diff --git a/code/__DEFINES/subsystems.dm b/code/__DEFINES/subsystems.dm
index 9ec26b7506..247e1109f8 100644
--- a/code/__DEFINES/subsystems.dm
+++ b/code/__DEFINES/subsystems.dm
@@ -46,8 +46,8 @@
 #define INIT_ORDER_DBCORE 18
 #define INIT_ORDER_BLACKBOX 17
 #define INIT_ORDER_SERVER_MAINT 16
-#define INIT_ORDER_JOBS 15
-#define INIT_ORDER_EVENTS 14
+#define INIT_ORDER_EVENTS 15
+#define INIT_ORDER_JOBS 14
 #define INIT_ORDER_TICKER 13
 #define INIT_ORDER_MAPPING 12
 #define INIT_ORDER_ATOMS 11
diff --git a/code/controllers/configuration/entries/game_options.dm b/code/controllers/configuration/entries/game_options.dm
index f2c9cd3315..a49742e6b0 100644
--- a/code/controllers/configuration/entries/game_options.dm
+++ b/code/controllers/configuration/entries/game_options.dm
@@ -112,27 +112,7 @@ CONFIG_DEF(flag/show_game_type_odds)	//if set this allows players to see the odd
 
 CONFIG_DEF(flag/join_with_mutant_race)	//players can choose their mutant race before joining the game
 
-CONFIG_DEF(keyed_flag_list/roundstart_races)	//races you can play as from the get go. If left undefined the game's roundstart var for species is used
-	var/first_edit = TRUE
-
-/datum/config_entry/keyed_flag_list/roundstart_races/New()
-	for(var/I in subtypesof(/datum/species))
-		var/datum/species/S = I
-		if(initial(S.roundstart))
-			value[initial(S.id)] = TRUE
-	..()
-
-/datum/config_entry/keyed_flag_list/roundstart_races/ValidateAndSet(str_val)
-	var/list/old_val
-	if(first_edit)
-		old_val = value
-		old_val = old_val.Copy()
-	. = ..()
-	if(first_edit)
-		if(!.)
-			value = old_val
-		else
-			first_edit = FALSE
+CONFIG_DEF(keyed_flag_list/roundstart_races)	//races you can play as from the get go.
 
 CONFIG_DEF(flag/join_with_mutant_humans)	//players can pick mutant bodyparts for humans before joining the game
 
@@ -188,7 +168,7 @@ CONFIG_DEF(number/run_delay)	//Used for modifying movement speed for mobs.
 
 CONFIG_DEF(number/walk_delay)
 
-	
+
 CONFIG_DEF(number/human_delay)	//Mob specific modifiers. NOTE: These will affect different mob types in different ways
 CONFIG_DEF(number/robot_delay)
 CONFIG_DEF(number/monkey_delay)
diff --git a/code/controllers/subsystem/job.dm b/code/controllers/subsystem/job.dm
index fa6ca7e26b..5645f0527f 100644
--- a/code/controllers/subsystem/job.dm
+++ b/code/controllers/subsystem/job.dm
@@ -18,6 +18,7 @@ SUBSYSTEM_DEF(job)
 		SetupOccupations()
 	if(CONFIG_GET(flag/load_jobs_from_txt))
 		LoadJobs()
+	generate_selectable_species()
 	..()
 
 
diff --git a/code/controllers/subsystem/ticker.dm b/code/controllers/subsystem/ticker.dm
index 4b198d1e80..e1828b737a 100755
--- a/code/controllers/subsystem/ticker.dm
+++ b/code/controllers/subsystem/ticker.dm
@@ -12,7 +12,7 @@ SUBSYSTEM_DEF(ticker)
 	var/force_ending = 0					//Round was ended by admin intervention
 	// If true, there is no lobby phase, the game starts immediately.
 	var/start_immediately = FALSE
-	var/setup_done = FALSE //All game setup done including mode post setup and 
+	var/setup_done = FALSE //All game setup done including mode post setup and
 
 	var/hide_mode = 0
 	var/datum/game_mode/mode = null
@@ -127,7 +127,7 @@ SUBSYSTEM_DEF(ticker)
 		login_music = pick(music)
 	else
 		login_music = "config/title_music/sounds/[pick(music)]"
-	
+
 
 	crewobjlist = typesof(/datum/objective/crew)
 	miscreantobjlist = (typesof(/datum/objective/miscreant) - /datum/objective/miscreant)
@@ -141,6 +141,7 @@ SUBSYSTEM_DEF(ticker)
 		GLOB.syndicate_code_phrase	= generate_code_phrase()
 	if(!GLOB.syndicate_code_response)
 		GLOB.syndicate_code_response = generate_code_phrase()
+
 	..()
 	start_at = world.time + (CONFIG_GET(number/lobby_countdown) * 10)
 
diff --git a/code/datums/dna.dm b/code/datums/dna.dm
index 12555ee038..3987b49750 100644
--- a/code/datums/dna.dm
+++ b/code/datums/dna.dm
@@ -263,7 +263,7 @@
 /mob/living/carbon/proc/create_dna()
 	dna = new /datum/dna(src)
 	if(!dna.species)
-		var/rando_race = pick(CONFIG_GET(keyed_flag_list/roundstart_races))
+		var/rando_race = pick(GLOB.roundstart_races)
 		dna.species = new rando_race()
 
 //proc used to update the mob's appearance after its dna UI has been changed
diff --git a/code/game/machinery/computer/cloning.dm b/code/game/machinery/computer/cloning.dm
index 31126a6c08..ee316b3eed 100644
--- a/code/game/machinery/computer/cloning.dm
+++ b/code/game/machinery/computer/cloning.dm
@@ -470,7 +470,7 @@
 		// species datums
 		R.fields["mrace"] = dna.species
 	else
-		var/datum/species/rando_race = pick(CONFIG_GET(keyed_flag_list/roundstart_races))
+		var/datum/species/rando_race = pick(GLOB.roundstart_races)
 		R.fields["mrace"] = rando_race.type
 
 	R.fields["ckey"] = mob_occupant.ckey
diff --git a/code/game/machinery/computer/security.dm b/code/game/machinery/computer/security.dm
index 8859522ed2..fba60f34ab 100644
--- a/code/game/machinery/computer/security.dm
+++ b/code/game/machinery/computer/security.dm
@@ -598,7 +598,7 @@ What a mess.*/
 							active1.fields["age"] = t1
 					if("species")
 						if(istype(active1, /datum/data/record))
-							var/t1 = input("Select a species", "Species Selection") as null|anything in CONFIG_GET(keyed_flag_list/roundstart_races)
+							var/t1 = input("Select a species", "Species Selection") as null|anything in GLOB.roundstart_races
 							if(!canUseSecurityRecordsConsole(usr, t1, a1))
 								return
 							active1.fields["species"] = t1
@@ -766,7 +766,7 @@ What a mess.*/
 				if(6)
 					R.fields["m_stat"] = pick("*Insane*", "*Unstable*", "*Watch*", "Stable")
 				if(7)
-					R.fields["species"] = pick(CONFIG_GET(keyed_flag_list/roundstart_races))
+					R.fields["species"] = pick(GLOB.roundstart_races)
 				if(8)
 					var/datum/data/record/G = pick(GLOB.data_core.general)
 					R.fields["photo_front"] = G.fields["photo_front"]
diff --git a/code/game/objects/structures/mirror.dm b/code/game/objects/structures/mirror.dm
index 296e4ba757..711f9baf0b 100644
--- a/code/game/objects/structures/mirror.dm
+++ b/code/game/objects/structures/mirror.dm
@@ -101,8 +101,7 @@
 	..()
 
 /obj/structure/mirror/magic/lesser/New()
-	var/list/L = CONFIG_GET(keyed_flag_list/roundstart_races)
-	choosable_races = L.Copy()
+	choosable_races = GLOB.roundstart_races.Copy()
 	..()
 
 /obj/structure/mirror/magic/badmin/New()
diff --git a/code/modules/client/preferences.dm b/code/modules/client/preferences.dm
index bcbeb55dd2..deaf283418 100644
--- a/code/modules/client/preferences.dm
+++ b/code/modules/client/preferences.dm
@@ -45,7 +45,7 @@ GLOBAL_LIST_EMPTY(preferences_datums)
 	var/allow_midround_antag = 1
 	var/preferred_map = null
 	var/pda_style = MONO
-	
+
 	var/uses_glasses_colour = 0
 
 	var/screenshake = 100
@@ -1187,7 +1187,7 @@ GLOBAL_LIST_EMPTY(preferences_datums)
 
 				if("species")
 
-					var/result = input(user, "Select a species", "Species Selection") as null|anything in CONFIG_GET(keyed_flag_list/roundstart_races)
+					var/result = input(user, "Select a species", "Species Selection") as null|anything in GLOB.roundstart_races
 
 					if(result)
 						var/newtype = GLOB.species_list[result]
diff --git a/code/modules/client/preferences_savefile.dm b/code/modules/client/preferences_savefile.dm
index dddac1e506..404e64e517 100644
--- a/code/modules/client/preferences_savefile.dm
+++ b/code/modules/client/preferences_savefile.dm
@@ -294,12 +294,11 @@ SAVEFILE UPDATING/VERSIONING - 'Simplified', or rather, more coder-friendly ~Car
 	//Species
 	var/species_id
 	S["species"]			>> species_id
-	var/list/roundstart_races = CONFIG_GET(keyed_flag_list/roundstart_races)
-	if(species_id && (species_id in roundstart_races) && CONFIG_GET(flag/join_with_mutant_race))
+	if(species_id && (species_id in GLOB.roundstart_races) && CONFIG_GET(flag/join_with_mutant_race))
 		var/newtype = GLOB.species_list[species_id]
 		pref_species = new newtype()
-	else if (roundstart_races.len)
-		var/rando_race = pick(roundstart_races)
+	else if (GLOB.roundstart_races.len)
+		var/rando_race = pick(GLOB.roundstart_races)
 		if (rando_race)
 			pref_species = new rando_race()
 
diff --git a/code/modules/events/holiday/halloween.dm b/code/modules/events/holiday/halloween.dm
index 5415eab386..db41a84d4f 100644
--- a/code/modules/events/holiday/halloween.dm
+++ b/code/modules/events/holiday/halloween.dm
@@ -11,11 +11,6 @@
 	for(var/mob/living/carbon/human/H in GLOB.mob_list)
 		var/obj/item/storage/backpack/b = locate() in H.contents
 		new /obj/item/storage/spooky(b)
-		if(ishuman(H) || islizard(H))
-			if(prob(50))
-				H.set_species(/datum/species/skeleton)
-			else
-				H.set_species(/datum/species/zombie)
 
 	for(var/mob/living/simple_animal/pet/dog/corgi/Ian/Ian in GLOB.mob_list)
 		Ian.place_on_head(new /obj/item/bedsheet(Ian))
diff --git a/code/modules/mob/dead/new_player/preferences_setup.dm b/code/modules/mob/dead/new_player/preferences_setup.dm
index 831fde141e..42265b0b6a 100644
--- a/code/modules/mob/dead/new_player/preferences_setup.dm
+++ b/code/modules/mob/dead/new_player/preferences_setup.dm
@@ -14,7 +14,7 @@
 	facial_hair_color = hair_color
 	eye_color = random_eye_color()
 	if(!pref_species)
-		var/rando_race = pick(CONFIG_GET(keyed_flag_list/roundstart_races))
+		var/rando_race = pick(GLOB.roundstart_races)
 		pref_species = new rando_race()
 	features = random_features()
 	age = rand(AGE_MIN,AGE_MAX)
diff --git a/code/modules/mob/living/brain/brain.dm b/code/modules/mob/living/brain/brain.dm
index 94ed0129c7..c175acf9d6 100644
--- a/code/modules/mob/living/brain/brain.dm
+++ b/code/modules/mob/living/brain/brain.dm
@@ -19,7 +19,7 @@
 /mob/living/brain/proc/create_dna()
 	stored_dna = new /datum/dna/stored(src)
 	if(!stored_dna.species)
-		var/rando_race = pick(CONFIG_GET(keyed_flag_list/roundstart_races))
+		var/rando_race = pick(GLOB.roundstart_races)
 		stored_dna.species = new rando_race()
 
 /mob/living/brain/Destroy()
diff --git a/code/modules/mob/living/carbon/human/species.dm b/code/modules/mob/living/carbon/human/species.dm
index 7a212d371b..e7f193ec80 100644
--- a/code/modules/mob/living/carbon/human/species.dm
+++ b/code/modules/mob/living/carbon/human/species.dm
@@ -1,5 +1,7 @@
 // This code handles different species in the game.
 
+GLOBAL_LIST_EMPTY(roundstart_races)
+
 #define HEAT_DAMAGE_LEVEL_1 2
 #define HEAT_DAMAGE_LEVEL_2 3
 #define HEAT_DAMAGE_LEVEL_3 8
@@ -12,7 +14,6 @@
 	var/id	// if the game needs to manually check your race to do something not included in a proc here, it will use this
 	var/limbs_id		//this is used if you want to use a different species limb sprites. Mainly used for angels as they look like humans.
 	var/name	// this is the fluff name. these will be left generic (such as 'Lizardperson' for the lizard race) so servers can change them to whatever
-	var/roundstart = 0	// can this mob be chosen at roundstart? (assuming the config option is checked?)
 	var/default_color = "#FFF"	// if alien colors are disabled, this is the color that will be used by that race
 
 	var/sexes = 1		// whether or not the race has sexual characteristics. at the moment this is only 0 for skeletons and shadows
@@ -92,6 +93,20 @@
 	..()
 
 
+/proc/generate_selectable_species()
+	for(var/I in subtypesof(/datum/species))
+		var/datum/species/S = new I
+		if(S.check_roundstart_eligible())
+			GLOB.roundstart_races += S.id
+			qdel(S)
+	if(!GLOB.roundstart_races.len)
+		GLOB.roundstart_races += "human"
+
+/datum/species/proc/check_roundstart_eligible()
+	if(id in (CONFIG_GET(keyed_flag_list/roundstart_races)))
+		return TRUE
+	return FALSE
+
 /datum/species/proc/random_name(gender,unique,lastname)
 	if(unique)
 		return random_unique_name(gender)
@@ -1152,7 +1167,7 @@
 
 	if(radiation > RAD_MOB_VOMIT && prob(RAD_MOB_VOMIT_PROB))
 		H.vomit(10, TRUE)
-	
+
 	if(radiation > RAD_MOB_MUTATE)
 		if(prob(1))
 			to_chat(H, "<span class='danger'>You mutate!</span>")
diff --git a/code/modules/mob/living/carbon/human/species_types/shadowpeople.dm b/code/modules/mob/living/carbon/human/species_types/shadowpeople.dm
index 4347a8331c..fd030fad45 100644
--- a/code/modules/mob/living/carbon/human/species_types/shadowpeople.dm
+++ b/code/modules/mob/living/carbon/human/species_types/shadowpeople.dm
@@ -24,6 +24,10 @@
 		else if (light_amount < SHADOW_SPECIES_LIGHT_THRESHOLD) //heal in the dark
 			H.heal_overall_damage(1,1)
 
+/datum/species/shadow/check_roundstart_eligible()
+	if(SSevents.holidays && SSevents.holidays[HALLOWEEN])
+		return TRUE
+	return ..()
 
 /datum/species/shadow/nightmare
 	name = "Nightmare"
@@ -60,7 +64,8 @@
 			return -1
 	return 0
 
-
+/datum/species/shadow/nightmare/check_roundstart_eligible()
+	return FALSE
 
 //Organs
 
diff --git a/code/modules/mob/living/carbon/human/species_types/skeletons.dm b/code/modules/mob/living/carbon/human/species_types/skeletons.dm
index be03e591aa..e1b17ab5eb 100644
--- a/code/modules/mob/living/carbon/human/species_types/skeletons.dm
+++ b/code/modules/mob/living/carbon/human/species_types/skeletons.dm
@@ -10,4 +10,13 @@
 	mutanttongue = /obj/item/organ/tongue/bone
 	damage_overlay_type = ""//let's not show bloody wounds or burns over bones.
 	disliked_food = NONE
+<<<<<<< HEAD
 	liked_food = NONE
+=======
+	liked_food = GROSS | MEAT | RAW
+
+/datum/species/skeleton/check_roundstart_eligible()
+	if(SSevents.holidays && SSevents.holidays[HALLOWEEN])
+		return TRUE
+	return ..()
+>>>>>>> dcddc79... Allows species to be blocked from ever being roundstart, can now choose your Halloween species (#31877)
diff --git a/code/modules/mob/living/carbon/human/species_types/synths.dm b/code/modules/mob/living/carbon/human/species_types/synths.dm
index 45b4a28bb5..8b21c2a237 100644
--- a/code/modules/mob/living/carbon/human/species_types/synths.dm
+++ b/code/modules/mob/living/carbon/human/species_types/synths.dm
@@ -118,4 +118,4 @@
 		else
 			return ..()
 	else
-		return ..()
+		return ..()
\ No newline at end of file
diff --git a/code/modules/mob/living/carbon/human/species_types/zombies.dm b/code/modules/mob/living/carbon/human/species_types/zombies.dm
index 016a3635ef..bcf49cd556 100644
--- a/code/modules/mob/living/carbon/human/species_types/zombies.dm
+++ b/code/modules/mob/living/carbon/human/species_types/zombies.dm
@@ -14,6 +14,11 @@
 	disliked_food = NONE
 	liked_food = NONE
 
+/datum/species/zombie/check_roundstart_eligible()
+	if(SSevents.holidays && SSevents.holidays[HALLOWEEN])
+		return TRUE
+	return ..()
+
 /datum/species/zombie/infectious
 	name = "Infectious Zombie"
 	id = "memezombies"
@@ -24,6 +29,10 @@
 	mutanteyes = /obj/item/organ/eyes/night_vision/zombie
 	var/regen_cooldown = 0
 
+/datum/species/zombie/infectious/check_roundstart_eligible()
+	return FALSE
+
+
 /datum/species/zombie/infectious/spec_stun(mob/living/carbon/human/H,amount)
 	. = min(2, amount)