On primary antagonist rounds (wizard/blob/malfunction) if the config is set for continous rounds the round will convert on the fly to a new mode choosen from these mode if the primary antagonist dies:

EXTENDED
TRAITOR
CHANGELING
DOUBLE AGENTS
TRAITORLING

based on the game probabilities set through the config.

The round will not convert if more than 30% of the players are dead (round immediatly ends) or if the shuttle is beyond the point of no return (the round ends normally).

Adds the CONTINIOUS_ROUND_BLOB config

code/controllers/configuration.dm

@@ -90,6 +90,7 @@
 	var/continuous_round_rev = 0		// Gamemodes which end instantly will instead keep on going until the round ends by escape shuttle or nuke.
 	var/continuous_round_wiz = 0
 	var/continuous_round_malf = 0
+	var/continuous_round_blob = 0
 	var/shuttle_refuel_delay = 12000
 	var/show_game_type_odds = 0			//if set this allows players to see the odds of each roundtype on the get revision screen
 	var/mutant_races = 0				//players can choose their mutant race before joining the game
@@ -361,6 +362,8 @@
 					config.continuous_round_wiz		= 1
 				if("continuous_round_malf")
 					config.continuous_round_malf	= 1
+				if("continuous_round_blob")
+					config.continuous_round_blob	= 1
 				if("shuttle_refuel_delay")
 					config.shuttle_refuel_delay     = text2num(value)
 				if("show_game_type_odds")

code/game/gamemodes/blob/blob_finish.dm

@@ -1,9 +1,21 @@
 /datum/game_mode/blob/check_finished()
+	if(round_converted)
+		return 0
 	if(infected_crew.len > burst)//Some blobs have yet to burst
 		return 0
 	if(blobwincount <= blobs.len)//Blob took over
 		return 1
 	if(!blob_cores.len) // blob is dead
+		if(config.continuous_round_blob)
+			if(!convert_roundtype())
+				return ..()
+			else
+				if(SSshuttle.emergency.mode == SHUTTLE_STRANDED)
+					SSshuttle.emergency.mode = SHUTTLE_DOCKED
+					SSshuttle.emergency.timer = world.time
+					priority_announce("Hostile enviroment resolved. You have 3 minutes to board the Emergency Shuttle.", null, 'sound/AI/shuttledock.ogg', "Priority")
+				round_converted = 1
+				return 0
 		return 1
 	if(station_was_nuked)//Nuke went off
 		return 1

code/game/gamemodes/changeling/changeling.dm

@@ -13,6 +13,7 @@ var/list/possible_changeling_IDs = list("Alpha","Beta","Gamma","Delta","Epsilon"
 	required_players = 15
 	required_enemies = 1
 	recommended_enemies = 4
+	reroll_friendly = 1
 
 
 	var/const/prob_int_murder_target = 50 // intercept names the assassination target half the time

code/game/gamemodes/extended/extended.dm

@@ -2,6 +2,7 @@
 	name = "extended"
 	config_tag = "extended"
 	required_players = 0
+	reroll_friendly = 1
 
 /datum/game_mode/announce()
 	world << "<B>The current game mode is - Extended Role-Playing!</B>"

code/game/gamemodes/game_mode.dm

@@ -29,6 +29,8 @@
 	var/pre_setup_before_jobs = 0
 	var/antag_flag = null //preferences flag such as BE_WIZARD that need to be turned on for players to be antag
 	var/datum/mind/sacrifice_target = null
+	var/round_converted = 0
+	var/reroll_friendly 	//During mode conversion only these are in the running
 
 	var/const/waittime_l = 600
 	var/const/waittime_h = 1800 // started at 1800
@@ -88,6 +90,50 @@
 /datum/game_mode/proc/make_antag_chance(var/mob/living/carbon/human/character)
 	return
 
+///convert_roundtype()
+///Allows rounds to basically be "rerolled" should the initial premise fall through
+/datum/game_mode/proc/convert_roundtype()
+	var/list/datum/game_mode/runnable_modes = config.get_runnable_modes()
+	for(var/datum/game_mode/G in runnable_modes)
+		if(!G.reroll_friendly)	del(G)
+
+	if(!runnable_modes)	return 0
+
+	var/list/datum/game_mode/replacementmode = pickweight(runnable_modes)
+
+	switch(SSshuttle.emergency.mode) //Rounds on the verge of ending don't get new antags, they just run out
+		if(SHUTTLE_STRANDED, SHUTTLE_ESCAPE)
+			return 1
+		if(SHUTTLE_CALL)
+			if(SSshuttle.emergency.timeLeft(1) < initial(SSshuttle.emergencyCallTime)*0.5)
+				return 1
+
+	var/list/living_crew = list()
+
+	for(var/mob in player_list)
+		if(mob in living_mob_list)
+			living_crew += mob
+	if(living_crew.len / player_list.len <= 0.7) //If a lot of the player base died, we start fresh
+		return 0
+
+	var/list/antag_canadates = list()
+
+	for(var/mob/living/carbon/human/H in living_crew)
+		antag_canadates += H
+
+	if(!antag_canadates)	return 1
+
+	antag_canadates = shuffle(antag_canadates)
+
+	if(config.protect_roles_from_antagonist)
+		replacementmode.restricted_jobs += replacementmode.protected_jobs
+	if(config.protect_assistant_from_antagonist)
+		replacementmode.restricted_jobs += "Assistant"
+	for(var/mob/living/carbon/human/H in antag_canadates)
+		replacementmode.make_antag_chance(H)
+
+	return 1
+
 ///process()
 ///Called by the gameticker
 /datum/game_mode/proc/process()

code/game/gamemodes/malfunction/malfunction.dm

@@ -153,6 +153,8 @@
 				priority_announce("Hostile enviroment resolved. You have 3 minutes to board the Emergency Shuttle.", null, 'sound/AI/shuttledock.ogg', "Priority")
 			SSshuttle.emergencyNoEscape = 0
 			malf_mode_declared = 0
+			convert_roundtype()
+			round_converted = 1
 		else
 			return 1
 	return ..() //check for shuttle and nuke

code/game/gamemodes/traitor/traitor.dm

@@ -15,6 +15,7 @@
 	required_players = 0
 	required_enemies = 1
 	recommended_enemies = 4
+	reroll_friendly = 1
 
 	var/traitors_possible = 4 //hard limit on traitors if scaling is turned off
 	var/num_modifier = 0 // Used for gamemodes, that are a child of traitor, that need more than the usual.

code/game/gamemodes/wizard/wizard.dm

@@ -170,7 +170,7 @@
 
 /datum/game_mode/wizard/check_finished()
 
-	if(config.continuous_round_wiz)
+	if(round_converted)
 		return ..()
 
 	var/wizards_alive = 0
@@ -192,11 +192,17 @@
 
 	if (wizards_alive || traitors_alive)
 		return ..()
-	else
-		finished = 1
-		return 1
 
+	if(config.continuous_round_wiz)
+		if(!convert_roundtype())
+			finished = 1
+			return 1
+		else
+			round_converted = 1
+			return ..()
 
+	finished = 1
+	return 1
 
 /datum/game_mode/wizard/declare_completion()
 	if(finished)

config/game_options.txt

@@ -102,6 +102,7 @@ PROBABILITY SANDBOX 0
 #CONTINUOUS_ROUND_REV
 #CONTINUOUS_ROUND_WIZ
 #CONTINUOUS_ROUND_MALF
+#CONTINUOUS_ROUND_BLOB
 
 ## The amount of time it takes for the emergency shuttle to be called, from round start.
 SHUTTLE_REFUEL_DELAY 12000