next-we-melt-the-memories-that-are

code/controllers/subsystem/acid.dm

@@ -0,0 +1,36 @@
+SUBSYSTEM_DEF(acid)
+	name = "Acid"
+	priority = FIRE_PRIORITY_ACID
+	flags = SS_NO_INIT|SS_BACKGROUND
+	runlevels = RUNLEVEL_GAME | RUNLEVEL_POSTGAME
+
+	var/list/currentrun = list()
+	var/list/processing = list()
+
+/datum/controller/subsystem/acid/stat_entry()
+	..("P:[processing.len]")
+
+
+/datum/controller/subsystem/acid/fire(resumed = 0)
+	if(!resumed)
+		src.currentrun = processing.Copy()
+
+	//cache for sanic speed (lists are references anyways)
+	var/list/currentrun = src.currentrun
+
+	while(currentrun.len)
+		var/obj/O = currentrun[currentrun.len]
+		currentrun.len--
+		if(!O || QDELETED(O))
+			processing -= O
+			if(MC_TICK_CHECK)
+				return
+			continue
+
+		if(O.acid_level && O.acid_processing())
+		else
+			O.cut_overlay(GLOB.acid_overlay, TRUE)
+			processing -= O
+
+		if(MC_TICK_CHECK)
+			return

code/game/atoms.dm

@@ -719,6 +719,14 @@ var/list/blood_splatter_icons = list()
 /atom/proc/singularity_pull()
 	return
 
+/**
+  * Respond to acid being used on our atom
+  *
+  * Default behaviour is to send COMSIG_ATOM_ACID_ACT and return
+  */
+/atom/proc/acid_act(acidpwr, acid_volume)
+	SEND_SIGNAL(src, COMSIG_ATOM_ACID_ACT, acidpwr, acid_volume)
+
 /atom/proc/narsie_act()
 	return
 

code/game/objects/effects/alien_acid.dm

@@ -1,88 +1,92 @@
-/* Alien shit!
- * Contains:
- *		effect/acid
- */
-
-
-/*
- * Acid
- */
 /obj/effect/acid
 	gender = PLURAL
 	name = "acid"
-	desc = "Burbling corrossive stuff."
-	icon = 'icons/effects/effects.dmi'
+	desc = "Burbling corrosive stuff."
 	icon_state = "acid"
-	density = 0
+	density = FALSE
 	opacity = 0
-	anchored = 1
-	unacidable = 1
-	var/atom/target
-	var/ticks = 0
-	var/target_strength = 0
+	anchored = TRUE
+	resistance_flags = FIRE_PROOF | UNACIDABLE | ACID_PROOF
+	layer = ABOVE_NORMAL_TURF_LAYER
+	var/turf/target
 
 
-/obj/effect/acid/New(loc, targ)
-	..(loc)
-	target = targ
+/obj/effect/acid/Initialize(mapload, acid_pwr, acid_amt)
+	. = ..()
+
+	target = get_turf(src)
+
+	if(acid_amt)
+		acid_level = min(acid_amt * acid_pwr, 12000) //capped so the acid effect doesn't last a half hour on the floor.
 
 	//handle APCs and newscasters and stuff nicely
-	pixel_x = target.pixel_x
-	pixel_y = target.pixel_y
+	pixel_x = target.pixel_x + rand(-4,4)
+	pixel_y = target.pixel_y + rand(-4,4)
 
-	if(isturf(target))	//Turfs take twice as long to take down.
-		target_strength = 640
-	else
-		target_strength = 320
-	tick()
+	START_PROCESSING(SSobj, src)
 
 
-/obj/effect/acid/proc/tick()
+/obj/effect/acid/Destroy()
+	STOP_PROCESSING(SSobj, src)
+	target = null
+	return ..()
+
+/obj/effect/acid/process()
+	. = 1
 	if(!target)
 		qdel(src)
+		return 0
 
-	ticks++
+	if(prob(5))
+		playsound(loc, 'sound/items/welder.ogg', 100, TRUE)
 
-	if(ticks >= target_strength)
-		target.visible_message("<span class='warning'>[target] collapses under its own weight into a puddle of goop and undigested debris!</span>")
-
-		if(istype(target, /obj/structure/closet))
-			var/obj/structure/closet/T = target
-			T.dump_contents()
-			qdel(target)
-
-		if(istype(target, /turf/simulated/mineral))
-			var/turf/simulated/mineral/M = target
-			M.ChangeTurf(/turf/simulated/floor/plating/asteroid/airless)
-
-		if(istype(target, /turf/simulated/floor))
-			var/turf/simulated/floor/F = target
-			F.ChangeTurf(F.baseturf)
-
-		if(istype(target, /turf/simulated/wall))
-			var/turf/simulated/wall/W = target
-			W.dismantle_wall(1)
-
-		else
-			qdel(target)
+	for(var/obj/O in target)
+		if(prob(20) && !(resistance_flags & UNACIDABLE))
+			if(O.acid_level < acid_level * 0.3)
+				var/acid_used = min(acid_level * 0.05, 20)
+				O.acid_act(10, acid_used)
+				acid_level = max(0, acid_level - acid_used * 10)
 
+	acid_level = max(acid_level - (5 + 2 * round(sqrt(acid_level))), 0)
+	if(acid_level <= 0)
 		qdel(src)
-		return
+		return 0
 
-	x = target.x
-	y = target.y
-	z = target.z
+/obj/effect/acid/Crossed(AM as mob|obj)
+	if(isliving(AM))
+		var/mob/living/L = AM
+		if(L.flying)
+			return
+		if(L.m_intent != MOVE_INTENT_WALK && prob(40))
+			var/acid_used = min(acid_level * 0.05, 20)
+			if(L.acid_act(10, acid_used, "feet"))
+				acid_level = max(0, acid_level - acid_used * 10)
+				playsound(L, 'sound/weapons/sear.ogg', 50, TRUE)
+				to_chat(L, "<span class='userdanger'>[src] burns you!</span>")
 
-	switch(target_strength - ticks)
-		if(480)
-			visible_message("<span class='warning'>[target] is holding up against the acid!</span>")
-		if(320)
-			visible_message("<span class='warning'>[target] is being melted by the acid!</span>")
-		if(160)
-			visible_message("<span class='warning'>[target] is struggling to withstand the acid!</span>")
-		if(80)
-			visible_message("<span class='warning'>[target] begins to crumble under the acid!</span>")
+//xenomorph corrosive acid
+/obj/effect/acid/alien
+	var/target_strength = 30
 
-	spawn(1)
-		if(src)
-			tick()
+
+/obj/effect/acid/alien/process()
+	. = ..()
+	if(.)
+		if(prob(45))
+			playsound(loc, 'sound/items/welder.ogg', 100, TRUE)
+		target_strength--
+		if(target_strength <= 0)
+			target.visible_message("<span class='warning'>[target] collapses under its own weight into a puddle of goop and undigested debris!</span>")
+			target.acid_melt()
+			qdel(src)
+		else
+
+			switch(target_strength)
+				if(24)
+					visible_message("<span class='warning'>[target] is holding up against the acid!</span>")
+				if(16)
+					visible_message("<span class='warning'>[target] is being melted by the acid!</span>")
+				if(8)
+					visible_message("<span class='warning'>[target] is struggling to withstand the acid!</span>")
+				if(4)
+					visible_message("<span class='warning'>[target] begins to crumble under the acid!</span>")

code/game/objects/effects/decals/remains.dm

@@ -1,6 +1,12 @@
 /obj/effect/decal/remains
 	gender = PLURAL
 
+/obj/effect/decal/remains/acid_act()
+	visible_message("<span class='warning'>[src] dissolve[gender==PLURAL?"":"s"] into a puddle of sizzling goop!</span>")
+	playsound(src, 'sound/items/welder.ogg', 150, TRUE)
+	new /obj/effect/decal/cleanable/greenglow(drop_location())
+	qdel(src)
+
 /obj/effect/decal/remains/human
 	name = "remains"
 	desc = "They look like human remains. They have a strange aura about them."

code/game/objects/effects/effects.dm

@@ -15,6 +15,12 @@
 /obj/effect/attack_hulk(mob/living/carbon/human/user, does_attack_animation = FALSE)
 	return FALSE
 
+/obj/effect/fire_act(datum/gas_mixture/air, exposed_temperature, exposed_volume, global_overlay = TRUE)
+	return
+
+/obj/effect/acid_act()
+	return
+
 /obj/effect/decal
 	plane = FLOOR_PLANE
 	var/no_scoop = FALSE   //if it has this, don't let it be scooped up

code/game/objects/effects/glowshroom.dm

@@ -188,3 +188,10 @@
 /obj/structure/glowshroom/proc/CheckEndurance()
 	if(endurance <= 0)
 		qdel(src)
+
+/obj/structure/glowshroom/acid_act(acidpwr, acid_volume)
+	. = 1
+	visible_message("<span class='danger'>[src] melts away!</span>")
+	var/obj/effect/decal/cleanable/molten_object/I = new (get_turf(src))
+	I.desc = "Looks like this was \an [src] some time ago."
+	qdel(src)

code/game/objects/items.dm

@@ -218,6 +218,15 @@ var/global/image/fire_overlay = image("icon" = 'icons/goonstation/effects/fire.d
 		A.desc += "\nLooks like this used to be \an [name] some time ago."
 		..()
 
+/obj/item/acid_melt()
+	if(!QDELETED(src))
+		var/turf/T = get_turf(src)
+		var/obj/effect/decal/cleanable/molten_object/MO = new(T)
+		MO.pixel_x = rand(-16,16)
+		MO.pixel_y = rand(-16,16)
+		MO.desc = "Looks like this was \an [src] some time ago."
+		..()
+
 /obj/item/afterattack(atom/target, mob/user, proximity, params)
 	SEND_SIGNAL(src, COMSIG_ITEM_AFTERATTACK, target, user, proximity, params)
 	..()
@@ -251,6 +260,15 @@ var/global/image/fire_overlay = image("icon" = 'icons/goonstation/effects/fire.d
 		else
 			extinguish()
 
+	if(acid_level > 20 && !ismob(loc))// so we can still remove the clothes on us that have acid.
+		var/mob/living/carbon/human/H = user
+		if(istype(H))
+			if(!H.gloves || (!(H.gloves.resistance_flags & (UNACIDABLE|ACID_PROOF))))
+				to_chat(user, "<span class='warning'>The acid on [src] burns your hand!</span>")
+				var/obj/item/organ/external/affecting = H.get_organ("[user.hand ? "l" : "r" ]_arm")
+				if(affecting && affecting.receive_damage( 0, 5 ))		// 5 burn damage
+					H.UpdateDamageIcon()
+
 	if(istype(src.loc, /obj/item/storage))
 		//If the item is in a storage item, take it out
 		var/obj/item/storage/S = src.loc
@@ -578,6 +596,7 @@ var/global/image/fire_overlay = image("icon" = 'icons/goonstation/effects/fire.d
 	if(!do_after(user, 40, target = source))
 		return
 	clean_blood()
+	acid_level = 0
 	user.visible_message("<span class='notice'>[user] washes [src] using [source].</span>", \
 						"<span class='notice'>You wash [src] using [source].</span>")
 	return 1

code/game/objects/obj_defense.dm

@@ -158,6 +158,42 @@
 		qdel(src)
 	return 2
 
+///// ACID
+
+GLOBAL_DATUM_INIT(acid_overlay, /mutable_appearance, mutable_appearance('icons/effects/effects.dmi', "acid"))
+
+///the obj's reaction when touched by acid
+/obj/acid_act(acidpwr, acid_volume)
+	if(!(resistance_flags & UNACIDABLE) && acid_volume)
+
+		if(!acid_level)
+			SSacid.processing[src] = src
+			add_overlay(GLOB.acid_overlay, TRUE)
+		var/acid_cap = acidpwr * 300 //so we cannot use huge amounts of weak acids to do as well as strong acids.
+		if(acid_level < acid_cap)
+			acid_level = min(acid_level + acidpwr * acid_volume, acid_cap)
+		return 1
+
+///the proc called by the acid subsystem to process the acid that's on the obj
+/obj/proc/acid_processing()
+	. = 1
+	if(!(resistance_flags & ACID_PROOF))
+		for(var/armour_value in armor)
+			if(armour_value != "acid" && armour_value != "fire")
+				armor[armour_value] = max(armor[armour_value] - round(sqrt(acid_level) * 0.1), 0)
+		if(prob(33))
+			playsound(loc, 'sound/items/welder.ogg', 150, TRUE)
+		take_damage(min(1 + round(sqrt(acid_level) * 0.3), 300), BURN, "acid", 0)
+
+	acid_level = max(acid_level - (5 + 3 * round(sqrt(acid_level))), 0)
+	if(!acid_level)
+		return 0
+
+///called when the obj is destroyed by acid.
+/obj/proc/acid_melt()
+	SSacid.processing -= src
+	deconstruct(FALSE)
+
 //// FIRE
 
 /obj/fire_act(datum/gas_mixture/air, exposed_temperature, exposed_volume, global_overlay = TRUE)
@@ -202,9 +238,11 @@
 /obj/proc/obj_break(damage_flag)
 	return
 
-//what happens when the obj's integrity reaches zero.
+///what happens when the obj's integrity reaches zero.
 /obj/proc/obj_destruction(damage_flag)
-	if(damage_flag == BURN)
+	if(damage_flag == "acid")
+		acid_melt()
+	else if(damage_flag == "fire")
 		burn()
 	else
 		deconstruct(FALSE)

code/game/objects/objs.dm

@@ -2,7 +2,6 @@
 	//var/datum/module/mod		//not used
 	var/origin_tech = null	//Used by R&D to determine what research bonuses it grants.
 	var/crit_fail = 0
-	var/unacidable = 0 //universal "unacidabliness" var, here so you can use it in any obj.
 	animate_movement = 2
 	var/throwforce = 1
 	var/list/attack_verb = list() //Used in attackby() to say how something was attacked "[x] has been [z.attack_verb] by [y] with [z]"
@@ -15,6 +14,7 @@
 	var/obj_integrity	//defaults to max_integrity
 	var/max_integrity = INFINITY
 	var/integrity_failure = 0 //0 if we have no special broken behavior
+	var/acid_level = 0 //how much acid is on that obj
 
 	var/resistance_flags = NONE // INDESTRUCTIBLE
 	var/can_be_hit = TRUE //can this be bludgeoned by items?

code/game/turfs/simulated/floor.dm

@@ -241,5 +241,8 @@ var/list/icons_to_ignore_at_floor_init = list("damaged1","damaged2","damaged3","
 	if(.)
 		ChangeTurf(/turf/simulated/floor/clockwork)
 
+/turf/simulated/floor/acid_melt()
+	ChangeTurf(baseturf)
+
 /turf/simulated/floor/can_have_cabling()
 	return !burnt && !broken

code/game/turfs/simulated/floor/lava.dm

@@ -14,6 +14,9 @@
 /turf/simulated/floor/plating/lava/ex_act()
 	return
 
+/turf/simulated/floor/plating/lava/acid_act(acidpwr, acid_volume)
+	return
+
 /turf/simulated/floor/plating/lava/airless
 	temperature = TCMB
 

code/game/turfs/simulated/floor/plating.dm

@@ -150,6 +150,10 @@
 /turf/simulated/floor/engine/pry_tile(obj/item/C, mob/user, silent = FALSE)
 	return
 
+/turf/simulated/floor/engine/acid_act(acidpwr, acid_volume)
+	acidpwr = min(acidpwr, 50) //we reduce the power so reinf floor never get melted.
+	. = ..()
+
 /turf/simulated/floor/engine/attackby(obj/item/C as obj, mob/user as mob, params)
 	if(!C || !user)
 		return

code/game/turfs/simulated/minerals.dm

@@ -132,6 +132,9 @@
 		if(istype(M.selected,/obj/item/mecha_parts/mecha_equipment/drill))
 			M.selected.action(src)
 
+/turf/simulated/mineral/acid_melt()
+	ChangeTurf(baseturf)
+
 /turf/simulated/mineral/ex_act(severity, target)
 	..()
 	switch(severity)

code/game/turfs/simulated/walls.dm

@@ -446,6 +446,14 @@
 	if(prob(20))
 		ChangeTurf(/turf/simulated/wall/cult)
 
+/turf/simulated/wall/acid_act(acidpwr, acid_volume)
+	if(explosion_block >= 2)
+		acidpwr = min(acidpwr, 50) //we reduce the power so strong walls never get melted.
+	. = ..()
+
+/turf/simulated/wall/acid_melt()
+	dismantle_wall(1)
+
 /turf/simulated/wall/proc/add_dent(denttype, x=rand(-8, 8), y=rand(-8, 8))
 	if(LAZYLEN(dent_decals) >= MAX_DENT_DECALS)
 		return

code/game/turfs/space/space.dm

@@ -25,7 +25,7 @@
 	var/area/A = loc
 	if(!IS_DYNAMIC_LIGHTING(src) && IS_DYNAMIC_LIGHTING(A))
 		add_overlay(/obj/effect/fullbright)
-		
+
 	if (light_power && light_range)
 		update_light()
 
@@ -265,6 +265,9 @@
 		var/turf/T = locate(destination_x, destination_y, destination_z)
 		user.forceMove(T)
 
+/turf/space/acid_act(acidpwr, acid_volume)
+	return 0
+
 /turf/space/get_smooth_underlay_icon(mutable_appearance/underlay_appearance, turf/asking_turf, adjacency_dir)
 	underlay_appearance.icon = 'icons/turf/space.dmi'
 	underlay_appearance.icon_state = SPACE_ICON_STATE

code/game/turfs/turf.dm

@@ -43,7 +43,7 @@
 
 /turf/Initialize(mapload)
 	. = ..()
-	
+
 	var/area/A = loc
 	if(!IS_DYNAMIC_LIGHTING(src) && IS_DYNAMIC_LIGHTING(A))
 		add_overlay(/obj/effect/fullbright)
@@ -206,7 +206,7 @@
 	var/old_baseturf = baseturf
 	var/turf/W = new path(src)
 	W.baseturf = old_baseturf
-	
+
 	if(!defer_change)
 		W.AfterChange(ignore_air)
 	W.blueprint_data = old_blueprint_data
@@ -412,6 +412,27 @@
 
 ////////////////////////////////////////////////////
 
+/turf/acid_act(acidpwr, acid_volume)
+	. = 1
+	var/acid_type = /obj/effect/acid
+	if(acidpwr >= 200) //alien acid power
+		acid_type = /obj/effect/acid/alien
+	var/has_acid_effect = FALSE
+	for(var/obj/O in src)
+		if(intact && O.level == 1) //hidden under the floor
+			continue
+		if(istype(O, acid_type))
+			var/obj/effect/acid/A = O
+			A.acid_level = min(A.level + acid_volume * acidpwr, 12000)//capping acid level to limit power of the acid
+			has_acid_effect = 1
+			continue
+		O.acid_act(acidpwr, acid_volume)
+	if(!has_acid_effect)
+		new acid_type(src, acidpwr, acid_volume)
+
+/turf/proc/acid_melt()
+	return
+
 /turf/handle_fall(mob/faller, forced)
 	faller.lying = pick(90, 270)
 	if(!forced)
@@ -516,5 +537,5 @@
 /turf/AllowDrop()
 	return TRUE
 
-/turf/proc/water_act(volume, temperature, source)	
+/turf/proc/water_act(volume, temperature, source)
  	return FALSE

code/game/turfs/unsimulated.dm

@@ -10,6 +10,9 @@
 /turf/unsimulated/rpd_act()
 	return
 
+/turf/unsimulated/acid_act(acidpwr, acid_volume, acid_id)
+	return 0
+
 /turf/unsimulated/floor/plating/vox
 	icon_state = "plating"
 	name = "plating"

code/modules/crafting/recipes.dm

@@ -184,8 +184,8 @@
 	result = /obj/item/ammo_casing/shotgun/frag12
 	reqs = list(/obj/item/ammo_casing/shotgun/techshell = 1,
 				/datum/reagent/glycerol = 5,
-				/datum/reagent/sacid = 5,
-				/datum/reagent/facid = 5,)
+				/datum/reagent/acid = 5,
+				/datum/reagent/acid/facid = 5,)
 	tools = list(/obj/item/screwdriver)
 	time = 5
 	category = CAT_WEAPONRY

code/modules/mob/living/carbon/alien/alien_defense.dm

@@ -74,3 +74,6 @@ In all, this is a lot like the monkey code. /N
 				adjustCloneLoss(damage)
 			if(STAMINA)
 				adjustStaminaLoss(damage)
+
+/mob/living/carbon/alien/acid_act(acidpwr, acid_volume)
+	return 0//aliens are immune to acid.

code/modules/mob/living/carbon/alien/humanoid/alien_powers.dm

@@ -70,34 +70,20 @@ Doesn't work on other aliens/AI.*/
 	return
 
 
-/mob/living/carbon/alien/humanoid/proc/corrosive_acid(O as obj|turf in oview(1)) //If they right click to corrode, an error will flash if its an invalid target./N
+/mob/living/carbon/alien/humanoid/proc/corrosive_acid(atom/target) //If they right click to corrode, an error will flash if its an invalid target./N
 	set name = "Corrossive Acid (200)"
 	set desc = "Drench an object in acid, destroying it over time."
 	set category = "Alien"
 
 	if(powerc(200))
-		if(O in oview(1))
-			// OBJ CHECK
-			if(isobj(O))
-				var/obj/I = O
-				if(I.unacidable)	//So the aliens don't destroy energy fields/singularies/other aliens/etc with their acid.
-					to_chat(src, "<span class='noticealien'>You cannot dissolve this object.</span>")
-					return
-			// TURF CHECK
-			else if(istype(O, /turf/simulated))
-				var/turf/simulated/T = O
-				if(T.unacidable)
-					to_chat(src, "<span class='noticealien'>You cannot dissolve this object.</span>")
-					return
-			else// Not a type we can acid.
-				return
-
-			adjustPlasma(-200)
-			new /obj/effect/acid(get_turf(O), O)
-			visible_message("<span class='alertalien'>[src] vomits globs of vile stuff all over [O]. It begins to sizzle and melt under the bubbling mess of acid!</span>")
+		if(target in oview(1))
+			if(target.acid_act(200, 100))
+				visible_message("<span class='alertalien'>[src] vomits globs of vile stuff all over [target]. It begins to sizzle and melt under the bubbling mess of acid!</span>")
+				adjustPlasma(-200)
+			else
+				to_chat(src, "<span class='noticealien'>You cannot dissolve this object.</span>")
 		else
-			to_chat(src, "<span class='noticealien'>Target is too far away.</span>")
-	return
+			to_chat(src, "<span class='noticealien'>[target] is too far away.</span>")
 
 /mob/living/carbon/alien/humanoid/proc/neurotoxin() // ok
 	set name = "Spit Neurotoxin (50)"

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

@@ -1171,3 +1171,10 @@ so that different stomachs can handle things in different ways VB*/
 
 	SEND_SIGNAL(src, COMSIG_MOB_UPDATE_SIGHT)
 	sync_lighting_plane_alpha()
+
+/mob/living/carbon/ExtinguishMob()
+	for(var/X in get_equipped_items())
+		var/obj/item/I = X
+		I.acid_level = 0 //washes off the acid on our clothes
+		I.extinguish() //extinguishes our clothes
+	..()

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

@@ -167,6 +167,152 @@ emp_act
 		O.emp_act(severity)
 	..()
 
+/mob/living/carbon/human/acid_act(acidpwr, acid_volume, bodyzone_hit) //todo: update this to utilize check_obscured_slots() //and make sure it's check_obscured_slots(TRUE) to stop aciding through visors etc
+	var/list/damaged = list()
+	var/list/inventory_items_to_kill = list()
+	var/acidity = acidpwr * min(acid_volume * 0.005, 0.1)
+	//HEAD//
+	if(!bodyzone_hit || bodyzone_hit == "head") //only if we didn't specify a zone or if that zone is the head.
+		var/obj/item/clothing/head_clothes = null
+		if(glasses)
+			head_clothes = glasses
+		if(wear_mask)
+			head_clothes = wear_mask
+		if(head)
+			head_clothes = head
+		if(head_clothes)
+			if(!(head_clothes.resistance_flags & UNACIDABLE))
+				head_clothes.acid_act(acidpwr, acid_volume)
+				update_inv_glasses()
+				update_inv_wear_mask()
+				update_inv_head()
+			else
+				to_chat(src, "<span class='notice'>Your [head_clothes.name] protects your head and face from the acid!</span>")
+		else
+			. = get_organ("head")
+			if(.)
+				damaged += .
+			if(l_ear)
+				inventory_items_to_kill += l_ear
+			if(r_ear)
+				inventory_items_to_kill += r_ear
+
+	//CHEST//
+	if(!bodyzone_hit || bodyzone_hit == "chest")
+		var/obj/item/clothing/chest_clothes = null
+		if(w_uniform)
+			chest_clothes = w_uniform
+		if(wear_suit)
+			chest_clothes = wear_suit
+		if(chest_clothes)
+			if(!(chest_clothes.resistance_flags & UNACIDABLE))
+				chest_clothes.acid_act(acidpwr, acid_volume)
+				update_inv_w_uniform()
+				update_inv_wear_suit()
+			else
+				to_chat(src, "<span class='notice'>Your [chest_clothes.name] protects your body from the acid!</span>")
+		else
+			. = get_organ("chest")
+			if(.)
+				damaged += .
+			if(wear_id)
+				inventory_items_to_kill += wear_id
+			if(wear_pda)
+				inventory_items_to_kill += wear_pda
+			if(r_store)
+				inventory_items_to_kill += r_store
+			if(l_store)
+				inventory_items_to_kill += l_store
+			if(s_store)
+				inventory_items_to_kill += s_store
+
+
+	//ARMS & HANDS//
+	if(!bodyzone_hit || bodyzone_hit == "l_arm" || bodyzone_hit == "r_arm")
+		var/obj/item/clothing/arm_clothes = null
+		if(gloves)
+			arm_clothes = gloves
+		if(w_uniform && ((w_uniform.body_parts_covered & HANDS) || (w_uniform.body_parts_covered & ARMS)))
+			arm_clothes = w_uniform
+		if(wear_suit && ((wear_suit.body_parts_covered & HANDS) || (wear_suit.body_parts_covered & ARMS)))
+			arm_clothes = wear_suit
+
+		if(arm_clothes)
+			if(!(arm_clothes.resistance_flags & UNACIDABLE))
+				arm_clothes.acid_act(acidpwr, acid_volume)
+				update_inv_gloves()
+				update_inv_w_uniform()
+				update_inv_wear_suit()
+			else
+				to_chat(src, "<span class='notice'>Your [arm_clothes.name] protects your arms and hands from the acid!</span>")
+		else
+			. = get_organ("r_arm")
+			if(.)
+				damaged += .
+			. = get_organ("l_arm")
+			if(.)
+				damaged += .
+
+
+	//LEGS & FEET//
+	if(!bodyzone_hit || bodyzone_hit == "l_leg" || bodyzone_hit =="r_leg" || bodyzone_hit == "feet")
+		var/obj/item/clothing/leg_clothes = null
+		if(shoes)
+			leg_clothes = shoes
+		if(w_uniform && ((w_uniform.body_parts_covered & FEET) || (bodyzone_hit != "feet" && (w_uniform.body_parts_covered & LEGS))))
+			leg_clothes = w_uniform
+		if(wear_suit && ((wear_suit.body_parts_covered & FEET) || (bodyzone_hit != "feet" && (wear_suit.body_parts_covered & LEGS))))
+			leg_clothes = wear_suit
+		if(leg_clothes)
+			if(!(leg_clothes.resistance_flags & UNACIDABLE))
+				leg_clothes.acid_act(acidpwr, acid_volume)
+				update_inv_shoes()
+				update_inv_w_uniform()
+				update_inv_wear_suit()
+			else
+				to_chat(src, "<span class='notice'>Your [leg_clothes.name] protects your legs and feet from the acid!</span>")
+		else
+			. = get_organ("r_leg")
+			if(.)
+				damaged += .
+			. = get_organ("l_leg")
+			if(.)
+				damaged += .
+
+
+	//DAMAGE//
+	for(var/obj/item/organ/external/affecting in damaged)
+		affecting.receive_damage(acidity, 2 * acidity)
+
+		if(istype(affecting, /obj/item/organ/external/head))
+			var/obj/item/organ/external/head/head_organ = affecting
+			if(prob(min(acidpwr * acid_volume / 10, 90))) //Applies disfigurement
+				head_organ.receive_damage(acidity, 2 * acidity)
+				emote("scream")
+				head_organ.h_style = "Bald"
+				head_organ.f_style = "Shaved"
+				update_hair()
+				update_fhair()
+				head_organ.disfigure()
+
+		UpdateDamageIcon()
+
+	//MELTING INVENTORY ITEMS//
+	//these items are all outside of armour visually, so melt regardless.
+	if(!bodyzone_hit)
+		if(back)
+			inventory_items_to_kill += back
+		if(belt)
+			inventory_items_to_kill += belt
+		if(l_hand)
+			inventory_items_to_kill += l_hand
+		if(r_hand)
+			inventory_items_to_kill += r_hand
+
+	for(var/obj/item/I in inventory_items_to_kill)
+		I.acid_act(acidpwr, acid_volume)
+	return 1
+
 /mob/living/carbon/human/emag_act(user as mob, var/obj/item/organ/external/affecting)
 	if(!istype(affecting))
 		return

code/modules/mob/living/living.dm

@@ -266,6 +266,10 @@
 	..()
 	flash_eyes()
 
+/mob/living/acid_act(acidpwr, acid_volume)
+	take_organ_damage(acidpwr * min(1, acid_volume * 0.1))
+	return 1
+
 /mob/living/proc/updatehealth(reason = "none given")
 	if(status_flags & GODMODE)
 		health = maxHealth

code/modules/reagents/chemistry/reagents/toxins.dm

@@ -275,7 +275,7 @@
 	return ..() | update_flags
 
 
-/datum/reagent/sacid
+/datum/reagent/acid
 	name = "Sulphuric acid"
 	id = "sacid"
 	description = "A strong mineral acid with the molecular formula H2SO4."
@@ -283,13 +283,14 @@
 	color = "#00FF32"
 	process_flags = ORGANIC | SYNTHETIC
 	taste_description = "<span class='userdanger'>ACID</span>"
+	var/acidpwr = 10 //the amount of protection removed from the armour
 
-/datum/reagent/sacid/on_mob_life(mob/living/M)
+/datum/reagent/acid/on_mob_life(mob/living/M)
 	var/update_flags = STATUS_UPDATE_NONE
 	update_flags |= M.adjustFireLoss(1, FALSE)
 	return ..() | update_flags
 
-/datum/reagent/sacid/reaction_mob(mob/living/M, method = TOUCH, volume)
+/datum/reagent/acid/reaction_mob(mob/living/M, method = TOUCH, volume)
 	if(ishuman(M) && !isgrey(M))
 		var/mob/living/carbon/human/H = M
 		if(method == TOUCH)
@@ -318,13 +319,62 @@
 				H.adjustFireLoss(min(max(4, (volume - 10) * 2), 20))
 				H.emote("scream")
 
-/datum/reagent/sacid/reaction_obj(obj/O, volume)
-	if((istype(O,/obj/item) || istype(O,/obj/structure/glowshroom)) && prob(40))
-		if(!O.unacidable)
-			var/obj/effect/decal/cleanable/molten_object/I = new/obj/effect/decal/cleanable/molten_object(O.loc)
-			I.desc = "Looks like this was \an [O] some time ago."
-			O.visible_message("<span class='warning'>[O] melts.</span>")
-			qdel(O)
+/datum/reagent/acid/reaction_obj(obj/O, volume)
+	if(ismob(O.loc)) //handled in human acid_act()
+		return
+	volume = round(volume, 0.1)
+	O.acid_act(acidpwr, volume)
+
+/datum/reagent/acid/reaction_turf(turf/T, volume)
+	if(!istype(T))
+		return
+	volume = round(volume, 0.1)
+	T.acid_act(acidpwr, volume)
+
+/datum/reagent/acid/facid
+	name = "Fluorosulfuric Acid"
+	id = "facid"
+	description = "Fluorosulfuric acid is a an extremely corrosive super-acid."
+	color = "#5050FF"
+	acidpwr = 42
+
+/datum/reagent/acid/facid/on_mob_life(mob/living/M)
+	var/update_flags = STATUS_UPDATE_NONE
+	update_flags |= M.adjustToxLoss(1*REAGENTS_EFFECT_MULTIPLIER, FALSE)
+	return ..() | update_flags
+
+/datum/reagent/acid/facid/reaction_mob(mob/living/M, method = TOUCH, volume)
+	if(ishuman(M))
+		var/mob/living/carbon/human/H = M
+		if(method == TOUCH)
+			if(volume > 9)
+				if(!H.wear_mask && !H.head)
+					var/obj/item/organ/external/affecting = H.get_organ("head")
+					if(affecting)
+						affecting.disfigure()
+					H.adjustFireLoss(min(max(8, (volume - 5) * 3), 75))
+					H.emote("scream")
+					return
+				else
+					var/melted_something = FALSE
+					if(H.wear_mask && !H.wear_mask.unacidable)
+						qdel(H.wear_mask)
+						H.update_inv_wear_mask()
+						to_chat(H, "<span class='danger'>Your [H.wear_mask] melts away!</span>")
+						melted_something = TRUE
+
+					if(H.head && !H.head.unacidable)
+						qdel(H.head)
+						H.update_inv_head()
+						to_chat(H, "<span class='danger'>Your [H.head] melts away!</span>")
+						melted_something = TRUE
+					if(melted_something)
+						return
+
+		if(volume >= 5)
+			H.emote("scream")
+			H.adjustFireLoss(min(max(8, (volume - 5) * 3), 75))
+		to_chat(H, "<span class='warning'>The blueish acidic substance stings[volume < 5 ? " you, but isn't concentrated enough to harm you" : null]!</span>")
 
 /datum/reagent/carpotoxin
 	name = "Carpotoxin"
@@ -620,62 +670,6 @@
 		M.emote("scream")
 	return ..() | update_flags
 
-/datum/reagent/facid
-	name = "Fluorosulfuric Acid"
-	id = "facid"
-	description = "Fluorosulfuric acid is a an extremely corrosive super-acid."
-	reagent_state = LIQUID
-	color = "#5050FF"
-	process_flags = ORGANIC | SYNTHETIC
-	taste_description = "<span class='userdanger'>ACID</span>"
-
-/datum/reagent/facid/on_mob_life(mob/living/M)
-	var/update_flags = STATUS_UPDATE_NONE
-	update_flags |= M.adjustToxLoss(1*REAGENTS_EFFECT_MULTIPLIER, FALSE)
-	update_flags |= M.adjustFireLoss(1, FALSE)
-	return ..() | update_flags
-
-/datum/reagent/facid/reaction_mob(mob/living/M, method = TOUCH, volume)
-	if(ishuman(M))
-		var/mob/living/carbon/human/H = M
-		if(method == TOUCH)
-			if(volume > 9)
-				if(!H.wear_mask && !H.head)
-					var/obj/item/organ/external/affecting = H.get_organ("head")
-					if(affecting)
-						affecting.disfigure()
-					H.adjustFireLoss(min(max(8, (volume - 5) * 3), 75))
-					H.emote("scream")
-					return
-				else
-					var/melted_something = FALSE
-					if(H.wear_mask && !H.wear_mask.unacidable)
-						qdel(H.wear_mask)
-						H.update_inv_wear_mask()
-						to_chat(H, "<span class='danger'>Your [H.wear_mask] melts away!</span>")
-						melted_something = TRUE
-
-					if(H.head && !H.head.unacidable)
-						qdel(H.head)
-						H.update_inv_head()
-						to_chat(H, "<span class='danger'>Your [H.head] melts away!</span>")
-						melted_something = TRUE
-					if(melted_something)
-						return
-
-		if(volume >= 5)
-			H.emote("scream")
-			H.adjustFireLoss(min(max(8, (volume - 5) * 3), 75))
-		to_chat(H, "<span class='warning'>The blueish acidic substance stings[volume < 5 ? " you, but isn't concentrated enough to harm you" : null]!</span>")
-
-/datum/reagent/facid/reaction_obj(obj/O, volume)
-	if((istype(O, /obj/item) || istype(O, /obj/structure/glowshroom)))
-		if(!O.unacidable)
-			var/obj/effect/decal/cleanable/molten_object/I = new/obj/effect/decal/cleanable/molten_object(O.loc)
-			I.desc = "Looks like this was \an [O] some time ago."
-			O.visible_message("<span class='warning'>[O] melts.</span>")
-			qdel(O)
-
 /datum/reagent/initropidril
 	name = "Initropidril"
 	id = "initropidril"

code/modules/reagents/chemistry/reagents/water.dm

@@ -24,10 +24,14 @@
 /datum/reagent/water/reaction_mob(mob/living/M, method = TOUCH, volume)
 	M.water_act(volume, water_temperature, src, method)
 
-/datum/reagent/water/reaction_turf(turf/simulated/T, volume)
+/datum/reagent/water/reaction_turf(turf/T, volume)
 	T.water_act(volume, water_temperature, src)
+	var/obj/effect/acid/A = (locate(/obj/effect/acid) in T)
+	if(A)
+		A.acid_level = max(A.acid_level - volume*  50, 0)
 
 /datum/reagent/water/reaction_obj(obj/O, volume)
+	O.acid_level = 0
 	O.water_act(volume, water_temperature, src)
 
 /datum/reagent/lube

paradise.dme

@@ -200,6 +200,7 @@
 #include "code\controllers\master.dm"
 #include "code\controllers\subsystem.dm"
 #include "code\controllers\verbs.dm"
+#include "code\controllers\subsystem\acid.dm"
 #include "code\controllers\subsystem\afk.dm"
 #include "code\controllers\subsystem\air.dm"
 #include "code\controllers\subsystem\alarm.dm"