Moves a great many things from attackby() to item_interaction() (#96642)

## About The Pull Request

21 things.
Additionally, an actual refactor(a real one) of refunding of item-based
spellbook entries, as in the three summons, which hasn't worked for four
years and now does.
Lastly, the holopayment stand IDs can project can now accept payment.


## Why It's Good For The Game

They want you to think this is worth 210 gbp, don't believe the lies

## Changelog
🆑

fix: Wizards can now successfully refund summoning items
fix: Holopayment stands can now take payment

code: 21 things have been moved from attackby() to item_interaction()

/🆑

code/game/machinery/civilian_bounty/bounty_machinery.dm

@@ -41,12 +41,13 @@
 	///Cooldown for printing the bounty sheet, and not breaking people's eardrums.
 	COOLDOWN_DECLARE(sheet_printer_cooldown)
 
-/obj/machinery/computer/piratepad_control/civilian/attackby(obj/item/I, mob/living/user, list/modifiers, list/attack_modifiers)
-	if(isidcard(I))
-		if(id_insert(user, I, inserted_scan_id))
-			inserted_scan_id = I
-			return TRUE
-	return ..()
+/obj/machinery/computer/piratepad_control/civilian/item_interaction(mob/living/user, obj/item/tool, list/modifiers)
+	if(!isidcard(tool))
+		return NONE
+	if(!id_insert(user, tool, inserted_scan_id))
+		return ITEM_INTERACT_BLOCKING
+	inserted_scan_id = tool
+	return ITEM_INTERACT_SUCCESS
 
 /obj/machinery/computer/piratepad_control/multitool_act(mob/living/user, obj/item/multitool/I)
 	if(istype(I) && istype(I.buffer,/obj/machinery/piratepad/civilian))

code/game/machinery/prisonlabor.dm

@@ -26,20 +26,21 @@
 	QDEL_NULL(current_plate)
 	. = ..()
 
-/obj/machinery/plate_press/attackby(obj/item/I, mob/living/user, list/modifiers, list/attack_modifiers)
+/obj/machinery/plate_press/item_interaction(mob/living/user, obj/item/tool, list/modifiers)
+	if(!istype(tool, /obj/item/stack/license_plates/empty))
+		return NONE
 	if(!is_operational)
-		to_chat(user, span_warning("[src] has to be on to do this!"))
-		return FALSE
+		to_chat(user, span_warning("[src] has to be on to be loaded!"))
+		return ITEM_INTERACT_BLOCKING
 	if(current_plate)
 		to_chat(user, span_warning("[src] already has a plate in it!"))
-		return FALSE
-	if(istype(I, /obj/item/stack/license_plates/empty))
-		var/obj/item/stack/license_plates/empty/plate = I
-		plate.use(1)
-		current_plate = new plate.type(src, 1) //Spawn a new single sheet in the machine
-		update_appearance()
-	else
-		return ..()
+		return ITEM_INTERACT_BLOCKING
+
+	var/obj/item/stack/license_plates/empty/plate = tool
+	plate.use(1)
+	current_plate = new plate.type(src, 1) //Spawn a new single sheet in the machine
+	update_appearance()
+	return ITEM_INTERACT_SUCCESS
 
 /obj/machinery/plate_press/attack_hand(mob/living/user, list/modifiers)
 	. = ..()

code/game/objects/effects/posters/poster.dm

@@ -56,18 +56,19 @@
 	. = ..()
 	. += span_notice("You can booby-trap the poster by using a glass shard on it before you put it up.")
 
-/obj/item/poster/attackby(obj/item/I, mob/user, list/modifiers, list/attack_modifiers)
-	if(!istype(I, /obj/item/shard))
-		return ..()
+/obj/item/poster/item_interaction(mob/living/user, obj/item/tool, list/modifiers)
+	if(!istype(tool, /obj/item/shard))
+		return NONE
 
-	if (locate(/obj/item/shard) in (poster_structure?.contents || contents))
+	if(locate(/obj/item/shard) in (poster_structure?.contents || contents))
 		balloon_alert(user, "already trapped!")
-		return
+		return ITEM_INTERACT_BLOCKING
 
-	if(!user.transferItemToLoc(I, src))
-		return
+	if(!user.transferItemToLoc(tool, src))
+		return ITEM_INTERACT_BLOCKING
 
-	to_chat(user, span_notice("You conceal \the [I] inside the rolled up poster."))
+	to_chat(user, span_notice("You conceal \the [tool] inside the rolled up poster."))
+	return ITEM_INTERACT_SUCCESS
 
 /obj/item/poster/interact_with_atom(turf/closed/wall_structure, mob/living/user, list/modifiers)
 	if(!isclosedturf(wall_structure))

code/game/objects/items/cardboard_cutouts.dm

@@ -80,12 +80,11 @@
 	pushed_over = FALSE
 	tacticool = AddComponent(/datum/component/tactical)
 
-/obj/item/cardboard_cutout/attackby(obj/item/I, mob/living/user, list/modifiers, list/attack_modifiers)
-	if(istype(I, /obj/item/toy/crayon))
-		change_appearance(I, user)
-		return TRUE
-
-	return ..()
+/obj/item/cardboard_cutout/item_interaction(mob/living/user, obj/item/tool, list/modifiers)
+	if(!istype(tool, /obj/item/toy/crayon))
+		return NONE
+	change_appearance(tool, user)
+	return ITEM_INTERACT_SUCCESS
 
 /obj/item/cardboard_cutout/take_damage(damage_amount, damage_type, damage_flag, sound_effect, attack_dir, armour_penetration)
 	. = ..()

code/game/objects/items/puzzle_pieces.dm

@@ -124,13 +124,13 @@
 	desc = "This door only opens when a keycard is swiped. It looks virtually indestructible."
 	uses_queuelinks = FALSE
 
-/obj/machinery/door/puzzle/keycard/attackby(obj/item/attacking_item, mob/user, list/modifiers, list/attack_modifiers)
-	. = ..()
-	if(!istype(attacking_item, /obj/item/keycard))
-		return
-	var/obj/item/keycard/key = attacking_item
-	if(!try_puzzle_open(key.puzzle_id))
+/obj/machinery/door/puzzle/keycard/item_interaction(mob/living/user, obj/item/tool, list/modifiers)
+	if(!istype(tool, /obj/item/keycard))
+		return NONE
+	if(!try_puzzle_open(astype(tool, /obj/item/keycard).puzzle_id))
 		to_chat(user, span_notice("[src] buzzes. This must not be the right key."))
+		return ITEM_INTERACT_BLOCKING
+	return ITEM_INTERACT_SUCCESS
 
 //Test doors. Gives admins a few doors to use quickly should they so choose for events.
 /obj/machinery/door/puzzle/keycard/yellow_required

code/game/objects/items/secret_documents.dm

@@ -66,14 +66,17 @@
 			var/obj/item/documents/photocopy/C = copy
 			copy_type = C.copy_type
 
-/obj/item/documents/photocopy/attackby(obj/item/O, mob/user, list/modifiers, list/attack_modifiers)
-	if(istype(O, /obj/item/toy/crayon/red) || istype(O, /obj/item/toy/crayon/blue))
-		if (forgedseal)
-			to_chat(user, span_warning("You have already forged a seal on [src]!"))
-		else
-			var/obj/item/toy/crayon/C = O
-			name = "[C.crayon_color] secret documents"
-			icon_state = "docs_[C.crayon_color]"
-			forgedseal = C.crayon_color
-			to_chat(user, span_notice("You forge the official seal with a [C.crayon_color] crayon. No one will notice... right?"))
-			update_appearance()
+/obj/item/documents/photocopy/item_interaction(mob/living/user, obj/item/tool, list/modifiers)
+	if(!istype(tool, /obj/item/toy/crayon/red) && !istype(tool, /obj/item/toy/crayon/blue))
+		return NONE
+	if (forgedseal)
+		to_chat(user, span_warning("You have already forged a seal on [src]!"))
+		return ITEM_INTERACT_BLOCKING
+
+	var/obj/item/toy/crayon/C = tool
+	name = "[C.crayon_color] secret documents"
+	icon_state = "docs_[C.crayon_color]"
+	forgedseal = C.crayon_color
+	to_chat(user, span_notice("You forge the official seal with a [C.crayon_color] crayon. No one will notice... right?"))
+	update_appearance()
+	return ITEM_INTERACT_SUCCESS

code/modules/antagonists/wizard/equipment/spellbook_entries/_entry.dm

@@ -228,6 +228,16 @@
 	var/was_put_in_hands = user.put_in_hands(to_equip)
 	to_chat(user, span_notice("\A [to_equip.name] has been summoned [was_put_in_hands ? "in your hands" : "at your feet"]."))
 
+/datum/spellbook_entry/item/can_refund(mob/living/carbon/human/user, obj/item/spellbook/book, obj/item/refunding_item)
+	if(HAS_TRAIT(user, TRAIT_SPELLS_LOTTERY))
+		to_chat(user, span_notice("No refund."))
+		return FALSE
+	if(!book.refunds_allowed) // We're not doing a check for refundable here because they're not refundable in-book.
+		return FALSE
+	if(refunding_item.type != item_path)
+		return FALSE
+	return TRUE
+
 /// Ritual, these cause station wide effects and are (pretty much) a blank slate to implement stuff in
 /datum/spellbook_entry/summon
 	category = "Rituals"

code/modules/antagonists/wizard/equipment/spellbook_entries/assistance.dm

@@ -64,7 +64,6 @@
 	desc = "A magical contract binding an apprentice wizard to your service, using it will summon them to your side."
 	item_path = /obj/item/antag_spawner/contract
 	category = SPELLBOOK_CATEGORY_ASSISTANCE
-	refundable = TRUE
 
 /datum/spellbook_entry/item/guardian
 	name = "Guardian Deck"
@@ -82,7 +81,6 @@
 	item_path = /obj/item/antag_spawner/slaughter_demon
 	limit = 3
 	category = SPELLBOOK_CATEGORY_ASSISTANCE
-	refundable = TRUE
 
 /datum/spellbook_entry/item/hugbottle
 	name = "Bottle of Tickles"
@@ -97,7 +95,6 @@
 	cost = 1 //non-destructive; it's just a jape, sibling!
 	limit = 3
 	category = SPELLBOOK_CATEGORY_ASSISTANCE
-	refundable = TRUE
 
 /datum/spellbook_entry/item/vendormancer
 	name = "Scepter of Vendormancy"

code/modules/antagonists/wizard/equipment/wizard_spellbook.dm

@@ -74,55 +74,39 @@
 
 	return ..()
 
-/obj/item/spellbook/attackby(obj/item/O, mob/user, list/modifiers, list/attack_modifiers)
+/obj/item/spellbook/item_interaction(mob/living/user, obj/item/tool, list/modifiers)
 	// This can be generalized in the future, but for now it stays
-	if(istype(O, /obj/item/antag_spawner/contract))
-		var/datum/spellbook_entry/item/contract/contract_entry = locate() in entries
-		if(!istype(contract_entry))
-			to_chat(user, span_warning("[src] doesn't seem to want to refund [O]."))
-			return
-		if(!contract_entry.can_refund(user, src))
-			to_chat(user, span_warning("You can't refund [src]."))
-			return
-		var/obj/item/antag_spawner/contract/contract = O
-		if(contract.used)
+	var/datum/spellbook_entry/item/spawner_entry
+	var/success_string
+	if(istype(tool, /obj/item/antag_spawner/contract))
+		if(astype(tool, /obj/item/antag_spawner/contract).used)
 			to_chat(user, span_warning("The contract has been used, you can't get your points back now!"))
-			return
+			return ITEM_INTERACT_BLOCKING
+		spawner_entry = locate(/datum/spellbook_entry/item/contract) in entries
+		success_string = "You feed the contract back into the spellbook, refunding your points."
 
-		to_chat(user, span_notice("You feed the contract back into the spellbook, refunding your points."))
-		uses += contract_entry.cost
-		contract_entry.times--
-		qdel(O)
+	if(istype(tool, /obj/item/antag_spawner/slaughter_demon/laughter))
+		spawner_entry = locate(/datum/spellbook_entry/item/hugbottle) in entries
+		success_string = "On second thought, maybe summoning a demon isn't a funny idea. You refund your points."
 
-	else if(istype(O, /obj/item/antag_spawner/slaughter_demon/laughter))
-		var/datum/spellbook_entry/item/hugbottle/demon_entry = locate() in entries
-		if(!istype(demon_entry))
-			to_chat(user, span_warning("[src] doesn't seem to want to refund [O]."))
-			return
-		if(!demon_entry.can_refund(user, src))
-			to_chat(user, span_warning("You can't refund [O]."))
-			return
+	else if(istype(tool, /obj/item/antag_spawner/slaughter_demon))
+		spawner_entry = locate(/datum/spellbook_entry/item/bloodbottle) in entries
+		success_string = "On second thought, maybe summoning a demon is a bad idea. You refund your points."
 
-		to_chat(user, span_notice("On second thought, maybe summoning a demon isn't a funny idea. You refund your points."))
-		uses += demon_entry.cost
-		demon_entry.times--
-		qdel(O)
+	if(isnull(success_string))
+		return NONE
+	if(!istype(spawner_entry)) // No success_string means it isn't a valid item, no spawner entry means the book doesn't have it(somehow)(they had this check before I got here)
+		to_chat(user, span_warning("[src] doesn't seem to want to refund [tool]."))
+		return ITEM_INTERACT_BLOCKING
+	if(!spawner_entry.can_refund(user, src, tool))
+		to_chat(user, span_warning("You can't refund [src]."))
+		return ITEM_INTERACT_BLOCKING
 
-	else if(istype(O, /obj/item/antag_spawner/slaughter_demon))
-		var/datum/spellbook_entry/item/bloodbottle/demon_entry = locate() in entries
-		if(!istype(demon_entry))
-			to_chat(user, span_warning("[src] doesn't seem to want to refund [O]."))
-			return
-		if(!demon_entry.can_refund(user, src))
-			to_chat(user, span_warning("You can't refund [O]."))
-			return
-
-		to_chat(user, span_notice("On second thought, maybe summoning a demon is a bad idea. You refund your points."))
-		uses += demon_entry.cost
-		demon_entry.times--
-		qdel(O)
-
-	return ..()
+	to_chat(user, span_notice(success_string))
+	uses += spawner_entry.cost
+	spawner_entry.times--
+	qdel(tool)
+	return ITEM_INTERACT_SUCCESS
 
 /// Instantiates our list of spellbook entries.
 /obj/item/spellbook/proc/prepare_spells()

code/modules/economy/holopay.dm

@@ -74,60 +74,57 @@
 	linked_card = null
 	return ..()
 
-/obj/structure/holopay/attackby(obj/item/held_item, mob/item_holder, list/modifiers, list/attack_modifiers)
-	var/mob/living/user = item_holder
-	if(!isliving(user))
-		return ..()
+/obj/structure/holopay/item_interaction(mob/living/user, obj/item/tool, list/modifiers)
 	/// Users can pay with an ID to skip the UI
-	if(isidcard(held_item))
-		if(istype(held_item, /obj/item/card/id/departmental_budget))
+	if(isidcard(tool))
+		if(istype(tool, /obj/item/card/id/departmental_budget))
 			balloon_alert(user, "invalid payment card")
 			to_chat(user, span_warning("You cannot use a departamental card for this."))
-			return FALSE
-		if(force_fee && tgui_alert(item_holder, "This holopay has a [force_fee] [MONEY_SYMBOL] fee. Confirm?", "Holopay Fee", list("Pay", "Cancel")) != "Pay")
-			return TRUE
+			return ITEM_INTERACT_BLOCKING
+		if(force_fee && tgui_alert(user, "This holopay has a [force_fee] [MONEY_SYMBOL] fee. Confirm?", "Holopay Fee", list("Pay", "Cancel")) != "Pay")
+			return ITEM_INTERACT_BLOCKING
 		process_payment(user)
-		return TRUE
+		return ITEM_INTERACT_SUCCESS
 	/// Users can also pay by holochip
-	if(istype(held_item, /obj/item/holochip))
+	if(istype(tool, /obj/item/holochip))
 		/// Account checks
-		var/obj/item/holochip/chip = held_item
+		var/obj/item/holochip/chip = tool
 		if(!chip.credits)
 			balloon_alert(user, "holochip is empty")
 			to_chat(user, span_warning("There doesn't seem to be any [MONEY_NAME] here."))
-			return FALSE
+			return ITEM_INTERACT_BLOCKING
 		/// Charges force fee or uses pay what you want
 		var/cash_deposit = force_fee || tgui_input_number(user, "How much? (Max: [chip.credits])", "Patronage", max_value = chip.credits)
 		/// Exit sanity checks
 		if(!cash_deposit)
-			return TRUE
-		if(QDELETED(held_item) || QDELETED(user) || QDELETED(src) || !user.can_perform_action(src, FORBID_TELEKINESIS_REACH))
-			return FALSE
+			return ITEM_INTERACT_BLOCKING
+		if(QDELETED(tool) || QDELETED(user) || QDELETED(src) || !user.can_perform_action(src, FORBID_TELEKINESIS_REACH))
+			return ITEM_INTERACT_BLOCKING
 		if(!chip.spend(cash_deposit, FALSE))
 			balloon_alert(user, "insufficient [MONEY_NAME]")
 			to_chat(user, span_warning("You don't have enough [MONEY_NAME] to pay with this chip."))
-			return FALSE
+			return ITEM_INTERACT_BLOCKING
 		/// Success: Alert buyer
 		alert_buyer(user, cash_deposit)
-		return TRUE
+		return ITEM_INTERACT_SUCCESS
 	/// Throws errors if they try to use space cash
-	if(istype(held_item, /obj/item/stack/spacecash))
+	if(istype(tool, /obj/item/stack/spacecash))
 		to_chat(user, "What is this, the 2000s? We only take card here.")
-		return TRUE
-	if(istype(held_item, /obj/item/coin))
+		return ITEM_INTERACT_BLOCKING
+	if(istype(tool, /obj/item/coin))
 		to_chat(user, "What is this, the 1800s? We only take card here.")
-		return TRUE
-	return ..()
+		return ITEM_INTERACT_BLOCKING
+	return NONE
 
-/obj/structure/holopay/attackby_secondary(obj/item/weapon, mob/user, list/modifiers, list/attack_modifiers)
+/obj/structure/holopay/item_interaction_secondary(mob/living/user, obj/item/tool, list/modifiers)
 	/// Can kill it by right-clicking with ID because it seems useful and intuitive, to me, at least
-	if(!isidcard(weapon))
-		return ..()
-	var/obj/item/card/id/attacking_id = weapon
+	if(!isidcard(tool))
+		return NONE
+	var/obj/item/card/id/attacking_id = tool
 	if(!attacking_id.my_store || attacking_id.my_store != src)
-		return ..()
+		return ITEM_INTERACT_BLOCKING
 	dissipate()
-	return SECONDARY_ATTACK_CANCEL_ATTACK_CHAIN
+	return ITEM_INTERACT_SUCCESS
 
 /obj/structure/holopay/ui_interact(mob/user, datum/tgui/ui)
 	. = ..()
@@ -259,7 +256,7 @@
 	/// Account checks
 	var/obj/item/card/id/id_card
 	id_card = user.get_idcard(TRUE)
-	if(isnull(id_card) || id_card.can_be_used_in_payment(user))
+	if(isnull(id_card) || !id_card.can_be_used_in_payment(user))
 		balloon_alert(user, "invalid account")
 		to_chat(user, span_warning("You don't have a valid account."))
 		return FALSE

code/modules/library/skill_learning/skill_station.dm

@@ -83,16 +83,16 @@
 	else
 		toggle_open()
 
-/obj/machinery/skill_station/attackby(obj/item/I, mob/living/user, list/modifiers, list/attack_modifiers)
-	if(istype(I,/obj/item/skillchip))
-		if(inserted_skillchip)
-			to_chat(user,span_notice("There's already a skillchip inside."))
-			return
-		if(!user.transferItemToLoc(I, src))
-			return
-		inserted_skillchip = I
-		return
-	return ..()
+/obj/machinery/skill_station/item_interaction(mob/living/user, obj/item/tool, list/modifiers)
+	if(!istype(tool,/obj/item/skillchip))
+		return NONE
+	if(inserted_skillchip)
+		to_chat(user,span_notice("There's already a skillchip inside."))
+		return ITEM_INTERACT_BLOCKING
+	if(!user.transferItemToLoc(tool, src))
+		return ITEM_INTERACT_BLOCKING
+	inserted_skillchip = tool
+	return ITEM_INTERACT_SUCCESS
 
 /obj/machinery/skill_station/dump_contents()
 	. = ..()

code/modules/mining/equipment/kinetic_crusher/kinetic_crusher.dm

@@ -119,12 +119,11 @@
 	for(var/obj/item/crusher_trophy/crusher_trophy as anything in trophies)
 		. += span_notice("It has \a [crusher_trophy] attached, which causes [crusher_trophy.effect_desc()].")
 
-/obj/item/kinetic_crusher/attackby(obj/item/attacking_item, mob/user, list/modifiers, list/attack_modifiers)
-	if(istype(attacking_item, /obj/item/crusher_trophy))
-		var/obj/item/crusher_trophy/crusher_trophy = attacking_item
-		crusher_trophy.add_to(src, user)
-		return
-	return ..()
+/obj/item/kinetic_crusher/item_interaction(mob/living/user, obj/item/tool, list/modifiers)
+	if(istype(tool, /obj/item/crusher_trophy))
+		astype(tool, /obj/item/crusher_trophy).add_to(src, user)
+		return ITEM_INTERACT_SUCCESS
+	return NONE
 
 /obj/item/kinetic_crusher/crowbar_act(mob/living/user, obj/item/tool)
 	. = ..()

code/modules/mob/living/basic/vermin/mouse.dm

@@ -381,24 +381,22 @@
 	qdel(src)
 	return LAZARUS_INJECTOR_USED
 
-/obj/item/food/deadmouse/attackby(obj/item/attacking_item, mob/user, list/modifiers, list/attack_modifiers)
-	var/mob/living/living_user = user
-	if(istype(living_user) && attacking_item.get_sharpness() && living_user.combat_mode)
-		if(!isturf(loc))
-			balloon_alert(user, "can't butcher here!")
-			return
+/obj/item/food/deadmouse/item_interaction(mob/living/user, obj/item/tool, list/modifiers)
+	if(!tool.get_sharpness() || !user.combat_mode)
+		return NONE
+	if(!isturf(loc))
+		balloon_alert(user, "can't butcher here!")
+		return ITEM_INTERACT_BLOCKING
 
-		balloon_alert(user, "butchering...")
-		if(!do_after(user, 0.75 SECONDS, src))
-			balloon_alert(user, "interrupted!")
-			return
+	balloon_alert(user, "butchering...")
+	if(!do_after(user, 0.75 SECONDS, src))
+		balloon_alert(user, "interrupted!")
+		return ITEM_INTERACT_BLOCKING
 
-		loc.balloon_alert(user, "butchered")
-		new /obj/item/food/meat/slab/mouse(loc)
-		qdel(src)
-		return
-
-	return ..()
+	loc.balloon_alert(user, "butchered")
+	new /obj/item/food/meat/slab/mouse(loc)
+	qdel(src)
+	return ITEM_INTERACT_SUCCESS
 
 /obj/item/food/deadmouse/interact_with_atom(atom/interacting_with, mob/living/user, list/modifiers)
 	if(isnull(reagents) || !interacting_with.is_open_container())

code/modules/paperwork/clipboard.dm

@@ -121,25 +121,35 @@
 		return TRUE
 	. = ..()
 
-/obj/item/clipboard/attackby(obj/item/weapon, mob/user, list/modifiers, list/attack_modifiers)
-	if(istype(weapon, /obj/item/paper))
+/obj/item/clipboard/item_interaction(mob/living/user, obj/item/tool, list/modifiers)
+	if(istype(tool, /obj/item/paper))
 		//Add paper into the clipboard
-		if(!user.transferItemToLoc(weapon, src))
-			return
+		if(!user.transferItemToLoc(tool, src))
+			return ITEM_INTERACT_BLOCKING
 		if(top_paper)
 			UnregisterSignal(top_paper, COMSIG_ATOM_UPDATED_ICON)
-		RegisterSignal(weapon, COMSIG_ATOM_UPDATED_ICON, PROC_REF(on_top_paper_change))
-		top_paper = weapon
-		to_chat(user, span_notice("You clip [weapon] onto [src]."))
-	else if(istype(weapon, /obj/item/pen) && !pen)
+		RegisterSignal(tool, COMSIG_ATOM_UPDATED_ICON, PROC_REF(on_top_paper_change))
+		top_paper = tool
+		to_chat(user, span_notice("You clip [tool] onto [src]."))
+		update_appearance()
+		return ITEM_INTERACT_SUCCESS
+
+	if(istype(tool, /obj/item/pen) && !pen)
 		//Add a pen into the clipboard, attack (write) if there is already one
-		if(!usr.transferItemToLoc(weapon, src))
-			return
-		pen = weapon
-		to_chat(usr, span_notice("You slot [weapon] into [src]."))
-	else if(top_paper)
-		top_paper.attackby(user.get_active_held_item(), user)
-	update_appearance()
+		if(!user.transferItemToLoc(tool, src))
+			return ITEM_INTERACT_BLOCKING
+		pen = tool
+		to_chat(user, span_notice("You slot [tool] into [src]."))
+		update_appearance()
+		return ITEM_INTERACT_SUCCESS
+
+	if(top_paper)
+		top_paper.item_interaction(user, user.get_active_held_item())
+		update_appearance()
+		return ITEM_INTERACT_SUCCESS
+
+	return NONE
+
 
 /obj/item/clipboard/attack_self(mob/user)
 	add_fingerprint(usr)

code/modules/paperwork/filingcabinet.dm

@@ -43,23 +43,27 @@
 	for(var/obj/item/obj in src)
 		obj.forceMove(loc)
 
-/obj/structure/filingcabinet/attackby(obj/item/P, mob/living/user, list/modifiers, list/attack_modifiers)
-	if(P.tool_behaviour == TOOL_WRENCH && LAZYACCESS(modifiers, RIGHT_CLICK))
-		to_chat(user, span_notice("You begin to [anchored ? "unwrench" : "wrench"] [src]."))
-		if(P.use_tool(src, user, 20, volume=50))
-			to_chat(user, span_notice("You successfully [anchored ? "unwrench" : "wrench"] [src]."))
-			set_anchored(!anchored)
-	else if(P.w_class < WEIGHT_CLASS_NORMAL)
-		if(!user.transferItemToLoc(P, src))
-			return
-		to_chat(user, span_notice("You put [P] in [src]."))
+/obj/structure/filingcabinet/item_interaction(mob/living/user, obj/item/tool, list/modifiers)
+	if(tool.w_class < WEIGHT_CLASS_NORMAL)
+		if(!user.transferItemToLoc(tool, src))
+			return ITEM_INTERACT_BLOCKING
+		to_chat(user, span_notice("You put [tool] in [src]."))
 		icon_state = "[initial(icon_state)]-open"
 		sleep(0.5 SECONDS)
 		icon_state = initial(icon_state)
-	else if(!user.combat_mode || (P.item_flags & NOBLUDGEON))
-		to_chat(user, span_warning("You can't put [P] in [src]!"))
-	else
-		return ..()
+		return ITEM_INTERACT_SUCCESS
+	if(!user.combat_mode || (tool.item_flags & NOBLUDGEON))
+		to_chat(user, span_warning("You can't put [tool] in [src]!"))
+		return ITEM_INTERACT_BLOCKING
+	return NONE
+
+/obj/structure/filingcabinet/wrench_act_secondary(mob/living/user, obj/item/tool)
+	to_chat(user, span_notice("You begin to [anchored ? "unwrench" : "wrench"] [src]."))
+	if(!tool.use_tool(src, user, 20, volume=50))
+		return ITEM_INTERACT_BLOCKING
+	to_chat(user, span_notice("You successfully [anchored ? "unwrench" : "wrench"] [src]."))
+	set_anchored(!anchored)
+	return ITEM_INTERACT_SUCCESS
 
 /obj/structure/filingcabinet/attack_hand(mob/living/carbon/user, list/modifiers)
 	. = ..()

code/modules/paperwork/paper.dm

@@ -415,44 +415,44 @@ GAME_VERB_SRC(/obj/item/paper, rename, usr, "Rename paper", null)
 		user.put_in_hands(new_plane)
 	return new_plane
 
-/obj/item/paper/attackby(obj/item/attacking_item, mob/living/user, list/modifiers, list/attack_modifiers)
+/obj/item/paper/item_interaction(mob/living/user, obj/item/tool, list/modifiers)
 	// Enable picking paper up by clicking on it with the clipboard or paper bin
-	if(istype(attacking_item, /obj/item/clipboard) || istype(attacking_item, /obj/item/paper_bin))
-		attacking_item.attackby(src, user)
-		return
+	if(istype(tool, /obj/item/clipboard) || istype(tool, /obj/item/paper_bin))
+		tool.item_interaction(user, src)
+		return ITEM_INTERACT_SUCCESS
 
 	// Handle writing items.
-	var/writing_stats = attacking_item.get_writing_implement_details()
+	var/writing_stats = tool.get_writing_implement_details()
 
 	if(!writing_stats)
 		ui_interact(user)
-		return ..()
+		return NONE
 
 	if(writing_stats["interaction_mode"] == MODE_WRITING)
-		if(!user.can_write(attacking_item))
-			return
+		if(!user.can_write(tool))
+			return ITEM_INTERACT_BLOCKING
 		if(get_total_length() >= MAX_PAPER_LENGTH)
 			to_chat(user, span_warning("This sheet of paper is full!"))
-			return
+			return ITEM_INTERACT_BLOCKING
 
 		ui_interact(user)
-		return
+		return ITEM_INTERACT_SUCCESS
 
 	// Handle stamping items.
 	if(writing_stats["interaction_mode"] == MODE_STAMPING)
 		if(!user.can_read(src) || user.is_blind())
 			//The paper's stampable window area is assumed approx 300x400
 			add_stamp(writing_stats["stamp_class"], rand(0, 300), rand(0, 400), rand(0, 360), writing_stats["stamp_icon_state"], stamp_icon = writing_stats["stamp_icon"])
-			user.visible_message(span_notice("[user] blindly stamps [src] with \the [attacking_item]!"))
-			to_chat(user, span_notice("You stamp [src] with \the [attacking_item] the best you can!"))
+			user.visible_message(span_notice("[user] blindly stamps [src] with \the [tool]!"))
+			to_chat(user, span_notice("You stamp [src] with \the [tool] the best you can!"))
 			playsound(src, 'sound/items/handling/standard_stamp.ogg', 50, vary = TRUE)
 		else
 			to_chat(user, span_notice("You ready your stamp over the paper! "))
 			ui_interact(user)
-		return
+		return ITEM_INTERACT_SUCCESS
 
 	ui_interact(user)
-	return ..()
+	return NONE
 
 /// Secondary right click interaction to quickly stamp things
 /obj/item/paper/item_interaction_secondary(mob/living/user, obj/item/tool, list/modifiers)

code/modules/paperwork/paperbin.dm

@@ -118,27 +118,29 @@
 	add_fingerprint(user)
 	return ..()
 
-/obj/item/paper_bin/attackby(obj/item/I, mob/user, list/modifiers, list/attack_modifiers)
+/obj/item/paper_bin/item_interaction(mob/living/user, obj/item/tool, list/modifiers)
 	if(at_overlay_limit())
 		dump_contents(drop_location(), TRUE)
-		return
-	if(istype(I, /obj/item/paper))
-		var/obj/item/paper/paper = I
-		if(!user.transferItemToLoc(paper, src, silent = FALSE))
-			return
-		to_chat(user, span_notice("You put [paper] in [src]."))
-		paper_stack += paper
+		return ITEM_INTERACT_SUCCESS
+
+	if(istype(tool, /obj/item/paper))
+		if(!user.transferItemToLoc(tool, src, silent = FALSE))
+			return ITEM_INTERACT_BLOCKING
+		to_chat(user, span_notice("You put [tool] in [src]."))
+		paper_stack += tool
 		total_paper += 1
 		update_appearance()
-	else if(istype(I, /obj/item/pen) && !bin_pen)
-		var/obj/item/pen/pen = I
-		if(!user.transferItemToLoc(pen, src, silent = FALSE))
-			return
-		to_chat(user, span_notice("You put [pen] in [src]."))
-		bin_pen = pen
+		return ITEM_INTERACT_SUCCESS
+
+	if(istype(tool, /obj/item/pen) && !bin_pen)
+		if(!user.transferItemToLoc(tool, src, silent = FALSE))
+			return ITEM_INTERACT_BLOCKING
+		to_chat(user, span_notice("You put [tool] in [src]."))
+		bin_pen = tool
 		update_appearance()
-	else
-		return ..()
+		return ITEM_INTERACT_SUCCESS
+
+	return NONE
 
 /obj/item/paper_bin/proc/at_overlay_limit()
 	return overlays.len >= MAX_ATOM_OVERLAYS - 1
@@ -253,16 +255,19 @@
 /obj/item/paper_bin/bundlenatural/fire_act(exposed_temperature, exposed_volume)
 	qdel(src)
 
-/obj/item/paper_bin/bundlenatural/attackby(obj/item/W, mob/user)
-	if(istype(W, /obj/item/paper/carbon))
-		to_chat(user, span_warning("[W] won't fit into [src]."))
-		return
-	if(W.get_sharpness())
-		if(W.use_tool(src, user, 1 SECONDS))
-			to_chat(user, span_notice("You slice the cable from [src]."))
-			deconstruct(TRUE)
-	else
-		..()
+/obj/item/paper_bin/bundlenatural/item_interaction(mob/living/user, obj/item/tool, list/modifiers)
+	if(istype(tool, /obj/item/paper/carbon))
+		to_chat(user, span_warning("[tool] won't fit into [src]."))
+		return ITEM_INTERACT_BLOCKING
+
+	if(tool.get_sharpness())
+		if(!tool.use_tool(src, user, 1 SECONDS))
+			return ITEM_INTERACT_BLOCKING
+		to_chat(user, span_notice("You slice the cable from [src]."))
+		deconstruct(TRUE)
+		return ITEM_INTERACT_SUCCESS
+
+	return ..()
 
 /obj/item/paper_bin/carbon
 	name = "carbon paper bin"

code/modules/paperwork/paperplane.dm

@@ -80,16 +80,16 @@
 
 	user.put_in_hands(released_paper)
 
-/obj/item/paperplane/attackby(obj/item/attacking_item, mob/user, list/modifiers, list/attack_modifiers)
-	if(IS_WRITING_UTENSIL(attacking_item))
+/obj/item/paperplane/item_interaction(mob/living/user, obj/item/tool, list/modifiers)
+	if(IS_WRITING_UTENSIL(tool))
 		to_chat(user, span_warning("You should unfold [src] before changing it!"))
-		return
-	else if(istype(attacking_item, /obj/item/stamp)) //we don't randomize stamps on a paperplane
-		internal_paper.attackby(attacking_item, user) //spoofed attack to update internal paper.
+		return ITEM_INTERACT_BLOCKING
+	if(istype(tool, /obj/item/stamp)) //we don't randomize stamps on a paperplane
+		internal_paper.item_interaction(user, tool) //spoofed attack to update internal paper.
 		update_appearance()
 		add_fingerprint(user)
-		return
-	return ..()
+		return ITEM_INTERACT_SUCCESS
+	return NONE
 
 /obj/item/paperplane/throw_impact(atom/hit_atom, datum/thrownthing/throwingdatum)
 	if(iscarbon(hit_atom) && HAS_TRAIT(hit_atom, TRAIT_PAPER_MASTER))

code/modules/paperwork/paperwork.dm

@@ -39,27 +39,27 @@
 
 	detailed_desc = span_notice("<i>As you sift through the papers, you slowly start to piece together what you're reading.</i>")
 
-/obj/item/paperwork/attackby(obj/item/attacking_item, mob/user, list/modifiers, list/attack_modifiers)
-	. = ..()
-	if(.)
-		return
+/obj/item/paperwork/item_interaction(mob/living/user, obj/item/tool, list/modifiers)
+	if(!istype(tool, /obj/item/stamp))
+		return NONE
 
-	if(stamped || !istype(attacking_item, /obj/item/stamp))
-		return
+	if(stamped)
+		return ITEM_INTERACT_BLOCKING
 
-	if(istype(attacking_item, stamp_requested))
+	if(istype(tool, stamp_requested))
 		add_stamp()
 		to_chat(user, span_notice("You skim through the papers until you find a field reading 'STAMP HERE', and complete the paperwork."))
-		return TRUE
-	var/datum/action/item_action/chameleon/change/stamp/stamp_action = locate() in attacking_item.actions
-	if(isnull(stamp_action))
-		to_chat(user, span_warning("You hunt through the papers for somewhere to use [attacking_item], but can't find anything."))
-		return TRUE
+		return ITEM_INTERACT_SUCCESS
 
-	to_chat(user, span_notice("[attacking_item] morphs into the appropriate stamp, which you use to complete the paperwork."))
+	var/datum/action/item_action/chameleon/change/stamp/stamp_action = locate() in tool.actions
+	if(isnull(stamp_action))
+		to_chat(user, span_warning("You hunt through the papers for somewhere to use [tool], but can't find anything."))
+		return ITEM_INTERACT_BLOCKING
+
+	to_chat(user, span_notice("[tool] morphs into the appropriate stamp, which you use to complete the paperwork."))
 	stamp_action.update_look(stamp_requested)
 	add_stamp()
-	return TRUE
+	return ITEM_INTERACT_SUCCESS
 
 /obj/item/paperwork/examine_more(mob/user)
 	. = ..()
@@ -233,16 +233,15 @@
 	else
 		. += span_notice("These appear to just be a photocopy of the original documents.")
 
-/obj/item/paperwork/photocopy/attackby(obj/item/attacking_item, mob/user, list/modifiers, list/attack_modifiers)
-	if(istype(attacking_item, /obj/item/stamp/void) && !stamped && !voided)
-		to_chat(user, span_notice("You plant the [attacking_item] firmly onto the front of the documents."))
-		stamp_overlay = mutable_appearance('icons/obj/service/bureaucracy.dmi', "paper_stamp-void")
-		add_overlay(stamp_overlay)
-		voided = TRUE
-		stamped = TRUE //It won't get you any money, but it also can't LOSE you money now.
-		return
-
-	return ..()
+/obj/item/paperwork/photocopy/item_interaction(mob/living/user, obj/item/tool, list/modifiers)
+	if(!istype(tool, /obj/item/stamp/void) || stamped || voided)
+		return ..()
+	to_chat(user, span_notice("You plant the [tool] firmly onto the front of the documents."))
+	stamp_overlay = mutable_appearance('icons/obj/service/bureaucracy.dmi', "paper_stamp-void")
+	add_overlay(stamp_overlay)
+	voided = TRUE
+	stamped = TRUE //It won't get you any money, but it also can't LOSE you money now.
+	return ITEM_INTERACT_SUCCESS
 
 //Ancient paperwork is a subtype of paperwork, meant to be used for any paperwork not spawned by the event.
 //It doesn't have any of the flavor text that the event ones spawn with.

code/modules/paperwork/ticketmachine.dm

@@ -178,26 +178,30 @@ MAPPING_DIRECTIONAL_HELPERS(/obj/machinery/ticket_machine, 32)
 			maptext_x = 4
 	maptext = MAPTEXT(current_number) //Finally, apply the maptext
 
-/obj/machinery/ticket_machine/attackby(obj/item/I, mob/user, list/modifiers, list/attack_modifiers)
-	..()
-	if(istype(I, /obj/item/hand_labeler_refill))
-		if(!(ticket_number >= max_number))
-			to_chat(user, span_notice("[src] refuses [I]! There [max_number - ticket_number == 1 ? "is" : "are"] still [max_number - ticket_number] ticket\s left!"))
-			return
-		to_chat(user, span_notice("You start to refill [src]'s ticket holder (doing this will reset its ticket count!)."))
-		if(do_after(user, 3 SECONDS, target = src))
-			to_chat(user, span_notice("You insert [I] into [src] as it whirs nondescriptly."))
-			qdel(I)
-			ticket_number = 0
-			current_number = 0
-			if(tickets.len)
-				for(var/obj/item/ticket_machine_ticket/ticket in tickets)
-					ticket.audible_message(span_notice("\the [ticket] disperses!"), hearing_distance = SAMETILE_MESSAGE_RANGE)
-					qdel(ticket)
-				tickets.Cut()
-			max_number = initial(max_number)
-			update_appearance()
-			return
+/obj/machinery/ticket_machine/item_interaction(mob/living/user, obj/item/tool, list/modifiers)
+	if(!istype(tool, /obj/item/hand_labeler_refill))
+		return NONE
+
+	if(!(ticket_number >= max_number))
+		to_chat(user, span_notice("[src] refuses [tool]! There [max_number - ticket_number == 1 ? "is" : "are"] still [max_number - ticket_number] ticket\s left!"))
+		return ITEM_INTERACT_BLOCKING
+
+	to_chat(user, span_notice("You start to refill [src]'s ticket holder (doing this will reset its ticket count!)."))
+	if(!do_after(user, 3 SECONDS, target = src))
+		return ITEM_INTERACT_BLOCKING
+
+	to_chat(user, span_notice("You insert [tool] into [src] as it whirs nondescriptly."))
+	qdel(tool)
+	ticket_number = 0
+	current_number = 0
+	if(tickets.len)
+		for(var/obj/item/ticket_machine_ticket/ticket in tickets)
+			ticket.audible_message(span_notice("\the [ticket] disperses!"), hearing_distance = SAMETILE_MESSAGE_RANGE)
+			qdel(ticket)
+		tickets.Cut()
+	max_number = initial(max_number)
+	update_appearance()
+	return ITEM_INTERACT_SUCCESS
 
 /obj/machinery/ticket_machine/proc/reset_cooldown()
 	ready = TRUE

code/modules/photography/photos/frame.dm

@@ -12,16 +12,17 @@
 	var/obj/item/photo/displayed
 	pixel_shift = 30
 
-/obj/item/wallframe/picture/attackby(obj/item/I, mob/user)
-	if(istype(I, /obj/item/photo))
-		if(!displayed)
-			if(!user.transferItemToLoc(I, src))
-				return
-			displayed = I
-			update_appearance()
-		else
-			to_chat(user, span_warning("\The [src] already contains a photo."))
-	..()
+/obj/item/wallframe/picture/item_interaction(mob/living/user, obj/item/tool, list/modifiers)
+	if(!istype(tool, /obj/item/photo))
+		return NONE
+	if(displayed)
+		to_chat(user, span_warning("\The [src] already contains a photo."))
+		return ITEM_INTERACT_BLOCKING
+	if(!user.transferItemToLoc(tool, src))
+		return ITEM_INTERACT_BLOCKING
+	displayed = tool
+	update_appearance()
+	return ITEM_INTERACT_SUCCESS
 
 //ATTACK HAND IGNORING PARENT RETURN VALUE
 /obj/item/wallframe/picture/attack_hand(mob/user, list/modifiers)
@@ -145,19 +146,17 @@
 	return ITEM_INTERACT_SUCCESS
 
 
-/obj/structure/sign/picture_frame/attackby(obj/item/I, mob/user, list/modifiers, list/attack_modifiers)
-
-	if(istype(I, /obj/item/photo))
-		if(framed)
-			to_chat(user, span_warning("\The [src] already contains a photo."))
-			return TRUE
-		var/obj/item/photo/P = I
-		if(!user.transferItemToLoc(P, src))
-			return
-		set_and_save_framed(P)
-		update_appearance()
-		return TRUE
-	..()
+/obj/structure/sign/picture_frame/item_interaction(mob/living/user, obj/item/tool, list/modifiers)
+	if(!istype(tool, /obj/item/photo))
+		return NONE
+	if(framed)
+		to_chat(user, span_warning("\The [src] already contains a photo."))
+		return ITEM_INTERACT_BLOCKING
+	if(!user.transferItemToLoc(tool, src))
+		return ITEM_INTERACT_BLOCKING
+	set_and_save_framed(tool)
+	update_appearance()
+	return ITEM_INTERACT_SUCCESS
 
 /obj/structure/sign/picture_frame/attack_hand(mob/user, list/modifiers)
 	. = ..()

code/modules/photography/photos/photo.dm

@@ -79,16 +79,17 @@
 /obj/item/photo/attack_self(mob/user)
 	user.examinate(src)
 
-/obj/item/photo/attackby(obj/item/P, mob/user, list/modifiers, list/attack_modifiers)
-	if(IS_WRITING_UTENSIL(P))
-		if(!user.can_write(P))
-			return
-		var/txt = tgui_input_text(user, "What would you like to write on the back?", "Photo Writing", max_length = 128)
-		if(txt && user.can_perform_action(src))
-			playsound(src, SFX_WRITING_PEN, 50, TRUE, SHORT_RANGE_SOUND_EXTRARANGE, SOUND_FALLOFF_EXPONENT + 3, ignore_walls = FALSE)
-			scribble = txt
-	else
-		return ..()
+/obj/item/photo/item_interaction(mob/living/user, obj/item/tool, list/modifiers)
+	if(!IS_WRITING_UTENSIL(tool))
+		return NONE
+	if(!user.can_write(tool))
+		return ITEM_INTERACT_BLOCKING
+	var/txt = tgui_input_text(user, "What would you like to write on the back?", "Photo Writing", max_length = 128)
+	if(!txt || !user.can_perform_action(src))
+		return ITEM_INTERACT_BLOCKING
+	playsound(src, SFX_WRITING_PEN, 50, TRUE, SHORT_RANGE_SOUND_EXTRARANGE, SOUND_FALLOFF_EXPONENT + 3, ignore_walls = FALSE)
+	scribble = txt
+	return ITEM_INTERACT_SUCCESS
 
 /obj/item/photo/examine(mob/user)
 	. = ..()

code/modules/power/power.dm

@@ -324,18 +324,17 @@
 
 // attach a wire to a power machine - leads from the turf you are standing on
 //almost never called, overwritten by all power machines but terminal and generator
-/obj/machinery/power/attackby(obj/item/W, mob/user, list/modifiers, list/attack_modifiers)
-	if(istype(W, /obj/item/stack/cable_coil))
-		var/obj/item/stack/cable_coil/coil = W
-		var/turf/T = user.loc
-		if(T.underfloor_accessibility < UNDERFLOOR_INTERACTABLE || !isfloorturf(T))
-			return
-		if(get_dist(src, user) > 1)
-			return
-		coil.place_turf(T, user)
-	else
-		return ..()
-
+/obj/machinery/power/item_interaction(mob/living/user, obj/item/tool, list/modifiers)
+	if(!istype(tool, /obj/item/stack/cable_coil))
+		return NONE
+	var/obj/item/stack/cable_coil/coil = tool
+	var/turf/userturf = user.loc
+	if(userturf.underfloor_accessibility < UNDERFLOOR_INTERACTABLE || !isfloorturf(userturf))
+		return ITEM_INTERACT_BLOCKING
+	if(get_dist(src, user) > 1)
+		return ITEM_INTERACT_BLOCKING
+	coil.place_turf(userturf, user)
+	return ITEM_INTERACT_SUCCESS
 
 ///////////////////////////////////////////
 // Powernet handling helpers