Adds ability to write on walls with blood

code/game/objects/effects/decals/Cleanable/humans.dm

@@ -70,10 +70,45 @@
 	spawn(DRYING_TIME)
 		Del()
 
+/obj/effect/decal/cleanable/blood/attack_hand(mob/living/carbon/human/user)
+	..()
+	if (amount && istype(user))
+		add_fingerprint(user)
+		if (user.gloves)
+			return
+		var/taken = rand(1,amount)
+		amount -= taken
+		user << "<span class='notice'>You get some blood on your hands.</span>"
+		if (!user.blood_DNA)
+			user.blood_DNA = list()
+		user.blood_DNA |= blood_DNA.Copy()
+		user.bloody_hands += taken
+		user.update_inv_gloves(1)
+		user.verbs += /mob/living/carbon/human/proc/bloody_doodle
+
 /obj/effect/decal/cleanable/blood/splatter
 	random_icon_states = list("gibbl1", "gibbl2", "gibbl3", "gibbl4", "gibbl5")
 	amount = 2
 
+/obj/effect/decal/cleanable/blood/writing
+	icon_state = "tracks"
+	desc = "It looks like a writing in blood."
+	gender = NEUTER
+	random_icon_states = list("writing1","writing2","writing3","writing4","writing5")
+	amount = 0
+	var/message
+
+/obj/effect/decal/cleanable/blood/writing/New()
+	..()
+	for(var/obj/effect/decal/cleanable/blood/writing/W in loc)
+		random_icon_states.Remove(W.icon_state)
+	icon_state = pick(random_icon_states)
+
+/obj/effect/decal/cleanable/blood/writing/examine()
+	..()
+	usr << "It reads: <font color='#600000'>\"[message]\"<font>"
+
+
 /obj/effect/decal/cleanable/blood/green
 	name = "green blood"
 	desc = "It's green and gooey. Perhaps it's the chef's cooking?"

code/modules/mob/living/carbon/human/human.dm

@@ -1186,6 +1186,7 @@
 		src.update_inv_gloves(1,1)	//handles bloody hands overlays and updating
 	else
 		src.update_inv_gloves(1,0)
+	verbs += /mob/living/carbon/human/proc/bloody_doodle
 	return 1 //we applied blood to the item
 
 /mob/living/carbon/human/clean_blood()
@@ -1363,3 +1364,54 @@ mob/living/carbon/human/yank_out_object()
 		return 1
 	else
 		return 0
+
+
+/mob/living/carbon/human/proc/bloody_doodle()
+	set category = "IC"
+	set name = "Write in blood"
+	set desc = "Use blood on your hands to write a short message on the floor or a wall, murder mystery style."
+
+	if (usr != src)
+		return 0 //something is terribly wrong
+
+	if (!bloody_hands)
+		verbs -= /mob/living/carbon/human/proc/bloody_doodle
+
+	if (src.gloves)
+		src << "<span class='warning'>Your [src.gloves] are getting in the way.</span>"
+		return
+
+	var/turf/simulated/T = src.loc
+	if (!istype(T)) //to prevent doodling out of mechs and lockers
+		src << "<span class='warning'>You cannot reach the floor.</span>"
+		return
+
+	var/direction = input(src,"Which way?","Tile selection") as anything in list("Here","North","South","East","West")
+	if (direction != "Here")
+		T = get_step(T,text2dir(direction))
+	if (!istype(T))
+		src << "<span class='warning'>You cannot doodle there.</span>"
+		return
+
+	var/num_doodles = 0
+	for (var/obj/effect/decal/cleanable/blood/writing/W in T)
+		num_doodles++
+	if (num_doodles > 4)
+		src << "<span class='warning'>There is no space to write on!</span>"
+		return
+
+	var/max_length = bloody_hands * 30 //tweeter style
+
+	var/message = stripped_input(src,"Write a message. It cannot be longer than [max_length] characters.","Blood writing", "")
+
+	if (message)
+		var/used_blood_amount = round(length(message) / 30, 1)
+		bloody_hands = max(0, bloody_hands - used_blood_amount) //use up some blood
+
+		if (length(message) > max_length)
+			message += "-"
+			src << "<span class='warning'>You ran out of blood to write with!</span>"
+
+		var/obj/effect/decal/cleanable/blood/writing/W = new(T)
+		W.message = message
+		W.add_fingerprint(src)