diff --git a/code/datums/diseases/advance/advance.dm b/code/datums/diseases/advance/advance.dm
index dcfa0f13187..c4084dd18ee 100644
--- a/code/datums/diseases/advance/advance.dm
+++ b/code/datums/diseases/advance/advance.dm
@@ -32,7 +32,7 @@
 	var/list/symptoms = list() // The symptoms of the disease.
 	var/id = ""
 	var/processing = 0
-	
+
 	// The order goes from easy to cure to hard to cure.
 	var/static/list/advance_cures = 	list(
 									"sodiumchloride", "sugar", "orangejuice",
@@ -399,7 +399,7 @@
 			AD.Refresh()
 
 		for(var/mob/living/carbon/human/H in shuffle(GLOB.living_mob_list))
-			if(H.z != 1)
+			if(H.z != ZLEVEL_STATION)
 				continue
 			if(!H.HasDisease(D))
 				H.ForceContractDisease(D)
diff --git a/code/game/gamemodes/antag_spawner.dm b/code/game/gamemodes/antag_spawner.dm
index 3c8b83203f3..e1cbd922bdf 100644
--- a/code/game/gamemodes/antag_spawner.dm
+++ b/code/game/gamemodes/antag_spawner.dm
@@ -237,7 +237,7 @@
 
 
 /obj/item/weapon/antag_spawner/slaughter_demon/attack_self(mob/user)
-	if(user.z != 1)
+	if(user.z != ZLEVEL_STATION)
 		to_chat(user, "<span class='notice'>You should probably wait until you reach the station.</span>")
 		return
 	if(used)
diff --git a/code/game/gamemodes/game_mode.dm b/code/game/gamemodes/game_mode.dm
index 348526abdec..50169104365 100644
--- a/code/game/gamemodes/game_mode.dm
+++ b/code/game/gamemodes/game_mode.dm
@@ -233,11 +233,11 @@
 			if(ishuman(M))
 				if(!M.stat)
 					surviving_humans++
-					if(M.z == 2)
+					if(M.z == ZLEVEL_CENTCOM)
 						escaped_humans++
 			if(!M.stat)
 				surviving_total++
-				if(M.z == 2)
+				if(M.z == ZLEVEL_CENTCOM)
 					escaped_total++
 
 
diff --git a/code/game/gamemodes/gang/gang_items.dm b/code/game/gamemodes/gang/gang_items.dm
index a9607639c05..12d833f3623 100644
--- a/code/game/gamemodes/gang/gang_items.dm
+++ b/code/game/gamemodes/gang/gang_items.dm
@@ -325,13 +325,13 @@
 		user.put_in_hands(O)
 	if(spawn_msg)
 		to_chat(user, spawn_msg)
-		
+
 /datum/gang_item/equipment/wetwork_boots
 	name = "Wetwork boots"
 	id = "wetwork"
 	cost = 20
 	item_path = /obj/item/clothing/shoes/combat/gang
-	
+
 /obj/item/clothing/shoes/combat/gang
 	name = "Wetwork boots"
 	desc = "A gang's best hitmen are prepared for anything."
@@ -412,7 +412,7 @@
 /datum/gang_item/equipment/dominator/purchase(mob/living/carbon/user, datum/gang/gang, obj/item/device/gangtool/gangtool)
 	var/area/usrarea = get_area(user.loc)
 	var/usrturf = get_turf(user.loc)
-	if(initial(usrarea.name) == "Space" || isspaceturf(usrturf) || usr.z != 1)
+	if(initial(usrarea.name) == "Space" || isspaceturf(usrturf) || usr.z != ZLEVEL_STATION)
 		to_chat(user, "<span class='warning'>You can only use this on the station!</span>")
 		return FALSE
 
diff --git a/code/game/gamemodes/gang/recaller.dm b/code/game/gamemodes/gang/recaller.dm
index 3e4debd9749..8363261c5d3 100644
--- a/code/game/gamemodes/gang/recaller.dm
+++ b/code/game/gamemodes/gang/recaller.dm
@@ -197,7 +197,7 @@
 		return 0
 
 	var/turf/userturf = get_turf(user)
-	if(userturf.z != 1) //Shuttle can only be recalled while on station
+	if(userturf.z != ZLEVEL_STATION) //Shuttle can only be recalled while on station
 		to_chat(user, "<span class='warning'>\icon[src]Error: Device out of range of station communication arrays.</span>")
 		recalling = 0
 		return 0
@@ -215,7 +215,7 @@
 	log_game("[key_name(user)] has tried to recall the shuttle with a gangtool.")
 	message_admins("[key_name_admin(user)] has tried to recall the shuttle with a gangtool.", 1)
 	userturf = get_turf(user)
-	if(userturf.z == 1) //Check one more time that they are on station.
+	if(userturf.z == ZLEVEL_STATION) //Check one more time that they are on station.
 		if(SSshuttle.cancelEvac(user))
 			gang.recalls -= 1
 			return 1
diff --git a/code/modules/admin/admin.dm b/code/modules/admin/admin.dm
index 3371914bb83..7f47d30a955 100644
--- a/code/modules/admin/admin.dm
+++ b/code/modules/admin/admin.dm
@@ -432,7 +432,7 @@
 			if("Hard Restart (No Delay, No Feeback Reason)")
 				world.Reboot()
 			if("Hardest Restart (No actions, just reboot)")
-				world.Reboot(fast_track = TRUE)		
+				world.Reboot(fast_track = TRUE)
 
 /datum/admins/proc/end_round()
 	set category = "Server"
@@ -609,7 +609,7 @@
 		if(3)
 			var/count = 0
 			for(var/mob/living/carbon/monkey/Monkey in world)
-				if(Monkey.z == 1)
+				if(Monkey.z == ZLEVEL_STATION)
 					count++
 			return "Kill all [count] of the monkeys on the station"
 		if(4)
diff --git a/code/modules/events/brand_intelligence.dm b/code/modules/events/brand_intelligence.dm
index cd477d736ff..d655337ba68 100644
--- a/code/modules/events/brand_intelligence.dm
+++ b/code/modules/events/brand_intelligence.dm
@@ -27,7 +27,7 @@
 
 /datum/round_event/brand_intelligence/start()
 	for(var/obj/machinery/vending/V in GLOB.machines)
-		if(V.z != 1)
+		if(V.z != ZLEVEL_STATION)
 			continue
 		vendingMachines.Add(V)
 	if(!vendingMachines.len)
diff --git a/code/modules/events/disease_outbreak.dm b/code/modules/events/disease_outbreak.dm
index 1d870b7f655..123170fec59 100644
--- a/code/modules/events/disease_outbreak.dm
+++ b/code/modules/events/disease_outbreak.dm
@@ -25,7 +25,7 @@
 		var/turf/T = get_turf(H)
 		if(!T)
 			continue
-		if(T.z != 1)
+		if(T.z != ZLEVEL_STATION)
 			continue
 		var/foundAlready = 0	// don't infect someone that already has the virus
 		for(var/datum/disease/D in H.viruses)
diff --git a/code/modules/events/holiday/xmas.dm b/code/modules/events/holiday/xmas.dm
index e29888f888d..c1139d4aa8d 100644
--- a/code/modules/events/holiday/xmas.dm
+++ b/code/modules/events/holiday/xmas.dm
@@ -25,7 +25,7 @@
 
 /datum/round_event/presents/start()
 	for(var/obj/structure/flora/tree/pine/xmas in world)
-		if(xmas.z != 1)
+		if(xmas.z != ZLEVEL_STATION)
 			continue
 		for(var/turf/open/floor/T in orange(1,xmas))
 			for(var/i=1,i<=rand(1,5),i++)
diff --git a/code/modules/events/wizard/curseditems.dm b/code/modules/events/wizard/curseditems.dm
index 2d0b5251d50..d8e95b5bb53 100644
--- a/code/modules/events/wizard/curseditems.dm
+++ b/code/modules/events/wizard/curseditems.dm
@@ -38,7 +38,7 @@
 			ruins_wizard_loadout = 1
 
 	for(var/mob/living/carbon/human/H in GLOB.living_mob_list)
-		if(ruins_spaceworthiness && (H.z != 1 || isspaceturf(H.loc) || isplasmaman(H)))
+		if(ruins_spaceworthiness && (H.z != ZLEVEL_STATION || isspaceturf(H.loc) || isplasmaman(H)))
 			continue	//#savetheminers
 		if(ruins_wizard_loadout && H.mind && ((H.mind in SSticker.mode.wizards) || (H.mind in SSticker.mode.apprentices)))
 			continue
diff --git a/code/modules/events/wizard/shuffle.dm b/code/modules/events/wizard/shuffle.dm
index b6fe96ba976..e04cb2da2bd 100644
--- a/code/modules/events/wizard/shuffle.dm
+++ b/code/modules/events/wizard/shuffle.dm
@@ -13,7 +13,7 @@
 	var/list/mobs	 = list()
 
 	for(var/mob/living/carbon/human/H in GLOB.living_mob_list)
-		if(H.z != 1)
+		if(H.z != ZLEVEL_STATION)
 			continue //lets not try to strand people in space or stuck in the wizards den
 		moblocs += H.loc
 		mobs += H
diff --git a/code/modules/power/apc.dm b/code/modules/power/apc.dm
index 6c6a088644a..e58240b0452 100644
--- a/code/modules/power/apc.dm
+++ b/code/modules/power/apc.dm
@@ -828,7 +828,7 @@
 	if(!malf.can_shunt)
 		to_chat(malf, "<span class='warning'>You cannot shunt!</span>")
 		return
-	if(src.z != 1)
+	if(src.z != ZLEVEL_STATION)
 		return
 	occupier = new /mob/living/silicon/ai(src, malf.laws, malf) //DEAR GOD WHY?	//IKR????
 	occupier.adjustOxyLoss(malf.getOxyLoss())