diff --git a/code/__HELPERS/traits.dm b/code/__HELPERS/traits.dm
index 922200948bb..efe5a33b3da 100644
--- a/code/__HELPERS/traits.dm
+++ b/code/__HELPERS/traits.dm
@@ -199,6 +199,7 @@ Remember to update _globalvars/traits.dm if you're adding/removing/renaming trai
 /// Show what machine/door wires do when held.
 #define TRAIT_SHOW_WIRE_INFO "show_wire_info"
 #define TRAIT_BUTCHERS_HUMANS "butchers_humans"
+#define TRAIT_CMAGGED "cmagged"
 
 //
 // common trait sources
diff --git a/code/_globalvars/traits.dm b/code/_globalvars/traits.dm
index fa009ae3102..015cfe38f2a 100644
--- a/code/_globalvars/traits.dm
+++ b/code/_globalvars/traits.dm
@@ -71,7 +71,8 @@ GLOBAL_LIST_INIT(traits_by_type, list(
 	),
 	/obj/item = list(
 		"TRAIT_SHOW_WIRE_INFO" = TRAIT_SHOW_WIRE_INFO,
-		"TRAIT_BUTCHER_HUMANS" = TRAIT_BUTCHERS_HUMANS
+		"TRAIT_BUTCHER_HUMANS" = TRAIT_BUTCHERS_HUMANS,
+		"TRAIT_CMAGGED" = TRAIT_CMAGGED
 	)
 ))
 
diff --git a/code/datums/uplink_item.dm b/code/datums/uplink_item.dm
index c394b3c37fc..4d61e94048a 100644
--- a/code/datums/uplink_item.dm
+++ b/code/datums/uplink_item.dm
@@ -182,6 +182,15 @@ GLOBAL_LIST_INIT(uplink_items, subtypesof(/datum/uplink_item))
 	surplus = 75
 	job = list("Clown")
 
+/datum/uplink_item/jobspecific/cmag
+	name = "Jestographic Sequencer"
+	desc = "The jestographic sequencer, also known as a cmag, is a small card that inverts the access on any door it's used on. Perfect for locking command out of their own departments. Honk!"
+	reference = "CMG"
+	item = /obj/item/card/cmag
+	cost = 4
+	surplus = 75
+	job = list("Clown")
+
 /datum/uplink_item/jobspecific/trick_revolver
 	name = "Trick Revolver"
 	desc = "A revolver that will fire backwards and kill whoever attempts to use it. Perfect for those pesky vigilante or just a good laugh."
diff --git a/code/game/atoms.dm b/code/game/atoms.dm
index 90848fc9a12..8e941dfd4bb 100644
--- a/code/game/atoms.dm
+++ b/code/game/atoms.dm
@@ -423,7 +423,7 @@
 	SHOULD_CALL_PARENT(TRUE)
 
 	if(updates & NONE)
-		return // NONE is being sent on purpose, and thus no signal should be sent. 
+		return // NONE is being sent on purpose, and thus no signal should be sent.
 
 	updates &= ~SEND_SIGNAL(src, COMSIG_ATOM_UPDATE_ICON, updates)
 	if(updates & UPDATE_ICON_STATE)
@@ -514,6 +514,9 @@
 /atom/proc/unemag()
 	return
 
+/atom/proc/cmag_act()
+	return
+
 /**
  * Respond to a radioactive wave hitting this atom
  *
diff --git a/code/game/machinery/doors/airlock.dm b/code/game/machinery/doors/airlock.dm
index 54b52dade9c..9d6f100ad6c 100644
--- a/code/game/machinery/doors/airlock.dm
+++ b/code/game/machinery/doors/airlock.dm
@@ -605,6 +605,8 @@ GLOBAL_LIST_EMPTY(airlock_emissive_underlays)
 	. = ..()
 	if(emagged)
 		. += "<span class='warning'>Its access panel is smoking slightly.</span>"
+	if(HAS_TRAIT(src, TRAIT_CMAGGED))
+		. += "<span class='warning'>The access panel is coated in yellow ooze...</span>"
 	if(note)
 		if(!in_range(user, src))
 			. += "There's a [note.name] pinned to the front. You can't [note_type() == "note" ? "read" : "see"] it from here."
@@ -802,7 +804,7 @@ GLOBAL_LIST_EMPTY(airlock_emissive_underlays)
 /obj/machinery/door/airlock/proc/ai_control_check(mob/user)
 	if(!issilicon(user))
 		return TRUE
-	if(emagged)
+	if(emagged || HAS_TRAIT(src, TRAIT_CMAGGED))
 		to_chat(user, "<span class='warning'>Unable to interface: Internal error.</span>")
 		return FALSE
 	if(!canAIControl())
@@ -1336,6 +1338,19 @@ GLOBAL_LIST_EMPTY(airlock_emissive_underlays)
 		emagged = TRUE
 		return 1
 
+/obj/machinery/door/airlock/cmag_act(mob/user)
+	if(operating || HAS_TRAIT(src, TRAIT_CMAGGED) || !density || !arePowerSystemsOn())
+		return
+	operating = TRUE
+	update_icon(AIRLOCK_EMAG, 1)
+	sleep(6)
+	if(QDELETED(src))
+		return
+	operating = FALSE
+	update_icon(AIRLOCK_CLOSED, 1)
+	ADD_TRAIT(src, TRAIT_CMAGGED, "clown_emag")
+	return TRUE
+
 /obj/machinery/door/airlock/emp_act(severity)
 	. = ..()
 	if(prob(20 / severity))
diff --git a/code/game/machinery/doors/door.dm b/code/game/machinery/doors/door.dm
index 289e0098b21..c6f82284212 100644
--- a/code/game/machinery/doors/door.dm
+++ b/code/game/machinery/doors/door.dm
@@ -36,6 +36,9 @@
 	var/unres_sides = 0
 	//Multi-tile doors
 	var/width = 1
+	//Whether nonstandard door sounds (cmag laughter) are off cooldown.
+	var/sound_ready = TRUE
+	var/sound_cooldown = 1 SECONDS
 
 	/// ID for the window tint button, or another external control
 	var/id
@@ -116,8 +119,14 @@
 				if(world.time - mecha.occupant.last_bumped <= 10)
 					return
 			if(mecha.occupant && allowed(mecha.occupant) || check_access_list(mecha.operation_req_access))
+				if(HAS_TRAIT(src, TRAIT_CMAGGED))
+					cmag_switch(FALSE, mecha.occupant)
+					return
 				open()
 			else
+				if(HAS_TRAIT(src, TRAIT_CMAGGED))
+					cmag_switch(TRUE, mecha.occupant)
+					return
 				do_animate("deny")
 		return
 
@@ -149,6 +158,9 @@
 
 	if(density && !emagged)
 		if(allowed(user))
+			if(HAS_TRAIT(src, TRAIT_CMAGGED))
+				cmag_switch(FALSE, user)
+				return
 			open()
 			if(isbot(user))
 				var/mob/living/simple_animal/bot/B = user
@@ -156,6 +168,9 @@
 		else
 			if(pry_open_check(user))
 				return
+			if(HAS_TRAIT(src, TRAIT_CMAGGED))
+				cmag_switch(TRUE, user)
+				return
 			do_animate("deny")
 
 /obj/machinery/door/proc/pry_open_check(mob/user)
@@ -204,10 +219,18 @@
 		return
 	if(requiresID() && (allowed(user) || user.can_advanced_admin_interact()))
 		if(density)
+			if(HAS_TRAIT(src, TRAIT_CMAGGED) && !user.can_advanced_admin_interact()) //cmag should not prevent admin intervention
+				cmag_switch(FALSE, user)
+				return
 			open()
 		else
+			if(HAS_TRAIT(src, TRAIT_CMAGGED) && !user.can_advanced_admin_interact())
+				return
 			close()
 		return TRUE
+	if(HAS_TRAIT(src, TRAIT_CMAGGED))
+		cmag_switch(TRUE, user)
+		return
 	if(density)
 		do_animate("deny")
 
@@ -226,7 +249,28 @@
 /obj/machinery/door/proc/try_to_crowbar(mob/user, obj/item/I)
 	return
 
+/obj/machinery/door/proc/clean_cmag_ooze(obj/item/I, mob/user) //Emags are Engineering's problem, cmags are the janitor's problem
+	var/cleaning = FALSE
+	if(istype(I, /obj/item/reagent_containers/spray/cleaner))
+		var/obj/item/reagent_containers/spray/cleaner/C = I
+		if(C.reagents.total_volume >= C.amount_per_transfer_from_this)
+			cleaning = TRUE
+		else
+			return
+	if(istype(I, /obj/item/soap))
+		cleaning = TRUE
+
+	if(!cleaning)
+		return
+	user.visible_message("<span class='notice'>[user] starts to clean the ooze off the access panel.</span>", "<span class='notice'>You start to clean the ooze off the access panel.</span>")
+	if(do_after(user, 50, target = src))
+		user.visible_message("<span class='notice'>[user] cleans the ooze off [src].</span>", "<span class='notice'>You clean the ooze off [src].</span>")
+		REMOVE_TRAIT(src, TRAIT_CMAGGED, "clown_emag")
+
 /obj/machinery/door/attackby(obj/item/I, mob/user, params)
+	if(HAS_TRAIT(src, TRAIT_CMAGGED))
+		clean_cmag_ooze(I, user)
+
 	if(user.a_intent != INTENT_HARM && istype(I, /obj/item/twohanded/fireaxe))
 		try_to_crowbar(user, I)
 		return 1
@@ -235,7 +279,6 @@
 		return 1
 	return ..()
 
-
 /obj/machinery/door/crowbar_act(mob/user, obj/item/I)
 	if(user.a_intent == INTENT_HARM)
 		return
@@ -272,6 +315,46 @@
 		emagged = TRUE
 		return TRUE
 
+/obj/machinery/door/cmag_act(mob/user)
+	if(!density)
+		return
+	flick("door_spark", src)
+	sleep(6) //The cmag doesn't automatically open doors. It inverts access, not provides it!
+	ADD_TRAIT(src, TRAIT_CMAGGED, "clown_emag")
+	return TRUE
+
+//Proc for inverting access on cmagged doors."canopen" should always return the OPPOSITE of the normal result.
+/obj/machinery/door/proc/cmag_switch(canopen, mob/living/user)
+	if(!canopen || locked || !hasPower())
+		if(density) //Windoors can still do their deny animation in unpowered environments, this bugs out if density isn't checked for
+			do_animate("deny")
+		if(hasPower() && sound_ready)
+			playsound(loc, 'sound/machines/honkbot_evil_laugh.ogg', 25, TRUE, ignore_walls = FALSE)
+			soundcooldown()
+		return
+	if(ishuman(user))
+		var/mob/living/carbon/human/H = user
+		var/obj/item/card/id/idcard = H.get_idcard()
+		if(!idcard?.assignment) //Humans can't game inverted access by taking their ID off or using spare IDs.
+			if(!density)
+				return
+			do_animate("deny")
+			to_chat(H, "<span class='warning'>The airlock speaker chuckles: 'What's wrong, pal? Lost your ID? Nyuk nyuk nyuk!'</span>")
+			if(sound_ready)
+				playsound(loc, 'sound/machines/honkbot_evil_laugh.ogg', 25, TRUE, ignore_walls = FALSE)
+				soundcooldown() //Thanks, mechs
+			return
+	if(density)
+		open()
+	else
+		close()
+
+/obj/machinery/door/proc/soundcooldown()
+	if(!sound_ready)
+		return
+	sound_ready = FALSE
+	addtimer(VARSET_CALLBACK(src, sound_ready, TRUE), sound_cooldown)
+
 /obj/machinery/door/proc/toggle_polarization()
 	return
 
diff --git a/code/game/machinery/doors/windowdoor.dm b/code/game/machinery/doors/windowdoor.dm
index 07e4d7a5a26..14b3fdcc979 100644
--- a/code/game/machinery/doors/windowdoor.dm
+++ b/code/game/machinery/doors/windowdoor.dm
@@ -62,6 +62,8 @@
 	. = ..()
 	if(emagged)
 		. += "<span class='warning'>Its access panel is smoking slightly.</span>"
+	if(HAS_TRAIT(src, TRAIT_CMAGGED))
+		. += "<span class='warning'>The access panel is coated in yellow ooze...</span>"
 
 /obj/machinery/door/window/emp_act(severity)
 	. = ..()
@@ -83,8 +85,14 @@
 		if(ismecha(AM))
 			var/obj/mecha/mecha = AM
 			if(mecha.occupant && allowed(mecha.occupant))
+				if(HAS_TRAIT(src, TRAIT_CMAGGED))
+					cmag_switch(FALSE)
+					return
 				open_and_close()
 			else
+				if(HAS_TRAIT(src, TRAIT_CMAGGED))
+					cmag_switch(TRUE)
+					return
 				do_animate("deny")
 		return
 	if(!SSticker)
@@ -98,8 +106,14 @@
 		return
 	add_fingerprint(user)
 	if(!requiresID() || allowed(user))
+		if(HAS_TRAIT(src, TRAIT_CMAGGED))
+			cmag_switch(FALSE, user)
+			return
 		open_and_close()
 	else
+		if(HAS_TRAIT(src, TRAIT_CMAGGED))
+			cmag_switch(TRUE, user)
+			return
 		do_animate("deny")
 
 /obj/machinery/door/window/unrestricted_side(mob/M)
@@ -247,6 +261,17 @@
 		open(2)
 		return 1
 
+/obj/machinery/door/window/cmag_act(mob/user, obj/weapon)
+	if(operating || !density || HAS_TRAIT(src, TRAIT_CMAGGED))
+		return
+	ADD_TRAIT(src, TRAIT_CMAGGED, "clown_emag")
+	operating = TRUE
+	flick("[base_state]spark", src)
+	playsound(src, "sparks", 75, TRUE, SHORT_RANGE_SOUND_EXTRARANGE)
+	sleep(6)
+	operating = FALSE
+	return TRUE
+
 /obj/machinery/door/window/attackby(obj/item/I, mob/living/user, params)
 	//If it's in the process of opening/closing, ignore the click
 	if(operating)
diff --git a/code/game/objects/items/control_wand.dm b/code/game/objects/items/control_wand.dm
index cb347fe9105..a0235f9f4a7 100644
--- a/code/game/objects/items/control_wand.dm
+++ b/code/game/objects/items/control_wand.dm
@@ -48,6 +48,9 @@
 /obj/item/door_remote/afterattack(obj/machinery/door/airlock/D, mob/user)
 	if(!istype(D))
 		return
+	if(HAS_TRAIT(D, TRAIT_CMAGGED))
+		to_chat(user, "<span class='danger'>The door doesn't respond to [src]!</span>")
+		return
 	if(D.is_special)
 		to_chat(user, "<span class='danger'>[src] cannot access this kind of door!</span>")
 		return
diff --git a/code/game/objects/items/weapons/cards_ids.dm b/code/game/objects/items/weapons/cards_ids.dm
index 62e54e713e8..082ad69ca61 100644
--- a/code/game/objects/items/weapons/cards_ids.dm
+++ b/code/game/objects/items/weapons/cards_ids.dm
@@ -80,6 +80,27 @@
 		return
 	A.emag_act(user)
 
+/obj/item/card/cmag
+	desc = "It's a card coated in a slurry of electromagnetic bananium."
+	name = "jestographic sequencer"
+	icon_state = "cmag"
+	item_state = "card-id"
+	origin_tech = "magnets=2;syndicate=2"
+	flags = NOBLUDGEON
+	flags_2 = NO_MAT_REDEMPTION_2
+
+/obj/item/card/cmag/Initialize(mapload)
+	. = ..()
+	AddComponent(/datum/component/slippery, src, 16 SECONDS, 100)
+
+/obj/item/card/cmag/attack()
+	return
+
+/obj/item/card/cmag/afterattack(atom/target, mob/user, proximity)
+	if(!proximity)
+		return
+	target.cmag_act(user)
+
 /obj/item/card/id
 	name = "identification card"
 	desc = "A card used to provide ID and determine access across the station."
diff --git a/icons/obj/card.dmi b/icons/obj/card.dmi
index f51593e0216..41882bb12c0 100644
Binary files a/icons/obj/card.dmi and b/icons/obj/card.dmi differ