Moves yet more things from attackby() to item_interaction() (#96672)

## About The Pull Request

20 files converted, that last one's just to make the return value
explicit. The syndicate bomb `attackby()`'s only half converted, because
half of it was actually meant for `attackby()`.

## Why It's Good For The Game

only like, 250 files to go. Slow and steady.

## Changelog
🆑

code: 20 files have been converted from attackby() to item_interaction()

/🆑

code/game/machinery/bank_machine.dm

@@ -43,27 +43,28 @@
 	synced_bank_account = null
 	return ..()
 
-/obj/machinery/computer/bank_machine/attackby(obj/item/weapon, mob/user, list/modifiers, list/attack_modifiers)
+/obj/machinery/computer/bank_machine/item_interaction(mob/living/user, obj/item/tool, list/modifiers)
 	var/value = 0
-	if(istype(weapon, /obj/item/stack/spacecash))
-		var/obj/item/stack/spacecash/inserted_cash = weapon
+	if(istype(tool, /obj/item/stack/spacecash))
+		var/obj/item/stack/spacecash/inserted_cash = tool
 		value = inserted_cash.value * inserted_cash.amount
-	else if(istype(weapon, /obj/item/holochip))
-		var/obj/item/holochip/inserted_holochip = weapon
+	else if(istype(tool, /obj/item/holochip))
+		var/obj/item/holochip/inserted_holochip = tool
 		value = inserted_holochip.credits
-	else if(istype(weapon, /obj/item/coin))
-		var/obj/item/coin/inserted_coin = weapon
+	else if(istype(tool, /obj/item/coin))
+		var/obj/item/coin/inserted_coin = tool
 		value = inserted_coin.value
-	else if(istype(weapon, /obj/item/poker_chip))
-		var/obj/item/poker_chip/inserted_chip = weapon
+	else if(istype(tool, /obj/item/poker_chip))
+		var/obj/item/poker_chip/inserted_chip = tool
 		value = inserted_chip.get_item_credit_value()
-	if(value)
-		if(synced_bank_account)
-			synced_bank_account.adjust_money(value)
-			say("[MONEY_NAME_CAPITALIZED] deposited! The [synced_bank_account.account_holder] is now [synced_bank_account.account_balance] [MONEY_SYMBOL].")
-		qdel(weapon)
-		return
-	return ..()
+	if(!value)
+		return NONE
+	if(synced_bank_account)
+		synced_bank_account.adjust_money(value)
+		say("[MONEY_NAME_CAPITALIZED] deposited! The [synced_bank_account.account_holder] is now [synced_bank_account.account_balance] [MONEY_SYMBOL].")
+	qdel(tool)
+	return ITEM_INTERACT_SUCCESS
+
 
 /obj/machinery/computer/bank_machine/process(seconds_per_tick)
 	. = ..()

code/game/machinery/barsigns.dm

@@ -152,35 +152,35 @@ MAPPING_DIRECTIONAL_HELPERS(/obj/machinery/barsign, 32)
 	deconstruct(disassembled = TRUE)
 	return ITEM_INTERACT_SUCCESS
 
-/obj/machinery/barsign/attackby(obj/item/attacking_item, mob/user)
+/obj/machinery/barsign/item_interaction(mob/living/user, obj/item/tool, list/modifiers)
 
-	if(istype(attacking_item, /obj/item/blueprints) && !change_area_name)
+	if(istype(tool, /obj/item/blueprints) && !change_area_name)
 		if(!panel_open)
 			balloon_alert(user, "open the panel first!")
-			return TRUE
+			return ITEM_INTERACT_BLOCKING
 
 		change_area_name = TRUE
 		balloon_alert(user, "sign registered")
-		return TRUE
+		return ITEM_INTERACT_SUCCESS
 
-	if(istype(attacking_item, /obj/item/stack/cable_coil) && panel_open)
-		var/obj/item/stack/cable_coil/wire = attacking_item
+	if(istype(tool, /obj/item/stack/cable_coil) && panel_open)
+		var/obj/item/stack/cable_coil/wire = tool
 
 		if(atom_integrity >= max_integrity)
 			balloon_alert(user, "doesn't need repairs!")
-			return TRUE
+			return ITEM_INTERACT_BLOCKING
 
 		if(!wire.use(2))
 			balloon_alert(user, "need two cables!")
-			return TRUE
+			return ITEM_INTERACT_BLOCKING
 
 		balloon_alert(user, "repaired")
 		atom_integrity = max_integrity
 		set_machine_stat(machine_stat & ~BROKEN)
 		update_appearance()
-		return TRUE
+		return ITEM_INTERACT_SUCCESS
 
-	return ..()
+	return NONE
 
 /obj/machinery/barsign/emp_act(severity)
 	. = ..()

code/game/machinery/big_manipulator/big_manipulator.dm

@@ -288,6 +288,18 @@
 		SStgui.update_uis(src)
 		return ITEM_INTERACT_SUCCESS
 
+	if(isidcard(tool))
+		if(!id_lock)
+			id_lock = WEAKREF(tool)
+			balloon_alert(user, "successfully locked")
+			return ITEM_INTERACT_SUCCESS
+		if(tool != id_lock.resolve())
+			balloon_alert(user, "locked by another id")
+			return ITEM_INTERACT_BLOCKING
+		id_lock = null
+		balloon_alert(user, "successfully unlocked")
+		return ITEM_INTERACT_SUCCESS
+
 	if(!panel_open || !is_wire_tool(tool))
 		return NONE
 	wires.interact(user)
@@ -348,23 +360,6 @@
 		y_add = 32 + manipulator_arm.calculate_item_offset(FALSE, pixels_to_offset = 16)
 	)
 
-/obj/machinery/big_manipulator/attackby(obj/item/some_item, mob/user, params)
-	. = ..()
-	if(!isidcard(some_item))
-		return
-
-	var/obj/item/card/id/clicked_by_this_id = some_item
-
-	if(!id_lock)
-		id_lock = WEAKREF(clicked_by_this_id)
-		balloon_alert(user, "successfully locked")
-		return
-	var/obj/item/card/id/resolve_id = id_lock.resolve()
-	if(clicked_by_this_id != resolve_id)
-		balloon_alert(user, "locked by another id")
-		return
-	id_lock = null
-	balloon_alert(user, "successfully unlocked")
 
 /// Attaching the arm effect to the core.
 /obj/machinery/big_manipulator/proc/create_manipulator_arm()

code/game/machinery/computer/communications.dm

@@ -110,11 +110,11 @@
 		return TRUE
 	return authenticated
 
-/obj/machinery/computer/communications/attackby(obj/I, mob/user, list/modifiers, list/attack_modifiers)
-	if(isidcard(I))
-		attack_hand(user)
-	else
-		return ..()
+/obj/machinery/computer/communications/item_interaction(mob/living/user, obj/item/tool, list/modifiers)
+	if(!isidcard(tool))
+		return NONE
+	attack_hand(user)
+	return ITEM_INTERACT_SUCCESS
 
 /obj/machinery/computer/communications/emag_act(mob/user, obj/item/card/emag/emag_card)
 	if(istype(emag_card, /obj/item/card/emag/battlecruiser))

code/game/machinery/computer/dna_console.dm

@@ -181,53 +181,53 @@
 		genetic_damage_pulse()
 		return
 
-/obj/machinery/computer/dna_console/attackby(obj/item/item, mob/user, list/modifiers, list/attack_modifiers)
+/obj/machinery/computer/dna_console/item_interaction(mob/living/user, obj/item/tool, list/modifiers)
 	// Store chromosomes in the console if there's room
-	if (istype(item, /obj/item/chromosome))
-		item.forceMove(src)
-		stored_chromosomes += item
-		to_chat(user, span_notice("You insert [item]."))
-		return
+	if (istype(tool, /obj/item/chromosome))
+		tool.forceMove(src)
+		stored_chromosomes += tool
+		to_chat(user, span_notice("You insert [tool]."))
+		return ITEM_INTERACT_SUCCESS
 
 	// Insert data disk if console disk slot is empty
 	// Swap data disk if there is one already a disk in the console
-	if (istype(item, /obj/item/disk/data)) //INSERT SOME DISKETTES
+	if (istype(tool, /obj/item/disk/data)) //INSERT SOME DISKETTES
 		// Insert disk into DNA Console
-		if (!user.transferItemToLoc(item,src))
-			return
+		if (!user.transferItemToLoc(tool,src))
+			return ITEM_INTERACT_BLOCKING
 		// If insertion was successful and there's already a diskette in the console, eject the old one.
 		if(diskette)
 			eject_disk(user)
 		// Set the new diskette.
-		diskette = item
-		to_chat(user, span_notice("You insert [item]."))
-		return
+		diskette = tool
+		to_chat(user, span_notice("You insert [tool]."))
+		return ITEM_INTERACT_SUCCESS
 
 	// Recycle non-activator used injectors
 	// Turn activator used injectors (aka research injectors) to chromosomes
-	if(istype(item, /obj/item/dnainjector/activator))
-		var/obj/item/dnainjector/activator/activator = item
-		if(activator.used)
-			if(activator.research && activator.filled)
-				if(prob(60))
-					var/c_typepath = generate_chromosome()
-					var/obj/item/chromosome/CM = new c_typepath (src)
-					stored_chromosomes += CM
-					to_chat(user,span_notice("[capitalize(CM.name)] added to storage."))
-				else
-					to_chat(user, span_notice("There was not enough genetic data to extract a viable chromosome."))
-			if(activator.crispr_charge)
-				crispr_charges++
-				to_chat(user, span_notice("CRISPR charge added."))
-			qdel(item)
-			to_chat(user,span_notice("Recycled [item]."))
-			return
-		else
+	if(istype(tool, /obj/item/dnainjector/activator))
+		var/obj/item/dnainjector/activator/activator = tool
+		if(!activator.used)
 			//recycle unused activators
-			qdel(item)
-			to_chat(user, span_notice("Recycled unused [item]."))
-			return
-	return ..()
+			qdel(tool)
+			to_chat(user, span_notice("Recycled unused [tool]."))
+			return ITEM_INTERACT_SUCCESS
+		if(activator.research && activator.filled)
+			if(prob(60))
+				var/c_typepath = generate_chromosome()
+				var/obj/item/chromosome/CM = new c_typepath (src)
+				stored_chromosomes += CM
+				to_chat(user,span_notice("[capitalize(CM.name)] added to storage."))
+			else
+				to_chat(user, span_notice("There was not enough genetic data to extract a viable chromosome."))
+		if(activator.crispr_charge)
+			crispr_charges++
+			to_chat(user, span_notice("CRISPR charge added."))
+		qdel(tool)
+		to_chat(user,span_notice("Recycled [tool]."))
+		return ITEM_INTERACT_SUCCESS
+
+	return NONE
 
 /obj/machinery/computer/dna_console/multitool_act(mob/living/user, obj/item/multitool/tool)
 	if(!QDELETED(tool.buffer) && istype(tool.buffer, /datum/techweb))

code/game/machinery/computer/orders/order_computer/mining_order.dm

@@ -102,17 +102,17 @@
 	. = ..()
 	. += span_notice("There's [points] point\s on the card.")
 
-/obj/item/card/mining_point_card/attackby(obj/item/attacking_item, mob/user, list/modifiers, list/attack_modifiers)
-	if(!isidcard(attacking_item))
-		return ..()
-	var/obj/item/card/id/attacking_id = attacking_item
+/obj/item/card/mining_point_card/item_interaction(mob/living/user, obj/item/tool, list/modifiers)
+	if(!isidcard(tool))
+		return NONE
+	var/obj/item/card/id/attacking_id = tool
 	balloon_alert(user, "starting transfer")
 	var/point_movement = tgui_alert(user, "To ID (from card) or to card (from ID)?", "Mining Points Transfer", list(TO_USER_ID, TO_POINT_CARD))
 	if(!point_movement)
-		return
+		return ITEM_INTERACT_BLOCKING
 	var/amount = tgui_input_number(user, "How much do you want to transfer? ID Balance: [attacking_id.registered_account.mining_points], Card Balance: [points]", "Transfer Points", min_value = 0, round_value = 1)
 	if(!amount)
-		return
+		return ITEM_INTERACT_BLOCKING
 	switch(point_movement)
 		if(TO_USER_ID)
 			if(amount > points)
@@ -120,12 +120,15 @@
 			attacking_id.registered_account.mining_points += amount
 			points -= amount
 			to_chat(user, span_notice("You transfer [amount] mining points from [src] to [attacking_id]."))
+			return ITEM_INTERACT_SUCCESS
 		if(TO_POINT_CARD)
 			if(amount > attacking_id.registered_account.mining_points)
 				amount = attacking_id.registered_account.mining_points
 			attacking_id.registered_account.mining_points -= amount
 			points += amount
 			to_chat(user, span_notice("You transfer [amount] mining points from [attacking_id] to [src]."))
+			return ITEM_INTERACT_SUCCESS
+	return NONE
 
 #undef TO_POINT_CARD
 #undef TO_USER_ID

code/game/machinery/computer/prisoner/_prisoner.dm

@@ -50,9 +50,8 @@
 	balloon_alert_to_viewers("id ejected")
 	playsound(src, 'sound/machines/terminal/terminal_insert_disc.ogg', 50, FALSE)
 
-/obj/machinery/computer/prisoner/attackby(obj/item/weapon, mob/user, list/modifiers, list/attack_modifiers)
-	if(istype(weapon, /obj/item/card/id/advanced/prisoner))
-		id_insert(user, weapon)
-		return TRUE
-
-	return ..()
+/obj/machinery/computer/prisoner/item_interaction(mob/living/user, obj/item/tool, list/modifiers)
+	if(!istype(tool, /obj/item/card/id/advanced/prisoner))
+		return NONE
+	id_insert(user, tool)
+	return ITEM_INTERACT_SUCCESS

code/game/machinery/defibrillator_mount.dm

@@ -85,18 +85,18 @@ MAPPING_DIRECTIONAL_HELPERS(/obj/machinery/defibrillator_mount, 28)
 		return
 	user.put_in_hands(defib.paddles)
 
-/obj/machinery/defibrillator_mount/attackby(obj/item/item, mob/living/user, list/modifiers, list/attack_modifiers)
-	if(istype(item, /obj/item/defibrillator))
+/obj/machinery/defibrillator_mount/item_interaction(mob/living/user, obj/item/tool, list/modifiers)
+	if(istype(tool, /obj/item/defibrillator))
 		if(defib)
 			to_chat(user, span_warning("There's already a defibrillator in [src]!"))
-			return
-		var/obj/item/defibrillator/new_defib = item
+			return ITEM_INTERACT_BLOCKING
+		var/obj/item/defibrillator/new_defib = tool
 		if(!new_defib.get_cell())
 			to_chat(user, span_warning("Only defibrilators containing a cell can be hooked up to [src]!"))
-			return
+			return ITEM_INTERACT_BLOCKING
 		if(HAS_TRAIT(new_defib, TRAIT_NODROP) || !user.transferItemToLoc(new_defib, src))
 			to_chat(user, span_warning("[new_defib] is stuck to your hand!"))
-			return
+			return ITEM_INTERACT_BLOCKING
 		user.visible_message(span_notice("[user] hooks up [new_defib] to [src]!"), \
 		span_notice("You press [new_defib] into the mount, and it clicks into place."))
 		playsound(src, 'sound/machines/click.ogg', 50, TRUE)
@@ -104,20 +104,27 @@ MAPPING_DIRECTIONAL_HELPERS(/obj/machinery/defibrillator_mount, 28)
 		defib = new_defib
 		begin_processing()
 		update_appearance()
-		return
-	else if(defib && item == defib.paddles)
-		defib.paddles.snap_back()
-		return
+		return ITEM_INTERACT_SUCCESS
 
-	if(!item.GetID() || (!allowed(user) && SSsecurity_level.get_current_level_as_number() < SEC_LEVEL_RED)) //anyone can toggle the clamps in red alert!
+	if(defib && tool == defib.paddles)
+		defib.paddles.snap_back()
+		return ITEM_INTERACT_SUCCESS
+
+	if(!tool.GetID())
+		return NONE
+
+	if((!allowed(user) && SSsecurity_level.get_current_level_as_number() < SEC_LEVEL_RED)) //anyone can toggle the clamps in red alert!
 		to_chat(user, span_warning("Insufficient access."))
-		return
+		return ITEM_INTERACT_BLOCKING
+
 	if(!defib)
 		to_chat(user, span_warning("You can't engage the clamps on a defibrillator that isn't there."))
-		return
+		return ITEM_INTERACT_BLOCKING
+
 	clamps_locked = !clamps_locked
 	to_chat(user, span_notice("Clamps [clamps_locked ? "" : "dis"]engaged."))
 	update_appearance()
+	return ITEM_INTERACT_SUCCESS
 
 /obj/machinery/defibrillator_mount/multitool_act(mob/living/user, obj/item/multitool)
 	..()

code/game/machinery/doors/airlock.dm

@@ -940,18 +940,17 @@
 
 /obj/machinery/door/airlock/wirecutter_act(mob/living/user, obj/item/tool)
 	if(panel_open && security_level == AIRLOCK_SECURITY_PLASTEEL)
-		. = ITEM_INTERACT_SUCCESS  // everything after this shouldn't result in attackby
 		if(hasPower() && shock(user, 60)) // Protective grille of wiring is electrified
-			return .
+			return ITEM_INTERACT_BLOCKING
 		to_chat(user, span_notice("You start cutting through the outer grille."))
 		if(!tool.use_tool(src, user, 10, volume=100))
-			return .
+			return ITEM_INTERACT_BLOCKING
 		if(!panel_open)  // double check it wasn't closed while we were trying to snip
-			return .
+			return ITEM_INTERACT_BLOCKING
 		user.visible_message(span_notice("[user] cut through [src]'s outer grille."),
 							span_notice("You cut through [src]'s outer grille."))
 		security_level = AIRLOCK_SECURITY_PLASTEEL_O
-		return .
+		return ITEM_INTERACT_SUCCESS
 	if(note)
 		if(IsReachableBy(user))
 			user.visible_message(span_notice("[user] cuts down [note] from [src]."), span_notice("You remove [note] from [src]."))
@@ -1073,85 +1072,98 @@
 	return ITEM_INTERACT_SUCCESS
 
 /obj/machinery/door/airlock/proc/try_reinforce(mob/user, obj/item/stack/sheet/material, amt_required, new_security_level)
+	if(!HAS_SILICON_ACCESS(user) && isElectrified() && shock(user, 75))
+		return ITEM_INTERACT_BLOCKING
 	if(material.get_amount() < amt_required)
 		to_chat(user, span_warning("You need at least [amt_required] sheets of [material] to reinforce [src]."))
-		return FALSE
+		return ITEM_INTERACT_BLOCKING
 	to_chat(user, span_notice("You start reinforcing [src]."))
 	if(!do_after(user, 2 SECONDS, src))
-		return FALSE
+		return ITEM_INTERACT_BLOCKING
 	if(!panel_open || !material.use(amt_required))
-		return FALSE
+		return ITEM_INTERACT_BLOCKING
 	user.visible_message(span_notice("[user] reinforces [src] with [material]."),
 						span_notice("You reinforce [src] with [material]."))
 	security_level = new_security_level
 	update_appearance()
-	return TRUE
+	return ITEM_INTERACT_SUCCESS
 
-/obj/machinery/door/airlock/attackby(obj/item/C, mob/user, list/modifiers, list/attack_modifiers)
-	if(!HAS_SILICON_ACCESS(user))
-		if(isElectrified() && (C.obj_flags & CONDUCTS_ELECTRICITY) && shock(user, 75))
-			return
+/obj/machinery/door/airlock/attacked_by(obj/item/attacking_item, mob/living/user, list/modifiers, list/attack_modifiers)
+	if(!HAS_SILICON_ACCESS(user) && isElectrified() && (attacking_item.obj_flags & CONDUCTS_ELECTRICITY) && shock(user, 75))
+		return ATTACK_FAILED
+	return ..()
+
+/obj/machinery/door/airlock/item_interaction(mob/living/user, obj/item/tool, list/modifiers)
 	add_fingerprint(user)
 
-	if(is_wire_tool(C) && panel_open)
+	if(is_wire_tool(tool) && panel_open)
 		attempt_wire_interaction(user)
-		return
-	else if(panel_open && security_level == AIRLOCK_SECURITY_NONE && istype(C, /obj/item/stack/sheet))
-		if(istype(C, /obj/item/stack/sheet/iron))
-			return try_reinforce(user, C, 2, AIRLOCK_SECURITY_IRON)
+		return ITEM_INTERACT_SUCCESS
 
-		else if(istype(C, /obj/item/stack/sheet/plasteel))
-			if(!try_reinforce(user, C, 2, AIRLOCK_SECURITY_PLASTEEL))
-				return FALSE
+	if(panel_open && security_level == AIRLOCK_SECURITY_NONE && istype(tool, /obj/item/stack/sheet))
+		if(istype(tool, /obj/item/stack/sheet/iron))
+			return try_reinforce(user, tool, 2, AIRLOCK_SECURITY_IRON)
+
+		if(istype(tool, /obj/item/stack/sheet/plasteel))
+			if(try_reinforce(user, tool, 2, AIRLOCK_SECURITY_PLASTEEL) & ITEM_INTERACT_BLOCKING)
+				return ITEM_INTERACT_BLOCKING
 			modify_max_integrity(max_integrity * AIRLOCK_INTEGRITY_MULTIPLIER)
 			damage_deflection = AIRLOCK_DAMAGE_DEFLECTION_R
 			update_appearance()
-			return TRUE
+			return ITEM_INTERACT_SUCCESS
 
-	else if(istype(C, /obj/item/pai_cable))
-		var/obj/item/pai_cable/cable = C
+		return NONE
+
+	if(istype(tool, /obj/item/pai_cable))
+		var/obj/item/pai_cable/cable = tool
 		cable.plugin(src, user)
-	else if(istype(C, /obj/item/airlock_painter))
-		change_paintjob(C, user)
-	else if(istype(C, /obj/item/door_seal)) //adding the seal
-		var/obj/item/door_seal/airlockseal = C
+		return ITEM_INTERACT_SUCCESS
+
+	if(istype(tool, /obj/item/airlock_painter))
+		change_paintjob(tool, user)
+		return ITEM_INTERACT_SUCCESS
+
+	if(istype(tool, /obj/item/door_seal)) //adding the seal
+		var/obj/item/door_seal/airlockseal = tool
 		if(!density)
 			to_chat(user, span_warning("[src] must be closed before you can seal it!"))
-			return
+			return ITEM_INTERACT_BLOCKING
 		if(seal)
 			to_chat(user, span_warning("[src] has already been sealed!"))
-			return
+			return ITEM_INTERACT_BLOCKING
 		user.visible_message(span_notice("[user] begins sealing [src]."), span_notice("You begin sealing [src]."))
 		playsound(src, 'sound/items/tools/jaws_pry.ogg', 30, TRUE)
 		if(!do_after(user, airlockseal.seal_time, target = src))
-			return
+			return ITEM_INTERACT_BLOCKING
 		if(!density)
 			to_chat(user, span_warning("[src] must be closed before you can seal it!"))
-			return
+			return ITEM_INTERACT_BLOCKING
 		if(seal)
 			to_chat(user, span_warning("[src] has already been sealed!"))
-			return
+			return ITEM_INTERACT_BLOCKING
 		if(!user.transferItemToLoc(airlockseal, src))
 			to_chat(user, span_warning("For some reason, you can't attach [airlockseal]!"))
-			return
+			return ITEM_INTERACT_BLOCKING
 		playsound(src, 'sound/machines/airlock/airlockforced.ogg', 30, TRUE)
 		user.visible_message(span_notice("[user] finishes sealing [src]."), span_notice("You finish sealing [src]."))
 		seal = airlockseal
 		modify_max_integrity(max_integrity * AIRLOCK_SEAL_MULTIPLIER)
 		update_appearance()
+		return ITEM_INTERACT_SUCCESS
 
-	else if(istype(C, /obj/item/paper) || istype(C, /obj/item/photo))
+	if(istype(tool, /obj/item/paper) || istype(tool, /obj/item/photo))
 		if(note)
 			to_chat(user, span_warning("There's already something pinned to this airlock! Use wirecutters to remove it."))
-			return
-		if(!user.transferItemToLoc(C, src))
-			to_chat(user, span_warning("For some reason, you can't attach [C]!"))
-			return
-		user.visible_message(span_notice("[user] pins [C] to [src]."), span_notice("You pin [C] to [src]."))
-		note = C
+			return ITEM_INTERACT_BLOCKING
+		if(!user.transferItemToLoc(tool, src))
+			to_chat(user, span_warning("For some reason, you can't attach [tool]!"))
+			return ITEM_INTERACT_BLOCKING
+		user.visible_message(span_notice("[user] pins [tool] to [src]."), span_notice("You pin [tool] to [src]."))
+		note = tool
 		update_appearance()
-	else
-		return ..()
+		return ITEM_INTERACT_SUCCESS
+
+	return NONE
 
 
 /obj/machinery/door/airlock/try_to_weld(obj/item/weldingtool/W, mob/living/user)

code/game/machinery/doors/door.dm

@@ -331,13 +331,13 @@
 /obj/machinery/door/proc/try_to_activate_door(mob/user, access_bypass = FALSE, bumped = FALSE)
 	add_fingerprint(user)
 	if(operating || (obj_flags & EMAGGED))
-		return
+		return FALSE
 
 	if(!bumped && !can_open_with_hands)
-		return
+		return FALSE
 
 	if(elevator_mode && elevator_status != LIFT_PLATFORM_UNLOCKED)
-		return
+		return FALSE
 
 	// note: if the ID wire is cut no ID cards are checked at all! (This is intentional!)
 	if(access_bypass || (requiresID() && user_can_activate_door(user)))
@@ -347,8 +347,9 @@
 			close()
 		return TRUE
 
-	else if(!operating && density)
+	if(!operating && density)
 		run_animation(DOOR_DENY_ANIMATION)
+	return FALSE
 
 /// Used in try_to_activate_door
 /obj/machinery/door/proc/user_can_activate_door(mob/user)
@@ -448,20 +449,27 @@
 /obj/machinery/door/try_to_crowbar_secondary(obj/item/acting_object, mob/user)
 	try_to_crowbar(null, user, FALSE)
 
-/obj/machinery/door/attackby(obj/item/weapon, mob/living/user, list/modifiers, list/attack_modifiers)
-	if(istype(weapon, /obj/item/access_key))
-		var/obj/item/access_key/key = weapon
-		return key.attempt_open_door(user, src)
-	else if(!user.combat_mode && istype(weapon, /obj/item/fireaxe))
-		try_to_crowbar(weapon, user, FALSE)
-		return TRUE
-	else if(weapon.item_flags & NOBLUDGEON || user.combat_mode)
-		return ..()
-	else if(!user.combat_mode && istype(weapon, /obj/item/stack/sheet/mineral/wood))
-		return ..() // we need this so our can_barricade element can be called using COMSIG_ATOM_ATTACKBY
-	else if(try_to_activate_door(user))
-		return TRUE
-	return ..()
+/obj/machinery/door/item_interaction(mob/living/user, obj/item/tool, list/modifiers)
+	if(istype(tool, /obj/item/access_key))
+		var/obj/item/access_key/key = tool
+		if(!key.attempt_open_door(user, src))
+			return ITEM_INTERACT_BLOCKING
+		return ITEM_INTERACT_SUCCESS
+
+	if(!user.combat_mode && istype(tool, /obj/item/fireaxe))
+		try_to_crowbar(tool, user, FALSE)
+		return ITEM_INTERACT_SUCCESS
+
+	if(tool.item_flags & NOBLUDGEON || user.combat_mode)
+		return NONE
+
+	if(istype(tool, /obj/item/stack/sheet/mineral/wood))
+		return NONE // we need this so our can_barricade element can be called using COMSIG_ATOM_ATTACKBY
+
+	if(try_to_activate_door(user))
+		return ITEM_INTERACT_SUCCESS
+
+	return NONE
 
 /obj/machinery/door/item_interaction_secondary(mob/living/user, obj/item/tool, list/modifiers)
 	// allows you to crowbar doors while in combat mode

code/game/machinery/doors/firedoor.dm

@@ -836,114 +836,128 @@
 	icon_state = "[base_icon_state][constructionStep]"
 	return ..()
 
-/obj/structure/firelock_frame/attackby(obj/item/attacking_object, mob/user)
+/obj/structure/firelock_frame/item_interaction(mob/living/user, obj/item/tool, list/modifiers)
 	switch(constructionStep)
 		if(CONSTRUCTION_PANEL_OPEN)
-			if(attacking_object.tool_behaviour == TOOL_CROWBAR)
-				attacking_object.play_tool_sound(src)
-				user.visible_message(span_notice("[user] begins removing the circuit board from [src]..."), \
-					span_notice("You begin prying out the circuit board from [src]..."))
-				if(!attacking_object.use_tool(src, user, DEFAULT_STEP_TIME))
-					return
-				if(constructionStep != CONSTRUCTION_PANEL_OPEN)
-					return
-				playsound(get_turf(src), 'sound/items/deconstruct.ogg', 50, TRUE)
-				user.visible_message(span_notice("[user] removes [src]'s circuit board."), \
-					span_notice("You remove the circuit board from [src]."))
-				new /obj/item/electronics/firelock(drop_location())
-				constructionStep = CONSTRUCTION_NO_CIRCUIT
-				update_appearance()
-				return
-			if(attacking_object.tool_behaviour == TOOL_WRENCH)
-				if(locate(/obj/machinery/door/firedoor) in get_turf(src))
-					to_chat(user, span_warning("There's already a firelock there."))
-					return
-				attacking_object.play_tool_sound(src)
-				user.visible_message(span_notice("[user] starts bolting down [src]..."), \
-					span_notice("You begin bolting [src]..."))
-				if(!attacking_object.use_tool(src, user, DEFAULT_STEP_TIME))
-					return
-				if(locate(/obj/machinery/door/firedoor) in get_turf(src))
-					return
-				user.visible_message(span_notice("[user] finishes the firelock."), \
-					span_notice("You finish the firelock."))
-				playsound(get_turf(src), 'sound/items/deconstruct.ogg', 50, TRUE)
-				if(reinforced)
-					new /obj/machinery/door/firedoor/heavy(get_turf(src))
-				else if(directional)
-					var/obj/machinery/door/firedoor/border_only/new_firedoor = new /obj/machinery/door/firedoor/border_only(get_turf(src))
-					new_firedoor.setDir(dir)
-					new_firedoor.adjust_lights_starting_offset()
-				else
-					new /obj/machinery/door/firedoor(get_turf(src))
-				qdel(src)
-				return
-			if(istype(attacking_object, /obj/item/stack/sheet/plasteel))
-				if(directional)
-					to_chat(user, span_warning("[src] can not be reinforced."))
-					return
-				var/obj/item/stack/sheet/plasteel/plasteel_sheet = attacking_object
-				if(reinforced)
-					to_chat(user, span_warning("[src] is already reinforced."))
-					return
-				if(plasteel_sheet.get_amount() < 2)
-					to_chat(user, span_warning("You need more plasteel to reinforce [src]."))
-					return
-				user.visible_message(span_notice("[user] begins reinforcing [src]..."), \
-					span_notice("You begin reinforcing [src]..."))
-				playsound(get_turf(src), 'sound/items/deconstruct.ogg', 50, TRUE)
-				if(do_after(user, DEFAULT_STEP_TIME, target = src))
-					if(constructionStep != CONSTRUCTION_PANEL_OPEN || reinforced || plasteel_sheet.get_amount() < 2 || !plasteel_sheet)
-						return
-					user.visible_message(span_notice("[user] reinforces [src]."), \
-						span_notice("You reinforce [src]."))
-					playsound(get_turf(src), 'sound/items/deconstruct.ogg', 50, TRUE)
-					plasteel_sheet.use(2)
-					reinforced = 1
-				return
+			if(!istype(tool, /obj/item/stack/sheet/plasteel))
+				return NONE
+			if(directional)
+				to_chat(user, span_warning("[src] can not be reinforced."))
+				return ITEM_INTERACT_BLOCKING
+			var/obj/item/stack/sheet/plasteel/plasteel_sheet = tool
+			if(reinforced)
+				to_chat(user, span_warning("[src] is already reinforced."))
+				return ITEM_INTERACT_BLOCKING
+			if(plasteel_sheet.get_amount() < 2)
+				to_chat(user, span_warning("You need more plasteel to reinforce [src]."))
+				return ITEM_INTERACT_BLOCKING
+			user.visible_message(span_notice("[user] begins reinforcing [src]..."), \
+								span_notice("You begin reinforcing [src]..."))
+			playsound(get_turf(src), 'sound/items/deconstruct.ogg', 50, TRUE)
+			if(!do_after(user, DEFAULT_STEP_TIME, target = src))
+				return ITEM_INTERACT_BLOCKING
+			if(constructionStep != CONSTRUCTION_PANEL_OPEN || reinforced || plasteel_sheet.get_amount() < 2 || !plasteel_sheet)
+				return ITEM_INTERACT_BLOCKING
+			user.visible_message(span_notice("[user] reinforces [src]."), \
+								span_notice("You reinforce [src]."))
+			playsound(get_turf(src), 'sound/items/deconstruct.ogg', 50, TRUE)
+			plasteel_sheet.use(2)
+			reinforced = 1
+			return ITEM_INTERACT_SUCCESS
+
 		if(CONSTRUCTION_NO_CIRCUIT)
-			if(istype(attacking_object, /obj/item/electronics/firelock))
-				user.visible_message(span_notice("[user] starts adding [attacking_object] to [src]..."), \
+			if(istype(tool, /obj/item/electronics/firelock))
+				user.visible_message(span_notice("[user] starts adding [tool] to [src]..."), \
 					span_notice("You begin adding a circuit board to [src]..."))
 				playsound(get_turf(src), 'sound/items/deconstruct.ogg', 50, TRUE)
 				if(!do_after(user, DEFAULT_STEP_TIME, target = src))
-					return
+					return ITEM_INTERACT_BLOCKING
 				if(constructionStep != CONSTRUCTION_NO_CIRCUIT)
-					return
-				qdel(attacking_object)
+					return ITEM_INTERACT_BLOCKING
+				qdel(tool)
 				user.visible_message(span_notice("[user] adds a circuit to [src]."), \
-					span_notice("You insert and secure [attacking_object]."))
+					span_notice("You insert and secure [tool]."))
 				playsound(get_turf(src), 'sound/items/deconstruct.ogg', 50, TRUE)
 				constructionStep = CONSTRUCTION_PANEL_OPEN
 				update_appearance()
-				return
-			if(attacking_object.tool_behaviour == TOOL_WELDER)
-				if(!attacking_object.tool_start_check(user, amount=1))
-					return
-				user.visible_message(span_notice("[user] begins cutting apart [src]'s frame..."), \
-					span_notice("You begin slicing [src] apart..."))
+				return ITEM_INTERACT_SUCCESS
 
-				if(attacking_object.use_tool(src, user, DEFAULT_STEP_TIME, volume=50))
-					if(constructionStep != CONSTRUCTION_NO_CIRCUIT)
-						return
-					user.visible_message(span_notice("[user] cuts apart [src]!"), \
-						span_notice("You cut [src] into metal."))
-					var/turf/targetloc = get_turf(src)
-					new /obj/item/stack/sheet/iron(targetloc, directional ? 2 : 3)
-					if(reinforced)
-						new /obj/item/stack/sheet/plasteel(targetloc, 2)
-					qdel(src)
-				return
-			if(istype(attacking_object, /obj/item/electroadaptive_pseudocircuit))
-				var/obj/item/electroadaptive_pseudocircuit/raspberrypi = attacking_object
+			if(istype(tool, /obj/item/electroadaptive_pseudocircuit))
+				var/obj/item/electroadaptive_pseudocircuit/raspberrypi = tool
 				if(!raspberrypi.adapt_circuit(user, circuit_cost = DEFAULT_STEP_TIME * 0.0005 * STANDARD_CELL_CHARGE))
-					return
+					return ITEM_INTERACT_BLOCKING
 				user.visible_message(span_notice("[user] fabricates a circuit and places it into [src]."), \
 				span_notice("You adapt a firelock circuit and slot it into the assembly."))
 				constructionStep = CONSTRUCTION_PANEL_OPEN
 				update_appearance()
-				return
-	return ..()
+				return ITEM_INTERACT_SUCCESS
+	return NONE
+
+/obj/structure/firelock_frame/crowbar_act(mob/living/user, obj/item/tool)
+	if(constructionStep != CONSTRUCTION_PANEL_OPEN)
+		return NONE
+	tool.play_tool_sound(src)
+	user.visible_message(span_notice("[user] begins removing the circuit board from [src]..."), \
+						span_notice("You begin prying out the circuit board from [src]..."))
+	if(!tool.use_tool(src, user, DEFAULT_STEP_TIME))
+		return ITEM_INTERACT_BLOCKING
+	if(constructionStep != CONSTRUCTION_PANEL_OPEN)
+		return ITEM_INTERACT_BLOCKING
+	playsound(get_turf(src), 'sound/items/deconstruct.ogg', 50, TRUE)
+	user.visible_message(span_notice("[user] removes [src]'s circuit board."), \
+						span_notice("You remove the circuit board from [src]."))
+	new /obj/item/electronics/firelock(drop_location())
+	constructionStep = CONSTRUCTION_NO_CIRCUIT
+	update_appearance()
+	return ITEM_INTERACT_SUCCESS
+
+/obj/structure/firelock_frame/wrench_act(mob/living/user, obj/item/tool)
+	if(constructionStep != CONSTRUCTION_PANEL_OPEN)
+		return NONE
+	if(locate(/obj/machinery/door/firedoor) in get_turf(src))
+		to_chat(user, span_warning("There's already a firelock there."))
+		return ITEM_INTERACT_BLOCKING
+	tool.play_tool_sound(src)
+	user.visible_message(span_notice("[user] starts bolting down [src]..."), \
+						span_notice("You begin bolting [src]..."))
+	if(!tool.use_tool(src, user, DEFAULT_STEP_TIME))
+		return ITEM_INTERACT_BLOCKING
+	if(locate(/obj/machinery/door/firedoor) in get_turf(src))
+		return ITEM_INTERACT_BLOCKING
+	user.visible_message(span_notice("[user] finishes the firelock."), \
+						span_notice("You finish the firelock."))
+	playsound(get_turf(src), 'sound/items/deconstruct.ogg', 50, TRUE)
+	if(reinforced)
+		new /obj/machinery/door/firedoor/heavy(get_turf(src))
+	else if(directional)
+		var/obj/machinery/door/firedoor/border_only/new_firedoor = new /obj/machinery/door/firedoor/border_only(get_turf(src))
+		new_firedoor.setDir(dir)
+		new_firedoor.adjust_lights_starting_offset()
+	else
+		new /obj/machinery/door/firedoor(get_turf(src))
+	qdel(src)
+	return ITEM_INTERACT_SUCCESS
+
+/obj/structure/firelock_frame/welder_act(mob/living/user, obj/item/tool)
+	if(constructionStep != CONSTRUCTION_NO_CIRCUIT)
+		return NONE
+	if(!tool.tool_start_check(user, amount=1))
+		return ITEM_INTERACT_BLOCKING
+	user.visible_message(span_notice("[user] begins cutting apart [src]'s frame..."), \
+		span_notice("You begin slicing [src] apart..."))
+
+	if(!tool.use_tool(src, user, DEFAULT_STEP_TIME, volume=50))
+		return ITEM_INTERACT_BLOCKING
+	if(constructionStep != CONSTRUCTION_NO_CIRCUIT)
+		return ITEM_INTERACT_BLOCKING
+	user.visible_message(span_notice("[user] cuts apart [src]!"), \
+		span_notice("You cut [src] into metal."))
+	var/turf/targetloc = get_turf(src)
+	new /obj/item/stack/sheet/iron(targetloc, directional ? 2 : 3)
+	if(reinforced)
+		new /obj/item/stack/sheet/plasteel(targetloc, 2)
+	qdel(src)
+	return ITEM_INTERACT_SUCCESS
 
 /obj/structure/firelock_frame/rcd_vals(mob/user, obj/item/construction/rcd/the_rcd)
 	if(the_rcd.mode == RCD_DECONSTRUCT)

code/game/machinery/flasher.dm

@@ -62,35 +62,45 @@ MAPPING_DIRECTIONAL_HELPERS(/obj/machinery/flasher, 26)
 	return ..()
 
 //Don't want to render prison breaks impossible
-/obj/machinery/flasher/attackby(obj/item/attacking_item, mob/user, list/modifiers, list/attack_modifiers)
+/obj/machinery/flasher/item_interaction(mob/living/user, obj/item/tool, list/modifiers)
 	add_fingerprint(user)
-	if (attacking_item.tool_behaviour == TOOL_WIRECUTTER)
-		if (bulb)
-			user.visible_message(span_notice("[user] begins to disconnect [src]'s flashbulb."), span_notice("You begin to disconnect [src]'s flashbulb..."))
-			if(attacking_item.use_tool(src, user, 30, volume=50) && bulb)
-				user.visible_message(span_notice("[user] disconnects [src]'s flashbulb!"), span_notice("You disconnect [src]'s flashbulb."))
-				bulb.forceMove(loc)
-				power_change()
 
-	else if (istype(attacking_item, /obj/item/assembly/flash/handheld))
-		if (!bulb)
-			if(!user.transferItemToLoc(attacking_item, src))
-				return
-			user.visible_message(span_notice("[user] installs [attacking_item] into [src]."), span_notice("You install [attacking_item] into [src]."))
-			power_change()
-		else
-			to_chat(user, span_warning("A flashbulb is already installed in [src]!"))
+	if (!istype(tool, /obj/item/assembly/flash/handheld))
+		return NONE
+	if (bulb)
+		to_chat(user, span_warning("A flashbulb is already installed in [src]!"))
+		return ITEM_INTERACT_BLOCKING
+	if(!user.transferItemToLoc(tool, src))
+		return ITEM_INTERACT_BLOCKING
+	user.visible_message(span_notice("[user] installs [tool] into [src]."), \
+						span_notice("You install [tool] into [src]."))
+	power_change()
+	return ITEM_INTERACT_SUCCESS
 
-	else if (attacking_item.tool_behaviour == TOOL_WRENCH)
-		if(!bulb)
-			to_chat(user, span_notice("You start unsecuring the flasher frame..."))
-			if(attacking_item.use_tool(src, user, 40, volume=50))
-				to_chat(user, span_notice("You unsecure the flasher frame."))
-				deconstruct(TRUE)
-		else
-			to_chat(user, span_warning("Remove a flashbulb from [src] first!"))
-	else
-		return ..()
+
+/obj/machinery/flasher/wirecutter_act(mob/living/user, obj/item/tool)
+	add_fingerprint(user)
+	if(!bulb)
+		return NONE
+	user.visible_message(span_notice("[user] begins to disconnect [src]'s flashbulb."), span_notice("You begin to disconnect [src]'s flashbulb..."))
+	if(!tool.use_tool(src, user, 30, volume=50) || !bulb)
+		return ITEM_INTERACT_BLOCKING
+	user.visible_message(span_notice("[user] disconnects [src]'s flashbulb!"), span_notice("You disconnect [src]'s flashbulb."))
+	bulb.forceMove(loc)
+	power_change()
+	return ITEM_INTERACT_SUCCESS
+
+/obj/machinery/flasher/wrench_act(mob/living/user, obj/item/tool)
+	add_fingerprint(user)
+	if(bulb)
+		to_chat(user, span_warning("Remove a flashbulb from [src] first!"))
+		return ITEM_INTERACT_BLOCKING
+	to_chat(user, span_notice("You start unsecuring the flasher frame..."))
+	if(!tool.use_tool(src, user, 40, volume=50))
+		return ITEM_INTERACT_BLOCKING
+	to_chat(user, span_notice("You unsecure the flasher frame."))
+	deconstruct(TRUE)
+	return ITEM_INTERACT_SUCCESS
 
 //Let the AI trigger them directly.
 /obj/machinery/flasher/attack_ai()
@@ -189,25 +199,22 @@ MAPPING_DIRECTIONAL_HELPERS(/obj/machinery/flasher, 26)
 	if(vname == NAMEOF(src, flash_range))
 		proximity_monitor?.set_range(flash_range)
 
-/obj/machinery/flasher/portable/attackby(obj/item/attacking_item, mob/user, list/modifiers, list/attack_modifiers)
-	if (attacking_item.tool_behaviour == TOOL_WRENCH)
-		attacking_item.play_tool_sound(src, 100)
+/obj/machinery/flasher/portable/wrench_act(mob/living/user, obj/item/tool)
+	tool.play_tool_sound(src, 100)
+	if (!anchored && !isinspace())
+		to_chat(user, span_notice("[src] is now secured."))
+		add_overlay("[base_icon_state]-s")
+		set_anchored(TRUE)
+		power_change()
+		proximity_monitor.set_range(flash_range)
+		return ITEM_INTERACT_SUCCESS
 
-		if (!anchored && !isinspace())
-			to_chat(user, span_notice("[src] is now secured."))
-			add_overlay("[base_icon_state]-s")
-			set_anchored(TRUE)
-			power_change()
-			proximity_monitor.set_range(flash_range)
-		else
-			to_chat(user, span_notice("[src] can now be moved."))
-			cut_overlays()
-			set_anchored(FALSE)
-			power_change()
-			proximity_monitor.set_range(0)
-
-	else
-		return ..()
+	to_chat(user, span_notice("[src] can now be moved."))
+	cut_overlays()
+	set_anchored(FALSE)
+	power_change()
+	proximity_monitor.set_range(0)
+	return ITEM_INTERACT_SUCCESS
 
 /obj/item/wallframe/flasher
 	name = "mounted flash frame"

code/game/machinery/launch_pad.dm

@@ -320,15 +320,16 @@
 			closed = TRUE
 			update_indicator()
 
-/obj/machinery/launchpad/briefcase/attackby(obj/item/item, mob/user, list/modifiers, list/attack_modifiers)
-	if(istype(item, /obj/item/launchpad_remote))
-		var/obj/item/launchpad_remote/launch = item
-		if(IS_WEAKREF_OF(src, launch.pad)) //do not attempt to link when already linked
-			return ..()
-		launch.pad = WEAKREF(src)
-		to_chat(user, span_notice("You link [src] to [launch]."))
-	else
-		return ..()
+/obj/machinery/launchpad/briefcase/item_interaction(mob/living/user, obj/item/tool, list/modifiers)
+	if(!istype(tool, /obj/item/launchpad_remote))
+		return NONE
+	var/obj/item/launchpad_remote/remote = tool
+	if(IS_WEAKREF_OF(src, remote.pad)) //do not attempt to link when already linked
+		return ITEM_INTERACT_BLOCKING
+	remote.pad = WEAKREF(src)
+	to_chat(user, span_notice("You link [src] to [remote]."))
+	return ITEM_INTERACT_SUCCESS
+
 
 /obj/item/launchpad_remote
 	name = "folder"

code/game/machinery/modular_shield.dm

@@ -144,13 +144,11 @@
 /obj/machinery/modular_shield_generator/crowbar_act(mob/living/user, obj/item/tool)
 	return default_deconstruction_crowbar(user, tool)
 
-/obj/machinery/modular_shield_generator/attackby(obj/item/W, mob/user, list/modifiers)
-
-	if(is_wire_tool(W) && panel_open)
-		wires.interact(user)
-		return TRUE
-
-	return ..()
+/obj/machinery/modular_shield_generator/item_interaction(mob/living/user, obj/item/tool, list/modifiers)
+	if(!panel_open || !is_wire_tool(tool))
+		return NONE
+	wires.interact(user)
+	return ITEM_INTERACT_SUCCESS
 
 /obj/machinery/modular_shield_generator/multitool_act(mob/living/user, obj/item/multitool/multi)
 	multi.set_buffer(src)

code/game/machinery/navbeacon.dm

@@ -119,24 +119,23 @@
 	. = ..()
 	icon_state = "[base_icon_state][panel_open]"
 
-/obj/machinery/navbeacon/attackby(obj/item/attacking_item, mob/user, list/modifiers, list/attack_modifiers)
+/obj/machinery/navbeacon/item_interaction(mob/living/user, obj/item/tool, list/modifiers)
 	var/turf/our_turf = loc
 	if(our_turf.underfloor_accessibility < UNDERFLOOR_INTERACTABLE)
-		return // prevent intraction when T-scanner revealed
+		return ITEM_INTERACT_BLOCKING// prevent interaction when T-scanner revealed
 
-	if (attacking_item.GetID())
-		if(!panel_open)
-			if (allowed(user))
-				controls_locked = !controls_locked
-				balloon_alert(user, "controls [controls_locked ? "locked" : "unlocked"]")
-				SStgui.update_uis(src)
-			else
-				balloon_alert(user, "access denied")
-		else
-			balloon_alert(user, "panel open!")
-		return
-
-	return ..()
+	if(!tool.GetID())
+		return NONE
+	if(panel_open)
+		balloon_alert(user, "panel open!")
+		return ITEM_INTERACT_BLOCKING
+	if (!allowed(user))
+		balloon_alert(user, "access denied")
+		return ITEM_INTERACT_BLOCKING
+	controls_locked = !controls_locked
+	balloon_alert(user, "controls [controls_locked ? "locked" : "unlocked"]")
+	SStgui.update_uis(src)
+	return ITEM_INTERACT_SUCCESS
 
 /obj/machinery/navbeacon/attack_ai(mob/user)
 	interact(user)

code/game/machinery/requests_console.dm

@@ -517,19 +517,18 @@ GLOBAL_LIST_EMPTY(req_console_ckey_departments)
 		to_chat(user, span_warning("You must open the maintenance panel first!"))
 	return TRUE
 
-/obj/machinery/requests_console/attackby(obj/item/attacking_item, mob/user, list/modifiers, list/attack_modifiers)
-	var/obj/item/card/id/ID = attacking_item.GetID()
-	if(ID)
-		message_verified_by = "[ID.registered_name] ([ID.assignment])"
-		announcement_authenticated = (ACCESS_RC_ANNOUNCE in ID.access)
+/obj/machinery/requests_console/item_interaction(mob/living/user, obj/item/tool, list/modifiers)
+	var/obj/item/card/id/card = tool.GetID()
+	if(card)
+		message_verified_by = "[card.registered_name] ([card.assignment])"
+		announcement_authenticated = (ACCESS_RC_ANNOUNCE in card.access)
 		SStgui.update_uis(src)
-		return
-	if (istype(attacking_item, /obj/item/stamp))
-		var/obj/item/stamp/attacking_stamp = attacking_item
-		message_stamped_by = attacking_stamp.name
+		return ITEM_INTERACT_SUCCESS
+	if (istype(tool, /obj/item/stamp))
+		message_stamped_by = tool.name
 		SStgui.update_uis(src)
-		return
-	return ..()
+		return ITEM_INTERACT_SUCCESS
+	return NONE
 
 /obj/machinery/requests_console/on_deconstruction(disassembled)
 	new /obj/item/wallframe/requests_console(loc)

code/game/machinery/roulette_machine.dm

@@ -116,88 +116,90 @@
 	update_appearance() // Not applicable to all objects.
 
 ///Handles setting ownership and the betting itself.
-/obj/machinery/roulette/attackby(obj/item/W, mob/user, list/modifiers, list/attack_modifiers)
-	if(machine_stat & MAINT && is_wire_tool(W))
+/obj/machinery/roulette/item_interaction(mob/living/user, obj/item/tool, list/modifiers)
+	if(machine_stat & MAINT && is_wire_tool(tool))
 		wires.interact(user)
-		return
+		return ITEM_INTERACT_SUCCESS
 	if(playing)
-		return ..()
-	var/obj/item/card/id/player_card = W.GetID()
-	if(player_card)
-		if(isidcard(W))
-			playsound(src, 'sound/machines/card_slide.ogg', 50, TRUE)
-		else
-			playsound(src, 'sound/machines/terminal/terminal_success.ogg', 50, TRUE)
+		return NONE
+	var/obj/item/card/id/player_card = tool.GetID()
+	if(!player_card)
+		return NONE
+	if(isidcard(tool))
+		playsound(src, 'sound/machines/card_slide.ogg', 50, TRUE)
+	else
+		playsound(src, 'sound/machines/terminal/terminal_success.ogg', 50, TRUE)
 
-		if(machine_stat & MAINT || !on || locked)
-			to_chat(user, span_notice("The machine appears to be disabled."))
-			return FALSE
+	if(machine_stat & MAINT || !on || locked)
+		to_chat(user, span_notice("The machine appears to be disabled."))
+		return ITEM_INTERACT_BLOCKING
 
-		if(!player_card.registered_account)
-			say("You don't have a bank account!")
-			playsound(src, 'sound/machines/buzz/buzz-two.ogg', 30, TRUE)
-			return FALSE
+	if(!player_card.registered_account)
+		say("You don't have a bank account!")
+		playsound(src, 'sound/machines/buzz/buzz-two.ogg', 30, TRUE)
+		return ITEM_INTERACT_BLOCKING
 
-		if(my_card)
-			if(IS_DEPARTMENTAL_CARD(player_card)) // Are they using a department ID
-				say("You cannot gamble with the department budget!")
-				playsound(src, 'sound/machines/buzz/buzz-two.ogg', 30, TRUE)
-				return FALSE
-			if(player_card.registered_account.account_balance < chosen_bet_amount) //Does the player have enough funds
-				say("You do not have the funds to play! Lower your bet or get more money.")
-				playsound(src, 'sound/machines/buzz/buzz-two.ogg', 30, TRUE)
-				return FALSE
-			if(!chosen_bet_amount || isnull(chosen_bet_type))
-				return FALSE
+	if(!my_card)
+		var/msg = tgui_input_text(user, "Name of your roulette wheel", "Roulette Customization", "Roulette Machine", max_length = MAX_NAME_LEN)
+		if(!msg)
+			return ITEM_INTERACT_BLOCKING
+		name = msg
+		desc = "Owned by [player_card.registered_account.account_holder], draws directly from [user.p_their()] account."
+		my_card = player_card
+		RegisterSignal(my_card, COMSIG_QDELETING, PROC_REF(on_my_card_deleted))
+		to_chat(user, span_notice("You link the wheel to your account."))
+		power_change()
+		return ITEM_INTERACT_SUCCESS
 
-			//double to nothing bets
-			var/list/doubles = list(
-				ROULETTE_BET_2TO1_FIRST,
-				ROULETTE_BET_2TO1_SECOND,
-				ROULETTE_BET_2TO1_THIRD,
-				ROULETTE_BET_1TO12,
-				ROULETTE_BET_13TO24,
-				ROULETTE_BET_25TO36
-			)
-			//result of text2num is null if text starts with a character, meaning it's not a singles bet
-			var/single = !isnull(text2num(chosen_bet_type))
-			var/potential_payout_mult
-			if (single)
-				potential_payout_mult = ROULETTE_SINGLES_PAYOUT
-			else
-				if (chosen_bet_type in doubles)
-					potential_payout_mult = ROULETTE_DOZ_COL_PAYOUT
-				else
-					potential_payout_mult = ROULETTE_SIMPLE_PAYOUT
-			var/potential_payout = chosen_bet_amount * potential_payout_mult
+	if(IS_DEPARTMENTAL_CARD(player_card)) // Are they using a department ID
+		say("You cannot gamble with the department budget!")
+		playsound(src, 'sound/machines/buzz/buzz-two.ogg', 30, TRUE)
+		return ITEM_INTERACT_BLOCKING
 
-			if(!check_owner_funds(potential_payout))
-				return FALSE  //owner is too poor
+	if(player_card.registered_account.account_balance < chosen_bet_amount) //Does the player have enough funds
+		say("You do not have the funds to play! Lower your bet or get more money.")
+		playsound(src, 'sound/machines/buzz/buzz-two.ogg', 30, TRUE)
+		return ITEM_INTERACT_BLOCKING
 
-			if(last_anti_spam > world.time) //do not cheat me
-				return FALSE
+	if(!chosen_bet_amount || isnull(chosen_bet_type))
+		return ITEM_INTERACT_BLOCKING
 
-			last_anti_spam = world.time + anti_spam_cooldown
+	//double to nothing bets
+	var/list/doubles = list(
+		ROULETTE_BET_2TO1_FIRST,
+		ROULETTE_BET_2TO1_SECOND,
+		ROULETTE_BET_2TO1_THIRD,
+		ROULETTE_BET_1TO12,
+		ROULETTE_BET_13TO24,
+		ROULETTE_BET_25TO36
+	)
+	//result of text2num is null if text starts with a character, meaning it's not a singles bet
+	var/single = !isnull(text2num(chosen_bet_type))
+	var/potential_payout_mult
+	if(single)
+		potential_payout_mult = ROULETTE_SINGLES_PAYOUT
+	else if(chosen_bet_type in doubles)
+		potential_payout_mult = ROULETTE_DOZ_COL_PAYOUT
+	else
+		potential_payout_mult = ROULETTE_SIMPLE_PAYOUT
+	var/potential_payout = chosen_bet_amount * potential_payout_mult
 
-			icon_state = "rolling" //Prepare the new icon state for rolling before hand.
-			flick("flick_up", src)
-			playsound(src, 'sound/machines/piston/piston_raise.ogg', 70)
-			playsound(src, 'sound/machines/chime.ogg', 50)
+	if(!check_owner_funds(potential_payout))
+		return ITEM_INTERACT_BLOCKING  //owner is too poor
+
+	if(last_anti_spam > world.time) //do not cheat me
+		return ITEM_INTERACT_BLOCKING
+
+	last_anti_spam = world.time + anti_spam_cooldown
+
+	icon_state = "rolling" //Prepare the new icon state for rolling before hand.
+	flick("flick_up", src)
+	playsound(src, 'sound/machines/piston/piston_raise.ogg', 70)
+	playsound(src, 'sound/machines/chime.ogg', 50)
+
+	addtimer(CALLBACK(src, PROC_REF(play), user, player_card, chosen_bet_type, chosen_bet_amount, potential_payout), 4) //Animation first
+	return ITEM_INTERACT_SUCCESS
 
-			addtimer(CALLBACK(src, PROC_REF(play), user, player_card, chosen_bet_type, chosen_bet_amount, potential_payout), 4) //Animation first
-			return TRUE
-		else
-			var/msg = tgui_input_text(user, "Name of your roulette wheel", "Roulette Customization", "Roulette Machine", max_length = MAX_NAME_LEN)
-			if(!msg)
-				return
-			name = msg
-			desc = "Owned by [player_card.registered_account.account_holder], draws directly from [user.p_their()] account."
-			my_card = player_card
-			RegisterSignal(my_card, COMSIG_QDELETING, PROC_REF(on_my_card_deleted))
-			to_chat(user, span_notice("You link the wheel to your account."))
-			power_change()
-			return
-	return ..()
 
 ///deletes the my_card ref to prevent harddels
 /obj/machinery/roulette/proc/on_my_card_deleted(datum/source)

code/game/machinery/shieldgen.dm

@@ -239,33 +239,36 @@
 		set_anchored(FALSE)
 
 
-/obj/machinery/shieldgen/attackby(obj/item/W, mob/user, list/modifiers, list/attack_modifiers)
-	if(istype(W, /obj/item/stack/cable_coil) && (machine_stat & BROKEN) && panel_open)
-		var/obj/item/stack/cable_coil/coil = W
+/obj/machinery/shieldgen/item_interaction(mob/living/user, obj/item/tool, list/modifiers)
+	if(istype(tool, /obj/item/stack/cable_coil) && (machine_stat & BROKEN) && panel_open)
+		var/obj/item/stack/cable_coil/coil = tool
 		if (coil.get_amount() < 1)
 			to_chat(user, span_warning("You need one length of cable to repair [src]!"))
-			return
+			return ITEM_INTERACT_BLOCKING
 		to_chat(user, span_notice("You begin to replace the wires..."))
-		if(do_after(user, 3 SECONDS, target = src))
-			if(coil.get_amount() < 1)
-				return
-			coil.use(1)
-			atom_integrity = max_integrity
-			set_machine_stat(machine_stat & ~BROKEN)
-			to_chat(user, span_notice("You repair \the [src]."))
-			update_appearance()
+		if(!do_after(user, 3 SECONDS, target = src))
+			return ITEM_INTERACT_BLOCKING
+		if(coil.get_amount() < 1)
+			return ITEM_INTERACT_BLOCKING
+		coil.use(1)
+		atom_integrity = max_integrity
+		set_machine_stat(machine_stat & ~BROKEN)
+		to_chat(user, span_notice("You repair \the [src]."))
+		update_appearance()
+		return ITEM_INTERACT_SUCCESS
 
-	else if(W.GetID())
-		if(allowed(user) && !(obj_flags & EMAGGED))
-			locked = !locked
-			to_chat(user, span_notice("You [locked ? "lock" : "unlock"] the controls."))
-		else if(obj_flags & EMAGGED)
+	if(tool.GetID())
+		if(obj_flags & EMAGGED)
 			to_chat(user, span_danger("Error, access controller damaged!"))
-		else
+			return ITEM_INTERACT_BLOCKING
+		if(!allowed(user))
 			to_chat(user, span_danger("Access denied."))
+			return ITEM_INTERACT_BLOCKING
+		locked = !locked
+		to_chat(user, span_notice("You [locked ? "lock" : "unlock"] the controls."))
+		return ITEM_INTERACT_SUCCESS
 
-	else
-		return ..()
+	return NONE
 
 /obj/machinery/shieldgen/emag_act(mob/user, obj/item/card/emag/emag_card)
 	if(obj_flags & EMAGGED)
@@ -464,22 +467,24 @@
 
 	return default_deconstruction_crowbar(user, tool)
 
-/obj/machinery/power/shieldwallgen/attackby(obj/item/W, mob/user, list/modifiers, list/attack_modifiers)
-	. = ..()
-	if(W.GetID())
-		if(allowed(user) && !(obj_flags & EMAGGED))
-			locked = !locked
-			balloon_alert(user, "[locked ? "locked!" : "unlocked"]")
-		else if(obj_flags & EMAGGED)
+/obj/machinery/power/shieldwallgen/item_interaction(mob/living/user, obj/item/tool, list/modifiers)
+	if(tool.GetID())
+		if(obj_flags & EMAGGED)
 			balloon_alert(user, "malfunctioning!")
-		else
+			return ITEM_INTERACT_BLOCKING
+		if(!allowed(user))
 			balloon_alert(user, "no access!")
-		return
+			return ITEM_INTERACT_BLOCKING
+		locked = !locked
+		balloon_alert(user, "[locked ? "locked!" : "unlocked"]")
+		return ITEM_INTERACT_SUCCESS
 
 	add_fingerprint(user)
-	if(is_wire_tool(W) && panel_open)
+	if(is_wire_tool(tool) && panel_open)
 		wires.interact(user)
-		return
+		return ITEM_INTERACT_SUCCESS
+
+	return NONE
 
 
 /obj/machinery/power/shieldwallgen/interact(mob/user)

code/game/machinery/spaceheater.dm

@@ -421,36 +421,40 @@
 			. = TRUE
 
 ///Slightly modified to ignore the open_hatch - it's always open, we hacked it.
-/obj/machinery/space_heater/improvised_chem_heater/attackby(obj/item/item, mob/user, list/modifiers, list/attack_modifiers)
+/obj/machinery/space_heater/improvised_chem_heater/item_interaction(mob/living/user, obj/item/tool, list/modifiers)
 	add_fingerprint(user)
-	if(default_deconstruction_crowbar(user, item))
-		return
-	if(istype(item, /obj/item/stock_parts/power_store/cell))
+	if(istype(tool, /obj/item/stock_parts/power_store/cell))
 		if(cell)
 			to_chat(user, span_warning("There is already a power cell inside!"))
-			return
-		else if(!user.transferItemToLoc(item, src))
-			return
-		cell = item
-		item.add_fingerprint(usr)
+			return ITEM_INTERACT_BLOCKING
+		if(!user.transferItemToLoc(tool, src))
+			return ITEM_INTERACT_BLOCKING
+		cell = tool
+		tool.add_fingerprint(usr)
 
 		user.visible_message(span_notice("\The [user] inserts a power cell into \the [src]."), span_notice("You insert the power cell into \the [src]."))
 		SStgui.update_uis(src)
+		return ITEM_INTERACT_SUCCESS
+
 	//reagent containers
-	if(is_reagent_container(item) && !(item.item_flags & ABSTRACT) && item.is_open_container())
-		. = TRUE //no afterattack
-		var/obj/item/reagent_containers/container = item
+	if(is_reagent_container(tool) && !(tool.item_flags & ABSTRACT) && tool.is_open_container())
+		var/obj/item/reagent_containers/container = tool
 		if(!user.transferItemToLoc(container, src))
-			return
+			return ITEM_INTERACT_BLOCKING
 		replace_beaker(user, container)
 		to_chat(user, span_notice("You add [container] to [src]'s water bath."))
 		ui_interact(user)
-		return
+		return ITEM_INTERACT_SUCCESS
+
+	if(!beaker|| !is_type_in_list(tool, list(/obj/item/reagent_containers/dropper, /obj/item/ph_meter, /obj/item/ph_paper, /obj/item/reagent_containers/syringe)))
+		return NONE
 	//Dropper tools
-	if(beaker)
-		if(is_type_in_list(item, list(/obj/item/reagent_containers/dropper, /obj/item/ph_meter, /obj/item/ph_paper, /obj/item/reagent_containers/syringe)))
-			item.interact_with_atom(beaker, user)
-		return
+	tool.interact_with_atom(beaker, user)
+	return ITEM_INTERACT_SUCCESS
+
+/obj/machinery/space_heater/crowbar_act(mob/living/user, obj/item/tool)
+	add_fingerprint(user)
+	return default_deconstruction_crowbar(user, tool)
 
 /obj/machinery/space_heater/improvised_chem_heater/on_deconstruction(disassembled = TRUE)
 	. = ..()

code/game/machinery/syndicatebomb.dm

@@ -196,24 +196,28 @@
 	return TRUE
 
 
-/obj/machinery/syndicatebomb/attackby(obj/item/I, mob/user, list/modifiers, list/attack_modifiers)
-
-	if(is_wire_tool(I) && open_panel)
+/obj/machinery/syndicatebomb/item_interaction(mob/living/user, obj/item/tool, list/modifiers)
+	if(is_wire_tool(tool) && open_panel)
 		wires.interact(user)
+		return ITEM_INTERACT_SUCCESS
 
-	else if(istype(I, /obj/item/bombcore))
-		if(!payload)
-			if(!user.transferItemToLoc(I, src))
-				return
-			payload = I
-			to_chat(user, span_notice("You place [payload] into [src]."))
-		else
+	if(istype(tool, /obj/item/bombcore))
+		if(payload)
 			to_chat(user, span_warning("[payload] is already loaded into [src]! You'll have to remove it first."))
-	else
-		var/old_integ = atom_integrity
-		. = ..()
-		if((old_integ > atom_integrity) && active && (payload in src))
-			to_chat(user, span_warning("That seems like a really bad idea..."))
+			return ITEM_INTERACT_BLOCKING
+		if(!user.transferItemToLoc(tool, src))
+			return ITEM_INTERACT_BLOCKING
+		payload = tool
+		to_chat(user, span_notice("You place [payload] into [src]."))
+		return ITEM_INTERACT_SUCCESS
+
+	return NONE
+
+/obj/machinery/syndicatebomb/attackby(obj/item/attacking_item, mob/user, list/modifiers, list/attack_modifiers)
+	var/old_integ = atom_integrity
+	. = ..()
+	if((old_integ > atom_integrity) && active && payload)
+		to_chat(user, span_warning("That seems like a really bad idea..."))
 
 /obj/machinery/syndicatebomb/interact(mob/user)
 	wires.interact(user)
@@ -554,23 +558,26 @@
 
 	playsound(loc, 'sound/effects/bamf.ogg', 75, TRUE, 5)
 
-/obj/item/bombcore/chemical/attackby(obj/item/I, mob/user, list/modifiers, list/attack_modifiers)
-	if(I.tool_behaviour == TOOL_CROWBAR && beakers.len > 0)
-		I.play_tool_sound(src)
-		for (var/obj/item/B in beakers)
-			B.forceMove(drop_location())
-			beakers -= B
-		return
-	else if(istype(I, /obj/item/reagent_containers/cup/beaker) || istype(I, /obj/item/reagent_containers/cup/bottle))
-		if(beakers.len < max_beakers)
-			if(!user.transferItemToLoc(I, src))
-				return
-			beakers += I
-			to_chat(user, span_notice("You load [src] with [I]."))
-		else
-			to_chat(user, span_warning("[I] won't fit! \The [src] can only hold up to [max_beakers] containers."))
-			return
-	..()
+/obj/item/bombcore/chemical/item_interaction(mob/living/user, obj/item/tool, list/modifiers)
+	if(!istype(tool, /obj/item/reagent_containers/cup/beaker) && !istype(tool, /obj/item/reagent_containers/cup/bottle))
+		return NONE
+	if(beakers.len >= max_beakers)
+		to_chat(user, span_warning("[tool] won't fit! \The [src] can only hold up to [max_beakers] containers."))
+		return ITEM_INTERACT_BLOCKING
+	if(!user.transferItemToLoc(tool, src))
+		return ITEM_INTERACT_BLOCKING
+	beakers += tool
+	to_chat(user, span_notice("You load [src] with [tool]."))
+	return ITEM_INTERACT_SUCCESS
+
+/obj/item/bombcore/chemical/crowbar_act(mob/living/user, obj/item/tool)
+	if(!beakers.len)
+		return NONE
+	tool.play_tool_sound(src)
+	for (var/obj/item/beaker in beakers)
+		beaker.forceMove(drop_location())
+		beakers -= beaker
+	return ITEM_INTERACT_SUCCESS
 
 /obj/item/bombcore/chemical/on_craft_completion(list/components, datum/crafting_recipe/current_recipe, atom/crafter)
 	// Using different grenade casings, causes the payload to have different properties.

code/game/objects/items/tools/janitorial/janitor_key.dm

@@ -47,7 +47,7 @@
  */
 /obj/item/access_key/proc/attempt_open_door(mob/living/user, obj/machinery/door/airlock)
 	if(DOING_INTERACTION_WITH_TARGET(user, airlock))
-		return
+		return FALSE
 	user.balloon_alert_to_viewers("fumbles with keys...", "finding key...")
 	user.playsound_local(src, 'sound/items/rattling_keys.ogg', 25, TRUE)
 	if(!do_after(user, 3 SECONDS, airlock))