Merge pull request #11332 from PsiOmegaDelta/151019-BloodUponBlood

Limits the number of runes to one per turf.

code/game/gamemodes/cult/ritual.dm

@@ -527,7 +527,11 @@ var/global/list/rnwords = list("ire","ego","nahlizet","certum","veri","jatkaa","
 				user << "\red You do not have enough space to write a proper rune."
 			var/list/runes = list("teleport", "itemport", "tome", "armor", "convert", "tear in reality", "emp", "drain", "seer", "raise", "obscure", "reveal", "astral journey", "manifest", "imbue talisman", "sacrifice", "wall", "freedom", "cultsummon", "deafen", "blind", "bloodboil", "communicate", "stun")
 			r = input("Choose a rune to scribe", "Rune Scribing") in runes //not cancellable.
-			var/obj/effect/rune/R = new /obj/effect/rune
+			if(locate(/obj/effect/rune) in user.loc)
+				user << "<span class='warning'>There is already a rune in this location.</span>"
+				return
+
+			var/obj/effect/rune/R = new /obj/effect/rune(user.loc)
 			if(istype(user, /mob/living/carbon/human))
 				var/mob/living/carbon/human/H = user
 				R.blood_DNA = list()

code/modules/spells/general/rune_write.dm

@@ -21,6 +21,10 @@
 		runerandom()
 	var/list/runes = list("Teleport", "Teleport Other", "Spawn a Tome", "Change Construct Type", "Convert", "EMP", "Drain Blood", "See Invisible", "Resurrect", "Hide Runes", "Reveal Runes", "Astral Journey", "Manifest a Ghost", "Imbue Talisman", "Sacrifice", "Wall", "Free Cultist", "Summon Cultist", "Deafen", "Blind", "BloodBoil", "Communicate", "Stun")
 	var/r = input(user, "Choose a rune to scribe", "Rune Scribing") in runes //not cancellable.
+	if(locate(/obj/effect/rune) in user.loc)
+		user << "<span class='warning'>There is already a rune in this location.</span>"
+		return
+
 	var/obj/effect/rune/R = new /obj/effect/rune(user.loc)
 	if(istype(user.loc,/turf))
 		var/area/A = get_area(user)