Attack chain migration: /mob (#28211)

* Attack chain migration: /mob

* always target zone on attack for tests

* thread corgi item interactions through to parent

* put away razor

* standardize test names

* fix harmbaton not beating + stunning

* fix ID cards not unlocking bots

* fix fulton

* fix fulton shenanigans

* fix tumor shards

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

@@ -21,12 +21,13 @@
 	if(volume > 10) // Anything over 10 volume will make the mob wetter.
 		wetlevel = min(wetlevel + 1,5)
 
-/mob/living/carbon/attackby__legacy__attackchain(obj/item/I, mob/user, params)
+/mob/living/carbon/item_interaction(mob/living/user, obj/item/I, list/modifiers)
 	if(length(surgeries))
 		if(user.a_intent == INTENT_HELP)
 			for(var/datum/surgery/S in surgeries)
 				if(S.next_step(user, src))
-					return TRUE
+					return ITEM_INTERACT_COMPLETE
+
 	return ..()
 
 /mob/living/carbon/attack_hand(mob/living/carbon/human/user)

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

@@ -461,10 +461,9 @@ emp_act
 		w_uniform.add_fingerprint(user)
 	return ..()
 
-//Returns TRUE if the attack hit, FALSE if it missed.
-/mob/living/carbon/human/attacked_by__legacy__attackchain(obj/item/I, mob/living/user, def_zone)
+/mob/living/carbon/human/attacked_by(obj/item/I, mob/living/user, def_zone)
 	if(!I || !user)
-		return FALSE
+		return
 
 	if(HAS_TRAIT(I, TRAIT_BUTCHERS_HUMANS) && stat == DEAD && user.a_intent == INTENT_HARM)
 		var/obj/item/food/meat/human/newmeat = new /obj/item/food/meat/human(get_turf(loc))
@@ -479,7 +478,7 @@ emp_act
 		if(!meatleft)
 			add_attack_logs(user, src, "Chopped up into meat")
 			qdel(src)
-			return FALSE
+			return
 
 	var/obj/item/organ/external/affecting = get_organ(ran_zone(user.zone_selected))
 
@@ -492,16 +491,16 @@ emp_act
 	if(user != src)
 		user.do_attack_animation(src)
 		if(check_shields(I, I.force, "the [I.name]", MELEE_ATTACK, I.armour_penetration_flat, I.armour_penetration_percentage))
-			return FALSE
+			return
 
 	send_item_attack_message(I, user, hit_area)
 
 	if(!I.force)
-		return FALSE //item force is zero
+		return //item force is zero
 
 	var/armor = run_armor_check(affecting, MELEE, "<span class='warning'>Your armour has protected your [hit_area].</span>", "<span class='warning'>Your armour has softened hit to your [hit_area].</span>", armour_penetration_flat = I.armour_penetration_flat, armour_penetration_percentage = I.armour_penetration_percentage)
 	if(armor == INFINITY)
-		return FALSE
+		return
 
 	var/weapon_sharp = I.sharp
 	// do not roll for random blunt if the target mob is dead for the ease of decaps
@@ -809,10 +808,10 @@ emp_act
 		O.water_act(volume, temperature, source, method)
 
 
-
-/mob/living/carbon/human/attackby__legacy__attackchain(obj/item/I, mob/user, params)
+/mob/living/carbon/human/attack_by(obj/item/I, mob/living/user, params)
 	if(SEND_SIGNAL(src, COMSIG_HUMAN_ATTACKED, user) & COMPONENT_CANCEL_ATTACK_CHAIN)
-		return TRUE
+		return FINISH_ATTACK
+
 	return ..()
 
 /mob/living/carbon/human/is_eyes_covered(check_glasses = TRUE, check_head = TRUE, check_mask = TRUE)

code/modules/mob/living/silicon/decoy/decoy.dm

@@ -6,10 +6,10 @@
 	mobility_flags = 0
 	a_intent = INTENT_HARM // This is apparently the only thing that stops other mobs walking through them as if they were thin air.
 
-/mob/living/silicon/decoy/attackby__legacy__attackchain(obj/item/W, mob/user, params)
+/mob/living/silicon/decoy/item_interaction(mob/living/user, obj/item/W, list/modifiers)
 	if(istype(W, /obj/item/aicard))
 		to_chat(user, "<span class='warning'>You cannot find an intellicard slot on [src].</span>")
-		return TRUE
+		return ITEM_INTERACT_COMPLETE
 	else
 		return ..()
 

code/modules/mob/living/silicon/pai/pai.dm

@@ -289,7 +289,7 @@
 	update_icons()
 
 //Overriding this will stop a number of headaches down the track.
-/mob/living/silicon/pai/attackby__legacy__attackchain(obj/item/W as obj, mob/user as mob, params)
+/mob/living/silicon/pai/item_interaction(mob/living/user, obj/item/W, list/modifiers)
 	if(istype(W, /obj/item/stack/nanopaste))
 		var/obj/item/stack/nanopaste/N = W
 		if(stat == DEAD)
@@ -302,8 +302,13 @@
 		else
 			to_chat(user, "<span class='notice'>All [name]'s systems are nominal.</span>")
 
-		return
-	else if(W.force)
+		return ITEM_INTERACT_COMPLETE
+
+/mob/living/silicon/pai/attack_by(obj/item/W, mob/living/user, params)
+	if(..())
+		return FINISH_ATTACK
+
+	if(W.force)
 		visible_message("<span class='danger'>[user.name] attacks [src] with [W]!</span>")
 		adjustBruteLoss(W.force)
 	else
@@ -311,7 +316,6 @@
 	spawn(1)
 		if(stat != 2)
 			close_up()
-	return
 
 /mob/living/silicon/pai/welder_act()
 	return

code/modules/mob/living/silicon/robot/drone/maint_drone.dm

@@ -155,10 +155,10 @@
 	. += "<span class='notice'><i>The ever-loyal workers of Nanotrasen facilities. Known for their small and cute look, these drones seek only to repair damaged parts of the station, being lawed against hurting even a spiderling. These fine drones are programmed against interfering with any business of anyone, so they won't do anything you don't want them to.</i></span>"
 
 //Drones cannot be upgraded with borg modules so we need to catch some items before they get used in ..().
-/mob/living/silicon/robot/drone/attackby__legacy__attackchain(obj/item/I, mob/user, params)
+/mob/living/silicon/robot/drone/item_interaction(mob/living/user, obj/item/I, list/modifiers)
 	if(istype(I, /obj/item/borg/upgrade))
 		to_chat(user, "<span class='warning'>The maintenance drone chassis is not compatible with [I].</span>")
-		return
+		return ITEM_INTERACT_COMPLETE
 
 	else if(istype(I, /obj/item/card/id) || istype(I, /obj/item/pda))
 		if(stat == DEAD)
@@ -186,7 +186,7 @@
 					drones++
 			if(drones < config.max_maint_drones)
 				request_player()*/
-			return
+			return ITEM_INTERACT_COMPLETE
 
 		else
 			var/confirm = tgui_alert(user, "Using your ID on a Maintenance Drone will shut it down, are you sure you want to do this?", "Disable Drone", list("Yes", "No"))
@@ -201,9 +201,9 @@
 				else
 					to_chat(user, "<span class='warning'>Access denied.</span>")
 
-		return
+		return ITEM_INTERACT_COMPLETE
 
-	..()
+	return ..()
 
 /mob/living/silicon/robot/drone/crowbar_act(mob/user, obj/item/I)
 	. = TRUE

code/modules/mob/living/silicon/robot/robot_mob.dm

@@ -921,7 +921,7 @@ GLOBAL_LIST_INIT(robot_verbs_default, list(
 	return 2
 
 
-/mob/living/silicon/robot/attackby__legacy__attackchain(obj/item/W, mob/user, params)
+/mob/living/silicon/robot/item_interaction(mob/living/user, obj/item/W, list/modifiers)
 	// Check if the user is trying to insert another component like a radio, actuator, armor etc.
 	if(istype(W, /obj/item/robot_parts/robot_component) && opened)
 		for(var/V in components)
@@ -930,22 +930,22 @@ GLOBAL_LIST_INIT(robot_verbs_default, list(
 				continue
 			if(!user.drop_item())
 				to_chat(user, "<span class='warning'>[W] seems to be stuck in your hand!</span>")
-				return
+				return ITEM_INTERACT_COMPLETE
 			var/obj/item/robot_parts/robot_component/WC = W
 			C.brute_damage = WC.brute
 			C.electronics_damage = WC.burn
 			C.install(WC)
 			to_chat(usr, "<span class='notice'>You install [W].</span>")
-			return
+			return ITEM_INTERACT_COMPLETE
 
 	if(istype(W, /obj/item/stack/cable_coil) && user.a_intent == INTENT_HELP && (wiresexposed || isdrone(src)))
 		user.changeNext_move(CLICK_CD_MELEE)
 		if(!getFireLoss())
 			to_chat(user, "<span class='notice'>Nothing to fix!</span>")
-			return
+			return ITEM_INTERACT_COMPLETE
 		else if(!getFireLoss(TRUE))
 			to_chat(user, "<span class='warning'>The damaged components are beyond saving!</span>")
-			return
+			return ITEM_INTERACT_COMPLETE
 		var/obj/item/stack/cable_coil/coil = W
 		adjustFireLoss(-30)
 		updatehealth()
@@ -976,13 +976,13 @@ GLOBAL_LIST_INIT(robot_verbs_default, list(
 
 			module?.update_cells()
 			diag_hud_set_borgcell()
-
+		return ITEM_INTERACT_COMPLETE
 	else if(istype(W, /obj/item/encryptionkey/) && opened)
 		if(radio)//sanityyyyyy
 			radio.attackby__legacy__attackchain(W,user)//GTFO, you have your own procs
 		else
 			to_chat(user, "Unable to locate a radio.")
-
+		return ITEM_INTERACT_COMPLETE
 	else if(istype(W, /obj/item/card/id) || istype(W, /obj/item/pda))			// trying to unlock the interface with an ID card
 		if(emagged)//still allow them to open the cover
 			to_chat(user, "The interface seems slightly damaged.")
@@ -996,7 +996,7 @@ GLOBAL_LIST_INIT(robot_verbs_default, list(
 				update_icons()
 			else
 				to_chat(user, "<span class='warning'>Access denied.</span>")
-
+		return ITEM_INTERACT_COMPLETE
 	else if(istype(W, /obj/item/borg/upgrade/))
 		var/obj/item/borg/upgrade/U = W
 		if(!opened)
@@ -1006,18 +1006,18 @@ GLOBAL_LIST_INIT(robot_verbs_default, list(
 		else
 			if(U.action(user, src))
 				user.visible_message("<span class='notice'>[user] applied [U] to [src].</span>", "<span class='notice'>You apply [U] to [src].</span>")
-
+		return ITEM_INTERACT_COMPLETE
 
 	else if(istype(W, /obj/item/mmi_radio_upgrade))
 		if(!opened)
 			to_chat(user, "<span class='warning'>You must access the borg's internals!</span>")
-			return
+			return ITEM_INTERACT_COMPLETE
 		else if(!mmi)
 			to_chat(user, "<span class='warning'>This cyborg does not have an MMI to augment!</span>")
-			return
+			return ITEM_INTERACT_COMPLETE
 		else if(mmi.radio)
 			to_chat(user, "<span class='warning'>A radio upgrade is already installed in the MMI!</span>")
-			return
+			return ITEM_INTERACT_COMPLETE
 		else if(user.drop_item())
 			to_chat(user, "<span class='notice'>You apply the upgrade to [src].</span>")
 			to_chat(src, "<span class='notice'>MMI radio capability installed.</span>")
@@ -1133,7 +1133,7 @@ GLOBAL_LIST_INIT(robot_verbs_default, list(
 
 
 
-/mob/living/silicon/robot/attacked_by__legacy__attackchain(obj/item/I, mob/living/user, def_zone)
+/mob/living/silicon/robot/attacked_by(obj/item/I, mob/living/user, def_zone)
 	if(I.force && I.damtype != STAMINA && stat != DEAD) //only sparks if real damage is dealt.
 		spark_system.start()
 	..()

code/modules/mob/living/silicon/robot/syndicate_robot.dm

@@ -118,10 +118,10 @@
 			return
 	cham_proj.attack_self__legacy__attackchain(src)
 
-/mob/living/silicon/robot/syndicate/saboteur/attackby__legacy__attackchain()
+/mob/living/silicon/robot/syndicate/saboteur/attack_by(obj/item/attacking, mob/living/user, params)
+	. = ..()
 	if(cham_proj)
 		cham_proj.disrupt(src)
-	..()
 
 /mob/living/silicon/robot/syndicate/saboteur/attack_hand()
 	if(cham_proj)

code/modules/mob/living/silicon/silicon_mob.dm

@@ -286,10 +286,14 @@
 
 	return 2
 
-/mob/living/silicon/attacked_by__legacy__attackchain(obj/item/I, mob/living/user, def_zone)
+/mob/living/silicon/item_interaction(mob/living/user, obj/item/I, list/modifiers)
 	if(istype(I, /obj/item/clothing/head) && user.a_intent == INTENT_HELP)
 		place_on_head(user.get_active_hand(), user)
-		return TRUE
+		return ITEM_INTERACT_COMPLETE
+
+	return ..()
+
+/mob/living/silicon/attacked_by(obj/item/I, mob/living/user, def_zone)
 	send_item_attack_message(I, user)
 	if(I.force)
 		var/bonus_damage = 0

code/modules/mob/living/simple_animal/animal_defense.dm

@@ -1,9 +1,7 @@
-/mob/living/simple_animal/attackby__legacy__attackchain(obj/item/O, mob/living/user)
+/mob/living/simple_animal/item_interaction(mob/living/user, obj/item/O, list/modifiers)
 	if(can_collar && istype(O, /obj/item/petcollar) && !pcollar)
 		add_collar(O, user)
-		return
-	else
-		return ..()
+		return ITEM_INTERACT_COMPLETE
 
 /mob/living/simple_animal/attack_hand(mob/living/carbon/human/M)
 	..()

code/modules/mob/living/simple_animal/bot/bot.dm

@@ -423,44 +423,44 @@
 /mob/living/simple_animal/bot/proc/interact(mob/user)
 	show_controls(user)
 
-/mob/living/simple_animal/bot/attackby__legacy__attackchain(obj/item/W, mob/user, params)
+/mob/living/simple_animal/bot/item_interaction(mob/living/user, obj/item/W, list/modifiers)
 	if(istype(W, /obj/item/card/id) || istype(W, /obj/item/pda))
 		if(allowed(user) && !open && !emagged)
 			locked = !locked
 			to_chat(user, "Controls are now [locked ? "locked." : "unlocked."]")
-			return
+			return ITEM_INTERACT_COMPLETE
 		if(emagged)
 			to_chat(user, "<span class='danger'>ERROR</span>")
 		if(open)
 			to_chat(user, "<span class='warning'>Please close the access panel before locking it.</span>")
 		else
 			to_chat(user, "<span class='warning'>Access denied.</span>")
-		return
+		return ITEM_INTERACT_COMPLETE
 
 	if(istype(W, /obj/item/paicard))
 		if(paicard)
 			to_chat(user, "<span class='warning'>A [paicard] is already inserted!</span>")
-			return
+			return ITEM_INTERACT_COMPLETE
 
 		if(!allow_pai || key)
 			to_chat(user, "<span class='warning'>[src] is not compatible with [W].</span>")
-			return
+			return ITEM_INTERACT_COMPLETE
 
 		if(locked || open || hijacked)
 			to_chat(user, "<span class='warning'>The personality slot is locked.</span>")
-			return
+			return ITEM_INTERACT_COMPLETE
 
 		var/obj/item/paicard/card = W
 		if(!card.pai?.mind)
 			to_chat(user, "<span class='warning'>[W] is inactive.</span>")
-			return
+			return ITEM_INTERACT_COMPLETE
 
 		if(!card.pai.ckey || jobban_isbanned(card.pai, ROLE_SENTIENT))
 			to_chat(user, "<span class='warning'>[W] is unable to establish a connection to [src].</span>")
-			return
+			return ITEM_INTERACT_COMPLETE
 
 		if(!user.drop_item())
-			return
+			return ITEM_INTERACT_COMPLETE
 
 		W.forceMove(src)
 		paicard = card
@@ -471,20 +471,19 @@
 		name = paicard.pai.name
 		faction = user.faction
 		add_attack_logs(user, paicard.pai, "Uploaded to [src.bot_name]")
-		return
+		return ITEM_INTERACT_COMPLETE
 
 	if(istype(W, /obj/item/hemostat) && paicard)
 		if(open)
 			to_chat(user, "<span class='warning'>Close the access panel before manipulating the personality slot!</span>")
-			return
+			return ITEM_INTERACT_COMPLETE
 
 		to_chat(user, "<span class='notice'>You attempt to pull [paicard] free...</span>")
 		if(do_after(user, 30 * W.toolspeed, target = src))
 			if(paicard)
 				user.visible_message("<span class='notice'>[user] uses [W] to pull [paicard] out of [bot_name]!</span>","<span class='notice'>You pull [paicard] out of [bot_name] with [W].</span>")
 				ejectpai(user)
-				return
-	return ..()
+				return ITEM_INTERACT_COMPLETE
 
 /mob/living/simple_animal/bot/screwdriver_act(mob/living/user, obj/item/I)
 	if(user.a_intent == INTENT_HARM)

code/modules/mob/living/simple_animal/bot/cleanbot.dm

@@ -88,7 +88,7 @@
 	text_dehack = "[name]'s software has been reset!"
 	text_dehack_fail = "[name] does not seem to respond to your repair code!"
 
-/mob/living/simple_animal/bot/cleanbot/attackby__legacy__attackchain(obj/item/W, mob/user, params)
+/mob/living/simple_animal/bot/cleanbot/item_interaction(mob/living/user, obj/item/W, list/modifiers)
 	if(istype(W, /obj/item/card/id)||istype(W, /obj/item/pda))
 		if(allowed(user) && !open && !emagged)
 			locked = !locked
@@ -100,8 +100,10 @@
 				to_chat(user, "<span class='warning'>Please close the access panel before locking it.</span>")
 			else
 				to_chat(user, "<span class='notice'>\The [src] doesn't seem to respect your authority.</span>")
-	else
-		return ..()
+
+		return ITEM_INTERACT_COMPLETE
+
+	return ..()
 
 /mob/living/simple_animal/bot/cleanbot/emag_act(mob/user)
 	..()

code/modules/mob/living/simple_animal/bot/ed209bot.dm

@@ -184,8 +184,10 @@
 		retaliate(H)
 	return ..()
 
-/mob/living/simple_animal/bot/ed209/attackby__legacy__attackchain(obj/item/W, mob/user, params)
-	..()
+/mob/living/simple_animal/bot/ed209/attack_by(obj/item/W, mob/living/user, params)
+	if(..())
+		return FINISH_ATTACK
+
 	if(W.force && !target && W.damtype != STAMINA)
 		retaliate(user)
 		if(lasercolor)//To make up for the fact that lasertag bots don't hunt

code/modules/mob/living/simple_animal/bot/floorbot.dm

@@ -133,11 +133,11 @@
 		if("ejectpai")
 			ejectpai()
 
-/mob/living/simple_animal/bot/floorbot/attackby__legacy__attackchain(obj/item/W , mob/user, params)
+/mob/living/simple_animal/bot/floorbot/item_interaction(mob/living/user, obj/item/W, list/modifiers)
 	if(istype(W, /obj/item/stack/tile/plasteel))
 		var/obj/item/stack/tile/plasteel/T = W
 		if(amount >= MAX_AMOUNT)
-			return
+			return ITEM_INTERACT_COMPLETE
 		var/loaded = min(MAX_AMOUNT - amount, T.amount)
 		T.use(loaded)
 		amount += loaded
@@ -147,8 +147,10 @@
 			update_icon()
 		else
 			to_chat(user, "<span class='warning'>You need at least one floor tile to put into [src]!</span>")
-	else
-		..()
+
+		return ITEM_INTERACT_COMPLETE
+
+	return ..()
 
 /mob/living/simple_animal/bot/floorbot/emag_act(mob/user)
 	..()

code/modules/mob/living/simple_animal/bot/griefsky.dm

@@ -221,14 +221,15 @@
 			return
 	return ..()
 
-/mob/living/simple_animal/bot/secbot/griefsky/attackby__legacy__attackchain(obj/item/W, mob/user, params) //cant touch or attack him while spinning
+// cant touch or attack him while spinning
+/mob/living/simple_animal/bot/secbot/griefsky/attack_by(obj/item/W, mob/living/user, params)
+	if(..())
+		return FINISH_ATTACK
+
 	if(src.icon_state == spin_icon)
 		if(prob(block_chance_melee))
 			user.changeNext_move(CLICK_CD_MELEE)
 			user.do_attack_animation(src)
 			visible_message("[src] deflects [user]'s move with his energy swords!")
 			playsound(loc, 'sound/weapons/blade1.ogg', 50, TRUE, -1)
-		else
-			return ..()
-	else
-		return ..()
+			return FINISH_ATTACK

code/modules/mob/living/simple_animal/bot/honkbot.dm

@@ -116,13 +116,14 @@
 		addtimer(CALLBACK(src, PROC_REF(react_buzz)), 5)
 	return ..()
 
-/mob/living/simple_animal/bot/honkbot/attackby__legacy__attackchain(obj/item/W, mob/user, params)
-	..()
-	if(istype(W, /obj/item/weldingtool) && user.a_intent != INTENT_HARM) // Any intent but harm will heal, so we shouldn't get angry.
-		return
-	if(!isscrewdriver(W) && !locked && (W.force) && (!target) && (W.damtype != STAMINA))//If the target is locked, they are recieving damage from the screwdriver
+/mob/living/simple_animal/bot/honkbot/item_interaction(mob/living/user, obj/item/W, list/modifiers)
+	// If the target is locked, they are recieving damage from the screwdriver
+	if(!isscrewdriver(W) && !locked && (W.force) && (!target) && (W.damtype != STAMINA))
 		retaliate(user)
 		addtimer(CALLBACK(src, PROC_REF(react_buzz)), 5)
+		return ITEM_INTERACT_COMPLETE
+
+	return ..()
 
 /mob/living/simple_animal/bot/honkbot/emag_act(mob/user)
 	..()

code/modules/mob/living/simple_animal/bot/medbot.dm

@@ -275,28 +275,31 @@
 			reagent_glass.forceMove(get_turf(src))
 			reagent_glass = null
 
-/mob/living/simple_animal/bot/medbot/attackby__legacy__attackchain(obj/item/W, mob/user, params)
+/mob/living/simple_animal/bot/medbot/item_interaction(mob/living/user, obj/item/W, list/modifiers)
 	if(istype(W, /obj/item/reagent_containers/glass))
-		. = TRUE //no afterattack
 		if(locked)
 			to_chat(user, "<span class='warning'>You cannot insert a beaker because the panel is locked!</span>")
-			return
+			return ITEM_INTERACT_COMPLETE
 		if(!isnull(reagent_glass))
 			to_chat(user, "<span class='warning'>There is already a beaker loaded!</span>")
-			return
+			return ITEM_INTERACT_COMPLETE
 		if(!user.drop_item())
-			return
+			return ITEM_INTERACT_COMPLETE
 
 		W.forceMove(src)
 		reagent_glass = W
 		to_chat(user, "<span class='notice'>You insert [W].</span>")
 		ui_interact(user)
 
-	else
-		var/current_health = health
-		..()
-		if(health < current_health) //if medbot took some damage
-			step_to(src, (get_step_away(src,user)))
+		return ITEM_INTERACT_COMPLETE
+
+	return ..()
+
+/mob/living/simple_animal/bot/medbot/attacked_by(obj/item/attacker, mob/living/user)
+	var/current_health = health
+	. = ..()
+	if(health < current_health) //if medbot took some damage
+		step_to(src, (get_step_away(src,user)))
 
 /mob/living/simple_animal/bot/medbot/emag_act(mob/user)
 	..()

code/modules/mob/living/simple_animal/bot/mulebot.dm

@@ -100,16 +100,18 @@
 	..()
 	reached_target = 0
 
-/mob/living/simple_animal/bot/mulebot/attackby__legacy__attackchain(obj/item/I, mob/user, params)
+/mob/living/simple_animal/bot/mulebot/item_interaction(mob/living/user, obj/item/I, list/modifiers)
 	if(istype(I,/obj/item/stock_parts/cell) && open && !cell)
 		if(!user.drop_item())
-			return
+			return ITEM_INTERACT_COMPLETE
 		var/obj/item/stock_parts/cell/C = I
 		C.forceMove(src)
 		cell = C
 		visible_message("[user] inserts a cell into [src].",
 						"<span class='notice'>You insert the new cell into [src].</span>")
 		update_controls()
+		update_icon()
+		return ITEM_INTERACT_COMPLETE
 	else if(load && ismob(load))  // chance to knock off rider
 		if(prob(1 + I.force * 2))
 			unload(0)
@@ -117,11 +119,10 @@
 									"<span class='danger'>You knock [load] off [src] with \the [I]!</span>")
 		else
 			to_chat(user, "<span class='warning'>You hit [src] with \the [I] but to no effect!</span>")
-			..()
-	else
-		..()
-	update_icon()
-	return
+		update_icon()
+		return ITEM_INTERACT_COMPLETE
+
+	return ..()
 
 /mob/living/simple_animal/bot/mulebot/crowbar_act(mob/living/user, obj/item/I)
 	if(!open || !cell)

code/modules/mob/living/simple_animal/bot/secbot.dm

@@ -196,8 +196,10 @@
 		retaliate(H)
 	return ..()
 
-/mob/living/simple_animal/bot/secbot/attackby__legacy__attackchain(obj/item/W, mob/user, params)
-	..()
+/mob/living/simple_animal/bot/secbot/attacked_by(obj/item/W, mob/living/user)
+	if(..())
+		return FINISH_ATTACK
+
 	if(W.force && !target && W.damtype != STAMINA)
 		retaliate(user)
 

code/modules/mob/living/simple_animal/clockwork_constructs.dm

@@ -51,18 +51,16 @@
 	playsound(src, 'sound/effects/pylon_shatter.ogg', 40, TRUE)
 	return ..()
 
-/mob/living/simple_animal/hostile/clockwork_construct/clockwork_marauder/attacked_by__legacy__attackchain(obj/item/I, mob/living/user)
+/mob/living/simple_animal/hostile/clockwork_construct/clockwork_marauder/attacked_by(obj/item/I, mob/living/user)
+	if(..())
+		return FINISH_ATTACK
+
 	if(istype(I, /obj/item/nullrod))
 		adjustFireLoss(15)
 		if(shield_health > 0)
 			damage_shield()
 		playsound(src,'sound/hallucinations/veryfar_noise.ogg', 40, 1)
 
-	if((I.tool_behaviour == TOOL_WELDER) && (user.a_intent == INTENT_HELP))
-		welder_act(user, I)
-		return
-	. = ..()
-
 /mob/living/simple_animal/hostile/clockwork_construct/clockwork_marauder/bullet_act(obj/item/projectile/Proj)
 	if(shield_health > 0)
 		damage_shield()

code/modules/mob/living/simple_animal/friendly/dog.dm

@@ -22,7 +22,6 @@
 	var/last_eaten = 0
 	footstep_type = FOOTSTEP_MOB_CLAW
 	var/next_spin_message = 0
-	var/razor_shave_delay = 5 SECONDS
 
 /mob/living/simple_animal/pet/dog/npc_safe(mob/user)
 	return TRUE
@@ -84,6 +83,7 @@
 	var/list/strippable_inventory_slots = list()
 	var/shaved = FALSE
 	var/nofur = FALSE 		//Corgis that have risen past the material plane of existence.
+	var/razor_shave_delay = 5 SECONDS
 
 /mob/living/simple_animal/pet/dog/corgi/Initialize(mapload)
 	. = ..()
@@ -185,14 +185,14 @@
 			armorval += inventory_back.armor.getRating(type)
 	return armorval * 0.5
 
-/mob/living/simple_animal/pet/dog/corgi/attackby__legacy__attackchain(obj/item/O, mob/user, params)
+/mob/living/simple_animal/pet/dog/corgi/item_interaction(mob/living/user, obj/item/O, list/modifiers)
 	if(istype(O, /obj/item/razor))
 		if(shaved)
 			to_chat(user, "<span class='warning'>You can't shave this corgi, it's already been shaved!</span>")
-			return
+			return ITEM_INTERACT_COMPLETE
 		if(nofur)
 			to_chat(user, "<span class='warning'>You can't shave this corgi, it doesn't have a fur coat!</span>")
-			return
+			return ITEM_INTERACT_COMPLETE
 		user.visible_message("<span class='notice'>[user] starts to shave [src] using \the [O].", "<span class='notice'>You start to shave [src] using \the [O]...</span>")
 		if(do_after(user, razor_shave_delay, target = src))
 			user.visible_message("<span class='notice'>[user] shaves [src]'s hair using \the [O].</span>")
@@ -204,9 +204,10 @@
 				icon_state = icon_living
 			else
 				icon_state = icon_dead
-		return
-	..()
-	update_corgi_fluff()
+		update_corgi_fluff()
+		return ITEM_INTERACT_COMPLETE
+
+	return ..()
 
 //Corgis are supposed to be simpler, so only a select few objects can actually be put
 //to be compatible with them. The objects are below.

code/modules/mob/living/simple_animal/friendly/farm_animals.dm

@@ -73,11 +73,10 @@
 	if(stat == CONSCIOUS)
 		eat_plants()
 
-/mob/living/simple_animal/hostile/retaliate/goat/attackby__legacy__attackchain(obj/item/O as obj, mob/user as mob, params)
+/mob/living/simple_animal/hostile/retaliate/goat/item_interaction(mob/living/user, obj/item/O, list/modifiers)
 	if(stat == CONSCIOUS && istype(O, /obj/item/reagent_containers/glass))
 		udder.milkAnimal(O, user)
-	else
-		return ..()
+		return ITEM_INTERACT_COMPLETE
 
 /mob/living/simple_animal/hostile/retaliate/goat/proc/eat_plants()
 	var/eaten = FALSE
@@ -146,12 +145,10 @@
 	QDEL_NULL(udder)
 	return ..()
 
-/mob/living/simple_animal/cow/attackby__legacy__attackchain(obj/item/O, mob/user, params)
+/mob/living/simple_animal/cow/item_interaction(mob/living/user, obj/item/O, list/modifiers)
 	if(stat == CONSCIOUS && istype(O, /obj/item/reagent_containers/glass))
 		udder.milkAnimal(O, user)
-		return TRUE
-	else
-		return ..()
+		return ITEM_INTERACT_COMPLETE
 
 /mob/living/simple_animal/cow/Life(seconds, times_fired)
 	. = ..()
@@ -319,7 +316,7 @@ GLOBAL_VAR_INIT(chicken_count, 0)
 		return
 	GLOB.chicken_count -= 1
 
-/mob/living/simple_animal/chicken/attackby__legacy__attackchain(obj/item/O, mob/user, params)
+/mob/living/simple_animal/chicken/item_interaction(mob/living/user, obj/item/O, list/modifiers)
 	if(istype(O, food_type)) //feedin' dem chickens
 		if(stat == CONSCIOUS && eggsleft < 8)
 			var/feedmsg = "[user] feeds [O] to [name]! [pick(feedMessages)]"
@@ -330,8 +327,8 @@ GLOBAL_VAR_INIT(chicken_count, 0)
 			//world << eggsleft
 		else
 			to_chat(user, "<span class='warning'>[name] doesn't seem hungry!</span>")
-	else
-		..()
+
+		return ITEM_INTERACT_COMPLETE
 
 /mob/living/simple_animal/chicken/attack_hand(mob/living/carbon/human/M)
 	if(M.a_intent == INTENT_HELP)

code/modules/mob/living/simple_animal/friendly/nian_caterpillar.dm

@@ -124,11 +124,11 @@
 	else
 		get_scooped(M)
 
-/mob/living/simple_animal/nian_caterpillar/attacked_by__legacy__attackchain(obj/item/I, mob/living/user, def_zone)
+/mob/living/simple_animal/nian_caterpillar/attacked_by(obj/item/I, mob/living/user)
+	if(..())
+		return FINISH_ATTACK
 	if(istype(I, /obj/item/melee/flyswatter) && I.force)
 		gib() // Commit die.
-	else
-		..()
 
 /datum/action/innate/nian_caterpillar_emerge
 	name = "Evolve"

code/modules/mob/living/simple_animal/friendly/pet.dm

@@ -7,11 +7,12 @@
 	speed = 0 // same speed as a person.
 	hud_type = /datum/hud/corgi
 
-/mob/living/simple_animal/pet/attackby__legacy__attackchain(obj/item/O, mob/user, params)
+/mob/living/simple_animal/pet/item_interaction(mob/living/user, obj/item/O, list/modifiers)
 	if(!istype(O, /obj/item/newspaper))
 		return ..()
 	var/obj/item/newspaper/paper = O
 	if(stat != CONSCIOUS || !paper.rolled)
-		return
+		return ..()
 	user.visible_message("<span class='notice'>[user] baps [name] on the nose with the rolled up [O].</span>")
 	INVOKE_ASYNC(src, PROC_REF(spin), 7 DECISECONDS, 1)
+	return ITEM_INTERACT_COMPLETE

code/modules/mob/living/simple_animal/friendly/spiderbot.dm

@@ -46,15 +46,15 @@
 		eject_brain()
 	return ..()
 
-/mob/living/simple_animal/spiderbot/attackby__legacy__attackchain(obj/item/O, mob/living/user, params)
+/mob/living/simple_animal/spiderbot/item_interaction(mob/living/user, obj/item/O, list/modifiers)
 	if(istype(O, /obj/item/mmi))
 		var/obj/item/mmi/B = O
 		if(mmi) //There's already a brain in it.
 			to_chat(user, "<span class='warning'>There's already a brain in [src]!</span>")
-			return
+			return ITEM_INTERACT_COMPLETE
 		if(!B.brainmob)
 			to_chat(user, "<span class='warning'>Sticking an empty MMI into the frame would sort of defeat the purpose.</span>")
-			return
+			return ITEM_INTERACT_COMPLETE
 		if(!B.brainmob.key)
 			var/ghost_can_reenter = 0
 			if(B.brainmob.mind)
@@ -68,15 +68,15 @@
 						break
 			if(!ghost_can_reenter)
 				to_chat(user, "<span class='notice'>[B] is completely unresponsive; there's no point.</span>")
-				return
+				return ITEM_INTERACT_COMPLETE
 
 		if(B.brainmob.stat == DEAD)
 			to_chat(user, "<span class='warning'>[B] is dead. Sticking it into the frame would sort of defeat the purpose.</span>")
-			return
+			return ITEM_INTERACT_COMPLETE
 
 		if(jobban_isbanned(B.brainmob, "Cyborg") || jobban_isbanned(B.brainmob, "nonhumandept"))
 			to_chat(user, "<span class='warning'>[B] does not seem to fit.</span>")
-			return
+			return ITEM_INTERACT_COMPLETE
 
 		to_chat(user, "<span class='notice'>You install [B] in [src]!</span>")
 
@@ -86,16 +86,16 @@
 		transfer_personality(B)
 
 		update_icon()
-		return 1
+		return ITEM_INTERACT_COMPLETE
 
 	else if(istype(O, /obj/item/card/id) || istype(O, /obj/item/pda))
 		if(!mmi)
 			to_chat(user, "<span class='warning'>There's no reason to swipe your ID - the spiderbot has no brain to remove.</span>")
-			return 0
+			return ITEM_INTERACT_COMPLETE
 
 		if(emagged)
 			to_chat(user, "<span class='warning'>[src] doesn't seem to respond.</span>")
-			return 0
+			return ITEM_INTERACT_COMPLETE
 
 		var/obj/item/card/id/id_card
 
@@ -108,13 +108,10 @@
 		if(ACCESS_ROBOTICS in id_card.access)
 			to_chat(user, "<span class='notice'>You swipe your access card and pop the brain out of [src].</span>")
 			eject_brain()
-			return 1
+			return ITEM_INTERACT_COMPLETE
 		else
 			to_chat(user, "<span class='warning'>You swipe your card, with no effect.</span>")
-			return 0
-
-	else
-		..()
+			return ITEM_INTERACT_COMPLETE
 
 /mob/living/simple_animal/spiderbot/welder_act(mob/user, obj/item/I)
 	if(user.a_intent != INTENT_HELP)

code/modules/mob/living/simple_animal/hostile/hellhound.dm

@@ -92,8 +92,10 @@
 		return TRUE
 	return FALSE
 
-/mob/living/simple_animal/hostile/hellhound/attackby__legacy__attackchain(obj/item/C, mob/user, params)
-	. = ..()
+/mob/living/simple_animal/hostile/hellhound/attacked_by(obj/item/attacker, mob/living/user)
+	if(..())
+		return FINISH_ATTACK
+
 	if(target && isliving(target))
 		var/mob/living/L = target
 		if(L.stat != CONSCIOUS)

code/modules/mob/living/simple_animal/hostile/hostile.dm

@@ -115,10 +115,12 @@
 		Move(get_step(src, chosen_dir))
 		face_atom(target) //Looks better if they keep looking at you when dodging
 
-/mob/living/simple_animal/hostile/attacked_by__legacy__attackchain(obj/item/I, mob/living/user)
+/mob/living/simple_animal/hostile/attacked_by(obj/item/attacker, mob/living/user)
+	if(..())
+		return FINISH_ATTACK
+
 	if(stat == CONSCIOUS && !target && AIStatus != AI_OFF && !client && user)
 		FindTarget(list(user), 1)
-	return ..()
 
 /mob/living/simple_animal/hostile/bullet_act(obj/item/projectile/P)
 	if(stat == CONSCIOUS && !target && AIStatus != AI_OFF && !client)

code/modules/mob/living/simple_animal/hostile/megafauna/ancient_robot.dm

@@ -344,9 +344,12 @@ Difficulty: Hard
 	if(P.damage)
 		disable_shield()
 
-/mob/living/simple_animal/hostile/megafauna/ancient_robot/attacked_by__legacy__attackchain(obj/item/I, mob/living/user)
+/mob/living/simple_animal/hostile/megafauna/ancient_robot/attacked_by(obj/item/I, mob/living/user)
+	if(..())
+		return FINISH_ATTACK
+
 	if(!body_shield_enabled)
-		return ..()
+		return
 	do_sparks(2, 1, src)
 	visible_message("<span class='danger'>[src]'s shield deflects [I] in a shower of sparks!</span>", "<span class='userdanger'>You deflect the attack!</span>")
 	if(I.force)

code/modules/mob/living/simple_animal/hostile/mining/elites/elite.dm

@@ -425,14 +425,17 @@ While using this makes the system rely on OnFire, it still gives options for tim
 	w_class = WEIGHT_CLASS_SMALL
 	throw_speed = 3
 	throw_range = 5
+	new_attack_chain = TRUE
 
-/obj/item/tumor_shard/afterattack__legacy__attackchain(atom/target, mob/user, proximity_flag)
-	. = ..()
-	if(istype(target, /mob/living/simple_animal/hostile/asteroid/elite) && proximity_flag)
+/obj/item/tumor_shard/interact_with_atom(atom/target, mob/living/user, list/modifiers)
+	user.changeNext_move(CLICK_CD_MELEE)
+	user.do_attack_animation(target)
+
+	if(istype(target, /mob/living/simple_animal/hostile/asteroid/elite))
 		var/mob/living/simple_animal/hostile/asteroid/elite/E = target
 		if(E.stat != DEAD || E.sentience_type != SENTIENCE_BOSS || !E.key)
 			user.visible_message("It appears [E] is unable to be revived right now. Perhaps try again later.")
-			return
+			return ITEM_INTERACT_COMPLETE
 		E.faction = list("\ref[user]")
 		E.friends += user
 		E.revive()
@@ -453,6 +456,8 @@ While using this makes the system rely on OnFire, it still gives options for tim
 	else
 		to_chat(user, "<span class='notice'>[src] only works on the corpse of a sentient lavaland elite.</span>")
 
+	return ITEM_INTERACT_COMPLETE
+
 /obj/effect/temp_visual/elite_tumor_wall
 	name = "magic wall"
 	icon = 'icons/turf/walls/hierophant_wall_temp.dmi'

code/modules/mob/living/simple_animal/hostile/mining/gutlunch.dm

@@ -58,12 +58,11 @@
 	if(udder.reagents.total_volume == udder.reagents.maximum_volume)
 		add_overlay("gl_full")
 
-/mob/living/simple_animal/hostile/asteroid/gutlunch/attackby__legacy__attackchain(obj/item/O, mob/user, params)
+/mob/living/simple_animal/hostile/asteroid/gutlunch/item_interaction(mob/living/user, obj/item/O, list/modifiers)
 	if(stat == CONSCIOUS && istype(O, /obj/item/reagent_containers/glass))
 		udder.milkAnimal(O, user)
 		regenerate_icons()
-	else
-		return ..()
+		return ITEM_INTERACT_COMPLETE
 
 /mob/living/simple_animal/hostile/asteroid/gutlunch/CanAttack(atom/the_target) // Gutlunch-specific version of CanAttack to handle stupid stat_exclusive = true crap so we don't have to do it for literally every single simple_animal/hostile except the two that spawn in lavaland
 	if(isturf(the_target) || !the_target || the_target.type == /atom/movable/lighting_object) // bail out on invalids

code/modules/mob/living/simple_animal/hostile/mushroom.dm

@@ -151,17 +151,21 @@
 		src.visible_message("<span class='notice'>[src] was bruised!</span>")
 		bruised = 1
 
-/mob/living/simple_animal/hostile/mushroom/attackby__legacy__attackchain(obj/item/I as obj, mob/user as mob, params)
+/mob/living/simple_animal/hostile/mushroom/item_interaction(mob/living/user, obj/item/I, list/modifiers)
 	if(istype(I, /obj/item/food/grown/mushroom))
 		if(stat == DEAD && !recovery_cooldown)
 			Recover()
 			qdel(I)
 		else
 			to_chat(user, "<span class='notice'>[src] won't eat it!</span>")
-		return
-	if(I.force)
+		return ITEM_INTERACT_COMPLETE
+
+/mob/living/simple_animal/hostile/mushroom/attacked_by(obj/item/attacker, mob/living/user)
+	if(..())
+		return FINISH_ATTACK
+
+	if(attacker.force)
 		Bruise()
-	..()
 
 /mob/living/simple_animal/hostile/mushroom/attack_hand(mob/living/carbon/human/M as mob)
 	..()

code/modules/mob/living/simple_animal/hostile/syndicate_mobs.dm

@@ -61,7 +61,10 @@
 	var/melee_block_chance = 20
 	var/ranged_block_chance = 35
 
-/mob/living/simple_animal/hostile/syndicate/melee/attackby__legacy__attackchain(obj/item/O as obj, mob/user as mob, params)
+/mob/living/simple_animal/hostile/syndicate/melee/attack_by(obj/item/O, mob/living/user, params)
+	if(..())
+		return FINISH_ATTACK
+
 	user.changeNext_move(CLICK_CD_MELEE)
 	user.do_attack_animation(src)
 	if(O.force)
@@ -81,6 +84,7 @@
 		to_chat(usr, "<span class='warning'>This weapon is ineffective, it does no damage.</span>")
 		visible_message("<span class='warning'>[user] gently taps [src] with [O].</span>")
 
+	return FINISH_ATTACK
 
 /mob/living/simple_animal/hostile/syndicate/melee/bullet_act(obj/item/projectile/Proj)
 	if(!Proj)

code/modules/mob/living/simple_animal/parrot.dm

@@ -177,19 +177,19 @@
 	return
 
 //Mobs with objects
-/mob/living/simple_animal/parrot/attackby__legacy__attackchain(obj/item/O, mob/user, params)
-	..()
-	if(stat == CONSCIOUS && !client && !istype(O, /obj/item/stack/medical))
-		if(O.force)
-			if(parrot_state == PARROT_PERCH)
-				parrot_sleep_dur = parrot_sleep_max //Reset it's sleep timer if it was perched
+/mob/living/simple_animal/parrot/attacked_by(obj/item/O, mob/living/user)
+	if(..())
+		return FINISH_ATTACK
 
-			parrot_interest = user
-			parrot_state = PARROT_SWOOP|PARROT_FLEE
-			icon_state = "parrot_fly"
-			ADD_TRAIT(src, TRAIT_FLYING, INNATE_TRAIT)
-			drop_held_item(FALSE)
-	return
+	if(O.force)
+		if(parrot_state == PARROT_PERCH)
+			parrot_sleep_dur = parrot_sleep_max //Reset it's sleep timer if it was perched
+
+		parrot_interest = user
+		parrot_state = PARROT_SWOOP|PARROT_FLEE
+		icon_state = "parrot_fly"
+		ADD_TRAIT(src, TRAIT_FLYING, INNATE_TRAIT)
+		drop_held_item(FALSE)
 
 //Bullets
 /mob/living/simple_animal/parrot/bullet_act(obj/item/projectile/P)

code/modules/mob/living/simple_animal/posessed_object.dm

@@ -173,12 +173,13 @@
 	set_opacity(possessed_item.opacity)
 	return ..(NONE)
 
-/mob/living/simple_animal/possessed_object/attackby__legacy__attackchain(obj/item/O, mob/living/user)
-	. = ..()
+/mob/living/simple_animal/possessed_object/item_interaction(mob/living/user, obj/item/O, list/modifiers)
 	if(istype(O, /obj/item/nullrod))
 		visible_message("<span type='notice'>[O] dispels the spooky aura!</span>")
 		death()
 
+		return ITEM_INTERACT_COMPLETE
+
 /mob/living/simple_animal/possessed_object/throw_impact(atom/hit_atom, throwingdatum)
 	//Don't call parent here as the mob isn't doing the hitting, technically
 	return possessed_item.throw_impact(hit_atom, throwingdatum)

code/modules/mob/living/simple_animal/shade.dm

@@ -33,12 +33,11 @@
 	initial_traits = list(TRAIT_FLYING, TRAIT_SHOCKIMMUNE)
 	var/holy = FALSE
 
-/mob/living/simple_animal/shade/attackby__legacy__attackchain(obj/item/O, mob/user)  //Marker -Agouri
+/mob/living/simple_animal/shade/item_interaction(mob/living/user, obj/item/O, list/modifiers)
 	if(istype(O, /obj/item/soulstone))
 		var/obj/item/soulstone/SS = O
 		SS.transfer_soul("SHADE", src, user)
-	else
-		..()
+		return ITEM_INTERACT_COMPLETE
 
 /mob/living/simple_animal/shade/Process_Spacemove(movement_dir = 0, continuous_move = FALSE)
 	return TRUE

code/modules/mob/living/simple_animal/slime/slime_mob.dm

@@ -356,35 +356,39 @@
 		discipline_slime(M)
 
 
-
-/mob/living/simple_animal/slime/attackby__legacy__attackchain(obj/item/I, mob/living/user, params)
+/mob/living/simple_animal/slime/item_interaction(mob/living/user, obj/item/I, list/modifiers)
 	if(stat == DEAD && length(surgeries))
 		if(user.a_intent == INTENT_HELP || user.a_intent == INTENT_DISARM)
 			for(var/datum/surgery/S in surgeries)
 				if(S.next_step(user, src))
-					return 1
+					return ITEM_INTERACT_COMPLETE
 	if(istype(I, /obj/item/stack/sheet/mineral/plasma) && stat == CONSCIOUS) //Let's you feed slimes plasma.
 		to_chat(user, "<span class='notice'>You feed the slime the plasma. It chirps happily.</span>")
 		var/obj/item/stack/sheet/mineral/plasma/S = I
 		S.use(1)
 		discipline_slime(user)
-		return
+		return ITEM_INTERACT_COMPLETE
 	if(I.force > 0)
 		attacked += 10
 		if(prob(25))
 			user.do_attack_animation(src)
 			user.changeNext_move(CLICK_CD_MELEE)
 			to_chat(user, "<span class='danger'>[I] passes right through [src]!</span>")
-			return
+			return ITEM_INTERACT_COMPLETE
 		if(Discipline && prob(50)) // wow, buddy, why am I getting attacked??
 			Discipline = 0
+			return ITEM_INTERACT_COMPLETE
+
+/mob/living/simple_animal/slime/attacked_by(obj/item/I, mob/living/user)
+	if(..())
+		return FINISH_ATTACK
+
 	if(I.force >= 3)
 		var/force_effect = 2 * I.force
 		if(is_adult)
 			force_effect = round(I.force / 2)
 		if(prob(10 + force_effect))
 			discipline_slime(user)
-	..()
 
 /mob/living/simple_animal/slime/water_act(volume, temperature, source, method = REAGENT_TOUCH)
 	. = ..()

code/modules/mob/mob_holder.dm

@@ -27,7 +27,7 @@
 
 /obj/item/holder/attackby__legacy__attackchain(obj/item/W as obj, mob/user as mob, params)
 	for(var/mob/M in src.contents)
-		M.attackby__legacy__attackchain(W,user, params)
+		M.attack_by(W, user, params)
 
 /obj/item/holder/proc/show_message(message, m_type, chat_message_type)
 	for(var/mob/living/M in contents)

code/modules/mob/mob_vars.dm

@@ -256,3 +256,5 @@
 	/// Does this mob speak OOC?
 	/// Controls whether they can say some symbols.
 	var/speaks_ooc = FALSE
+
+	new_attack_chain = TRUE