1]
+			for(var/turf/area_turf as anything in get_turfs_by_zlevel(area_zlevel))
+				area_turf.luminosity = 1
+				area_turf.add_overlay(lighting_effect_to_add)
 		else
-		for(var/turf/T as anything in get_contained_turfs())
-			T.luminosity = 1
+			for(var/turf/area_turf as anything in get_turfs_by_zlevel(area_zlevel))
+				area_turf.luminosity = 1
 
 	area_has_base_lighting = TRUE
 

code/modules/lighting/lighting_setup.dm

@@ -1,12 +1,12 @@
 
 /proc/create_all_lighting_objects()
-	for(var/area/A as anything in GLOB.areas)
-		if(!A.static_lighting)
+	for(var/area/area as anything in GLOB.areas)
+		if(!area.static_lighting)
 			continue
-
-		for(var/turf/T as anything in A.get_contained_turfs())
-			if(T.space_lit)
+		for (var/list/zlevel_turfs as anything in area.get_zlevel_turf_lists())
+			for(var/turf/area_turf as anything in zlevel_turfs)
+				if(area_turf.space_lit)
 					continue
-			new /datum/lighting_object(T)
+				new /datum/lighting_object(area_turf)
 			CHECK_TICK
 		CHECK_TICK

code/modules/mapping/reader.dm

@@ -931,8 +931,10 @@ GLOBAL_LIST_EMPTY(map_model_default)
 
 		if(!new_z)
 			old_area = crds.loc
-			old_area.turfs_to_uncontain += crds
-			area_instance.contained_turfs.Add(crds)
+			LISTASSERTLEN(old_area.turfs_to_uncontain_by_zlevel, crds.z, list())
+			LISTASSERTLEN(area_instance.turfs_by_zlevel, crds.z, list())
+			old_area.turfs_to_uncontain_by_zlevel[crds.z] += crds
+			area_instance.turfs_by_zlevel[crds.z] += crds
 		area_instance.contents.Add(crds)
 
 		if(GLOB.use_preloader)

code/modules/mapping/space_management/space_reservation.dm

@@ -82,10 +82,10 @@
 		var/area/misc/cordon/cordon_area = GLOB.areas_by_type[/area/misc/cordon] || new
 		var/area/old_area = cordon_turf.loc
 
-		//LISTASSERTLEN(old_area.turfs_to_uncontain, cordon_turf.z, list())
-		//LISTASSERTLEN(cordon_area.contained_turfs, cordon_turf.z, list())
-		old_area.turfs_to_uncontain += cordon_turf
-		cordon_area.contained_turfs += cordon_turf
+		LISTASSERTLEN(old_area.turfs_to_uncontain_by_zlevel, cordon_turf.z, list())
+		LISTASSERTLEN(cordon_area.turfs_by_zlevel, cordon_turf.z, list())
+		old_area.turfs_to_uncontain_by_zlevel[cordon_turf.z] += cordon_turf
+		cordon_area.turfs_by_zlevel[cordon_turf.z] += cordon_turf
 		cordon_area.contents += cordon_turf
 
 		// Its no longer unused, but its also not "used"

code/modules/research/xenobiology/xenobiology.dm

@@ -1075,9 +1075,10 @@
 
 /obj/item/areaeditor/blueprints/slime/edit_area()
 	..()
-	var/area/A = get_area(src)
-	for(var/turf/T in A)
-		T.remove_atom_colour(WASHABLE_COLOUR_PRIORITY)
-		T.add_atom_colour("#2956B2", FIXED_COLOUR_PRIORITY)
-	A.xenobiology_compatible = TRUE
+	var/area/area = get_area(src)
+	for (var/list/zlevel_turfs as anything in area.get_zlevel_turf_lists())
+		for(var/turf/area_turf as anything in zlevel_turfs)
+			area_turf.remove_atom_colour(WASHABLE_COLOUR_PRIORITY)
+			area_turf.add_atom_colour("#2956B2", FIXED_COLOUR_PRIORITY)
+	area.xenobiology_compatible = TRUE
 	qdel(src)

code/modules/security_levels/keycard_authentication.dm

@@ -133,21 +133,23 @@ GLOBAL_DATUM_INIT(keycard_events, /datum/events, new)
 
 GLOBAL_VAR_INIT(emergency_access, FALSE)
 /proc/make_maint_all_access()
-	for(var/area/maintenance/A in GLOB.areas)
-		for(var/turf/in_area as anything in A.get_contained_turfs())
-			for(var/obj/machinery/door/airlock/D in in_area)
-				D.emergency = TRUE
-				D.update_icon(state=ALL, override=0)
+	for(var/area/maintenance/area in GLOB.areas)
+		for (var/list/zlevel_turfs as anything in area.get_zlevel_turf_lists())
+			for(var/turf/area_turf as anything in zlevel_turfs)
+				for(var/obj/machinery/door/airlock/airlock in area_turf)
+					airlock.emergency = TRUE
+					airlock.update_icon(ALL, 0)
 	minor_announce("Access restrictions on maintenance and external airlocks have been lifted.", "Attention! Station-wide emergency declared!",1)
 	GLOB.emergency_access = TRUE
 	SSblackbox.record_feedback("nested tally", "keycard_auths", 1, list("emergency maintenance access", "enabled"))
 
 /proc/revoke_maint_all_access()
-	for(var/area/maintenance/A in GLOB.areas)
-		for(var/turf/in_area as anything in A.get_contained_turfs())
-			for(var/obj/machinery/door/airlock/D in in_area)
-				D.emergency = FALSE
-				D.update_icon(state=ALL, override=0)
+	for(var/area/maintenance/area in GLOB.areas)
+		for (var/list/zlevel_turfs as anything in area.get_zlevel_turf_lists())
+			for(var/turf/area_turf as anything in zlevel_turfs)
+				for(var/obj/machinery/door/airlock/airlock in area_turf)
+					airlock.emergency = FALSE
+					airlock.update_icon(ALL, 0)
 	minor_announce("Access restrictions in maintenance areas have been restored.", "Attention! Station-wide emergency rescinded:")
 	GLOB.emergency_access = FALSE
 	SSblackbox.record_feedback("nested tally", "keycard_auths", 1, list("emergency maintenance access", "disabled"))

code/modules/shuttle/custom_shuttle.dm

@@ -127,10 +127,10 @@
 	calculated_non_operational_thrusters = 0
 	//Calculate all the data
 	var/list/areas = M.shuttle_areas
-	for(var/shuttleArea in areas)
-		for(var/turf/T in shuttleArea)
+	for(var/area/shuttle_area in areas)
+		for(var/turf/T in shuttle_area.get_turfs_by_zlevel(z))
 			calculated_mass += 1
-		for(var/obj/machinery/shuttle/engine/E in shuttleArea)
+		for(var/obj/machinery/shuttle/engine/E in shuttle_area)
 			E.check_setup()
 			if(!E.thruster_active)	//Skipover thrusters with no valid heater
 				calculated_non_operational_thrusters ++

code/modules/shuttle/navigation_computer.dm

@@ -96,7 +96,8 @@
 	the_eye.setDir(shuttle_port.dir)
 	var/turf/origin = locate(shuttle_port.x + x_offset, shuttle_port.y + y_offset, shuttle_port.z)
 	for(var/area/shuttle_area as anything in shuttle_port.shuttle_areas)
-		for(var/turf/shuttle_turf as anything in shuttle_area.get_contained_turfs())
+		for (var/list/zlevel_turfs as anything in shuttle_area.get_zlevel_turf_lists())
+			for(var/turf/shuttle_turf as anything in zlevel_turfs)
 				if(shuttle_turf.z != origin.z)
 					continue
 				var/image/I = image('icons/effects/alphacolors.dmi', origin, "red")

code/modules/shuttle/shuttle.dm

@@ -513,8 +513,9 @@
 		var/min_y = -1
 		var/max_x = WORLDMAXX_CUTOFF
 		var/max_y = WORLDMAXY_CUTOFF
-		for(var/area/area as anything in shuttle_areas)
-			for(var/turf/turf as anything in area.get_contained_turfs())
+		for(var/area/shuttle_area as anything in shuttle_areas)
+			for (var/list/zlevel_turfs as anything in shuttle_area.get_zlevel_turf_lists())
+				for(var/turf/turf as anything in zlevel_turfs)
 					min_x = max(turf.x, min_x)
 					max_x = min(turf.x, max_x)
 					min_y = max(turf.y, min_y)

yogstation/code/datums/mapgen/JungleGen.dm

@@ -248,17 +248,13 @@
 		var/datum/biome/jungleland/selected_biome = possible_biomes[toxic_pick][humid_pick]
 
 		selected_biome = SSmapping.biomes[selected_biome] //Get the instance of this biome from SSmapping
-		var/turf/GT = selected_biome.generate_turf(gen_turf,density_strings)
-		if(istype(GT,/turf/open/floor/plating/dirt/jungleland))
-			var/turf/open/floor/plating/dirt/jungleland/J = GT
+		var/turf/generated_terrain = selected_biome.generate_turf(gen_turf,density_strings)
+		if(istype(generated_terrain,/turf/open/floor/plating/dirt/jungleland))
+			var/turf/open/floor/plating/dirt/jungleland/J = generated_terrain
 			J.ore_present = ore_map[world.maxx * (gen_turf.y - 1) + gen_turf.x]
 		var/area/jungleland/jungle_area = selected_biome.this_area 
-		var/area/old_area = GT.loc
-		old_area.contents -= GT 
-		old_area.contained_turfs -= GT
-		jungle_area.contents += GT
-		jungle_area.contained_turfs += GT
-		GT.change_area(old_area,jungle_area)
+		var/area/old_area = generated_terrain.loc
+		generated_terrain.change_area(old_area, jungle_area)
 		CHECK_TICK
 
 	for(var/biome in subtypesof(/datum/biome/jungleland))

yogstation/code/game/gamemodes/battle_royale/battleroyale.dm

@@ -271,7 +271,7 @@ GLOBAL_VAR(final_zone)
 			continue //also, ideally keeps people out of maints, and in larger open areas that are more interesting
 		if(is_type_in_list(lootlake, weathered))
 			continue //if the area is covered with a storm, don't spawn loot (less lag)
-		var/number = LAZYLEN(lootlake.get_contained_turfs())//so bigger areas spawn more crates
+		var/number = LAZYLEN(lootlake.get_zlevel_turf_lists())//so bigger areas spawn more crates
 		var/amount = round(number / ROOMSIZESCALING) + prob(((number % ROOMSIZESCALING)/ROOMSIZESCALING)*100) //any remaining tiles gives a probability to have an extra crate
 		for(var/I = 0, I < amount, I++)
 			var/turf/turfy = pick(get_area_turfs(lootlake))