diff --git a/code/game/machinery/doors/airlock.dm b/code/game/machinery/doors/airlock.dm
index a089f57f31b..244484d8a84 100644
--- a/code/game/machinery/doors/airlock.dm
+++ b/code/game/machinery/doors/airlock.dm
@@ -161,6 +161,13 @@
 	var/insecure = TRUE
 	var/securitylock = FALSE
 
+	/// Override access by code level. This is an associative list that should only be set through /obj/effect/map_effect/door_helper/level_access.
+	/// Structure example: "red" -> list(1, 2)
+	/// Uses standard access if the current level is not on the list.
+	var/list/access_by_level
+	/// As above, but with req_one_access. Note that only one of these lists should ever be set.
+	var/list/req_one_access_by_level
+
 /obj/machinery/door/airlock/Initialize(mapload, dir, populate_components, obj/structure/door_assembly/assembly = null)
 	var/on_admin_z = FALSE
 	//wires & hatch - this needs to be done up here so the hatch isn't generated by the parent Initialize().
@@ -2064,6 +2071,8 @@ About the new airlock wires panel:
 		to_chat(user, bracer.health)
 	if(p_open)
 		to_chat(user, "\The [src]'s maintenance panel has been unscrewed and is hanging open.")
+	if(islist(access_by_level) || islist(req_one_access_by_level))
+		to_chat(user, SPAN_NOTICE("This airlock changes access requirements depending on the level."))
 
 /obj/machinery/door/airlock/emag_act(var/remaining_charges)
 	. = ..()
diff --git a/code/modules/effects/map_effects/door_helper.dm b/code/modules/effects/map_effects/door_helper.dm
index b886a5315d9..40568594e25 100644
--- a/code/modules/effects/map_effects/door_helper.dm
+++ b/code/modules/effects/map_effects/door_helper.dm
@@ -1,13 +1,44 @@
 /obj/effect/map_effect/door_helper
 	layer = DOOR_CLOSED_LAYER + 0.1
 
-/obj/effect/map_effect/door_helper/unres
-	icon_state = "unres_door"
-
-/obj/effect/map_effect/door_helper/unres/Initialize(mapload, ...)
+/obj/effect/map_effect/door_helper/Initialize(mapload, ...)
 	..()
 	for(var/obj/machinery/door/D in loc)
 		if(istype(D, /obj/machinery/door/blast) || istype(D, /obj/machinery/door/firedoor))
 			continue
-		D.unres_dir ^= dir
+		modify_door(D)
 	return INITIALIZE_HINT_QDEL
+
+/obj/effect/map_effect/door_helper/proc/modify_door(obj/machinery/door/D)
+	return
+
+/obj/effect/map_effect/door_helper/unres
+	icon_state = "unres_door"
+
+/obj/effect/map_effect/door_helper/unres/modify_door(obj/machinery/door/D)
+	D.unres_dir ^= dir
+
+/obj/effect/map_effect/door_helper/level_access
+	icon_state = "level_door"
+
+	/// Sets access_by_level (access override based on security level) on the airlock this is spawned on.
+	/// For more information check the access_by_level variable on the airlock.
+	/// Example of an appropriate way to set this: list("red" = list(1, 2))
+	/// Alternatively, for a door that is free access on a certain code: list("green" = null)
+	var/list/access_by_level
+	/// As above, but with req_one_access. Note that only one of these lists should ever be set.
+	var/list/req_one_access_by_level
+
+/obj/effect/map_effect/door_helper/level_access/modify_door(obj/machinery/door/D)
+	if(length(access_by_level) && length(req_one_access_by_level))
+		crash_with("Airlock access level modifier at [x] [y] [z] spawned with both access lists set.")
+	if(isairlock(D))
+		var/obj/machinery/door/airlock/A = D
+		A.access_by_level = access_by_level
+		A.req_one_access_by_level = req_one_access_by_level
+
+/obj/effect/map_effect/door_helper/level_access/test1
+	access_by_level = list("green" = list(access_security))
+
+/obj/effect/map_effect/door_helper/level_access/test2
+	req_one_access_by_level = list("green" = list(access_security, access_heads))
diff --git a/code/modules/security levels/keycard authentication.dm b/code/modules/security levels/keycard authentication.dm
index bc72bf02b05..7028615d914 100644
--- a/code/modules/security levels/keycard authentication.dm	
+++ b/code/modules/security levels/keycard authentication.dm	
@@ -221,4 +221,16 @@ var/global/maint_all_access = 0
 	var/exceptional_circumstances = maint_all_access || maint_sec_access
 	if(exceptional_circumstances && src.check_access_list(list(access_maint_tunnels)))
 		return 1
+	if(access_by_level || req_one_access_by_level)
+		var/sec_level = get_security_level()
+		if(sec_level in (req_one_access_by_level ? req_one_access_by_level : access_by_level))
+			var/access_to_use = req_one_access_by_level ? req_one_access_by_level[sec_level] : access_by_level[sec_level]
+			if(!access_to_use)
+				return TRUE
+			if(req_one_access_by_level)
+				if(has_access(req_one_access = access_to_use, accesses = A))
+					return TRUE
+			else
+				if(has_access(access_to_use, accesses = A))
+					return TRUE
 	return ..(M)
diff --git a/html/changelogs/mattatlas-doorsbylevel.yml b/html/changelogs/mattatlas-doorsbylevel.yml
new file mode 100644
index 00000000000..0ce60b38c2e
--- /dev/null
+++ b/html/changelogs/mattatlas-doorsbylevel.yml
@@ -0,0 +1,42 @@
+################################
+# Example Changelog File
+#
+# Note: This file, and files beginning with ".", and files that don't end in ".yml" will not be read. If you change this file, you will look really dumb.
+#
+# Your changelog will be merged with a master changelog. (New stuff added only, and only on the date entry for the day it was merged.)
+# When it is, any changes listed below will disappear.
+#
+# Valid Prefixes:
+#   bugfix
+#   wip (For works in progress)
+#   tweak
+#   soundadd
+#   sounddel
+#   rscadd (general adding of nice things)
+#   rscdel (general deleting of nice things)
+#   imageadd
+#   imagedel
+#   maptweak
+#   spellcheck (typo fixes)
+#   experiment
+#   balance
+#   admin
+#   backend
+#   security
+#   refactor
+#################################
+
+# Your name.
+author: MattAtlas
+
+# Optional: Remove this file after generating master changelog.  Useful for PR changelogs that won't get used again.
+delete-after: True
+
+# Any changes you've made.  See valid prefix list above.
+# INDENT WITH TWO SPACES.  NOT TABS.  SPACES.
+# SCREW THIS UP AND IT WON'T WORK.
+# Also, all entries are changed into a single [] after a master changelog generation. Just remove the brackets when you add new entries.
+# Please surround your changes in  double quotes ("), as certain characters otherwise screws up compiling. The quotes will not show up in the changelog.
+changes:
+  - rscadd: "Added a changelog editing system that should cause fewer conflicts and more accurate timestamps."
+  - rscdel: "Killed innocent kittens."
diff --git a/icons/effects/map_effects.dmi b/icons/effects/map_effects.dmi
index 9080a1fc9f4..bcfe5c600b8 100644
Binary files a/icons/effects/map_effects.dmi and b/icons/effects/map_effects.dmi differ