diff --git a/code/game/jobs/job/science.dm b/code/game/jobs/job/science.dm
index eaa1c4b7936..1f69a5ee14d 100644
--- a/code/game/jobs/job/science.dm
+++ b/code/game/jobs/job/science.dm
@@ -133,33 +133,3 @@
 		H.equip_to_slot_or_del(new /obj/item/weapon/storage/belt/utility/full(H), slot_belt)
 		H.equip_to_slot_or_del(new /obj/item/clothing/suit/storage/toggle/labcoat(H), slot_wear_suit)
 		return TRUE
-
-/datum/job/geneticist
-	title = "Geneticist"
-	flag = GENETICIST
-	department = "Science"
-	department_flag = MEDSCI
-	faction = "Station"
-	total_positions = 0
-	spawn_positions = 0
-	supervisors = "the research director"
-	selection_color = "#ffeeff"
-	economic_modifier = 7
-	access = list(access_genetics, access_tox, access_tox_storage, access_morgue, access_research)
-	minimal_access = list(access_morgue, access_genetics, access_research)
-
-	bag_type = /obj/item/weapon/storage/backpack/genetics
-	satchel_type = /obj/item/weapon/storage/backpack/satchel_gen
-	duffel_type = /obj/item/weapon/storage/backpack/duffel/gen
-	messenger_bag_type = /obj/item/weapon/storage/backpack/messenger/gen
-
-	equip(var/mob/living/carbon/human/H)
-		if(!H)
-			return FALSE
-		H.equip_to_slot_or_del(new /obj/item/device/radio/headset/headset_sci(H), slot_l_ear)
-		H.equip_to_slot_or_del(new /obj/item/clothing/under/rank/geneticist(H), slot_w_uniform)
-		H.equip_to_slot_or_del(new /obj/item/clothing/shoes/white(H), slot_shoes)
-		H.equip_to_slot_or_del(new /obj/item/device/pda/geneticist(H), slot_belt)
-		H.equip_to_slot_or_del(new /obj/item/clothing/suit/storage/toggle/labcoat/genetics(H), slot_wear_suit)
-		H.equip_to_slot_or_del(new /obj/item/device/flashlight/pen(H), slot_s_store)
-		return TRUE
diff --git a/code/game/jobs/jobs.dm b/code/game/jobs/jobs.dm
index 8736fa16874..c7c84264c75 100644
--- a/code/game/jobs/jobs.dm
+++ b/code/game/jobs/jobs.dm
@@ -23,14 +23,13 @@ var/const/SCIENTIST			=(1<<1)
 var/const/CHEMIST			=(1<<2)
 var/const/CMO				=(1<<3)
 var/const/DOCTOR			=(1<<4)
-var/const/GENETICIST		=(1<<5)
-var/const/VIROLOGIST		=(1<<6)
-var/const/PSYCHIATRIST		=(1<<7)
-var/const/ROBOTICIST		=(1<<8)
-var/const/XENOBIOLOGIST		=(1<<9)
-var/const/PARAMEDIC			=(1<<10)
-var/const/INTERN_MED		=(1<<11)
-var/const/INTERN_SCI		=(1<<12)
+var/const/VIROLOGIST		=(1<<5)
+var/const/PSYCHIATRIST		=(1<<6)
+var/const/ROBOTICIST		=(1<<7)
+var/const/XENOBIOLOGIST		=(1<<8)
+var/const/PARAMEDIC			=(1<<9)
+var/const/INTERN_MED		=(1<<10)
+var/const/INTERN_SCI		=(1<<11)
 
 var/const/CIVILIAN			=(1<<2)
 
@@ -85,7 +84,6 @@ var/list/medical_positions = list(
 var/list/science_positions = list(
 	"Research Director",
 	"Scientist",
-	"Geneticist",	//Part of both medical and science
 	"Roboticist",
 	"Xenobiologist",
 	"Lab Assistant"
diff --git a/code/modules/mob/living/simple_animal/hostile/hostile.dm b/code/modules/mob/living/simple_animal/hostile/hostile.dm
index 21bce1f0d1b..bc75fdc929b 100644
--- a/code/modules/mob/living/simple_animal/hostile/hostile.dm
+++ b/code/modules/mob/living/simple_animal/hostile/hostile.dm
@@ -33,7 +33,7 @@
 		return null
 
 	var/atom/T = null
-	var/lowest_health = 100
+	var/lowest_health = INFINITY // Max you can get
 	stop_automated_movement = 0
 
 	for(var/atom/A in targets)
@@ -192,6 +192,8 @@ mob/living/simple_animal/hostile/hitby(atom/movable/AM as mob|obj,var/speed = TH
 		if(HOSTILE_STANCE_IDLE)
 			targets = ListTargets(10)
 			target_mob = FindTarget()
+			if(destroy_surroundings && isnull(target_mob))
+				DestroySurroundings()
 
 		if(HOSTILE_STANCE_ATTACK)
 			if(destroy_surroundings)
diff --git a/code/modules/power/smes.dm b/code/modules/power/smes.dm
index f1d3fd386b2..d565ec72e94 100644
--- a/code/modules/power/smes.dm
+++ b/code/modules/power/smes.dm
@@ -333,7 +333,10 @@
 	// this is the data which will be sent to the ui
 	var/data[0]
 	data["nameTag"] = name_tag
-	data["storedCapacity"] = round(100.0*charge/capacity, 0.1)
+	if(capacity)
+		data["storedCapacity"] = round(100.0*charge/capacity, 0.1)
+	else
+		data["storedCapacity"] = 0
 	data["charging"] = inputting
 	data["chargeMode"] = input_attempt
 	data["chargeLevel"] = input_level
diff --git a/code/modules/recycling/disposal.dm b/code/modules/recycling/disposal.dm
index 13a42ccca75..e7d1b095e57 100644
--- a/code/modules/recycling/disposal.dm
+++ b/code/modules/recycling/disposal.dm
@@ -1412,9 +1412,13 @@
 	var/turf/target	// this will be where the output objects are 'thrown' to.
 	var/mode = 0
 
+	var/spread = 0
+	var/spread_point = 10
+
+
 /obj/structure/disposaloutlet/Initialize()
 	. = ..()
-	target = get_ranged_target_turf(src, dir, 10)
+	target = get_ranged_target_turf(src, dir, spread_point)
 
 	var/obj/structure/disposalpipe/trunk/trunk = locate() in src.loc
 	if(trunk)
@@ -1437,7 +1441,12 @@
 			AM.pipe_eject(dir)
 			if(!istype(AM,/mob/living/silicon/robot/drone)) //Drones keep smashing windows from being fired out of chutes. Bad for the station. ~Z
 				spawn(5)
-					AM.throw_at(target, 3, 1)
+					if(spread)
+						var/turf/new_turf_target = get_step(target,turn(src.dir, rand(-spread,spread)))
+						AM.throw_at(new_turf_target, 3, 1)
+					else
+						AM.throw_at(target, 3, 1)
+
 		H.vent_gas(src.loc)
 		qdel(H)
 
diff --git a/code/modules/research/designs/circuit_designs.dm b/code/modules/research/designs/circuit_designs.dm
index 0a76c264fe4..b898445ba99 100644
--- a/code/modules/research/designs/circuit_designs.dm
+++ b/code/modules/research/designs/circuit_designs.dm
@@ -79,12 +79,6 @@
 	build_path = /obj/item/weapon/circuitboard/pandemic
 	sort_string = "FAEAA"
 
-/datum/design/circuit/scan_console
-	name = "DNA machine"
-	id = "scan_console"
-	build_path = /obj/item/weapon/circuitboard/scan_consolenew
-	sort_string = "FAGAA"
-
 /datum/design/circuit/clonecontrol
 	name = "cloning control console"
 	id = "clonecontrol"
diff --git a/html/changelog.html b/html/changelog.html
index 8c4868a4f59..fe3aabae566 100644
--- a/html/changelog.html
+++ b/html/changelog.html
@@ -56,6 +56,13 @@
 		-->
 		<div class="commit sansserif">
 
+			<h2 class="date">03 June 2018</h2>
+			<h3 class="author">BurgerBB updated:</h3>
+			<ul class="changes bgimages16">
+				<li class="bugfix">Added vents to the cargo warehouse connector to prevent underpressure from disposal inlets.</li>
+				<li class="bugfix">Disposal outlets now spread out items so all the trash doesn't pile up on one tile.</li>
+			</ul>
+
 			<h2 class="date">29 May 2018</h2>
 			<h3 class="author">Kaedwuff updated:</h3>
 			<ul class="changes bgimages16">
diff --git a/html/changelogs/.all_changelog.yml b/html/changelogs/.all_changelog.yml
index 26008dbe624..7e46944753a 100644
--- a/html/changelogs/.all_changelog.yml
+++ b/html/changelogs/.all_changelog.yml
@@ -5523,3 +5523,9 @@ DO NOT EDIT THIS FILE BY HAND!  AUTOMATICALLY GENERATED BY ss13_genchangelog.py.
 2018-05-29:
   Kaedwuff:
   - bugfix: You can no longer slice fruit (or anything else) with a syringe.
+2018-06-03:
+  BurgerBB:
+  - bugfix: Added vents to the cargo warehouse connector to prevent underpressure
+      from disposal inlets.
+  - bugfix: Disposal outlets now spread out items so all the trash doesn't pile up
+      on one tile.
diff --git a/maps/aurora/aurora-4_mainlevel.dmm b/maps/aurora/aurora-4_mainlevel.dmm
index bd0d67ddcbd..08cd2efd739 100644
--- a/maps/aurora/aurora-4_mainlevel.dmm
+++ b/maps/aurora/aurora-4_mainlevel.dmm
@@ -2223,6 +2223,14 @@
 	},
 /turf/simulated/floor/tiled,
 /area/security/brig)
+"aet" = (
+/obj/machinery/vending/hydroseeds{
+	prices = list();
+	restock_items = 1
+	},
+/obj/effect/floor_decal/industrial/outline/yellow,
+/turf/simulated/floor/tiled,
+/area/hydroponics)
 "aeu" = (
 /obj/machinery/atmospherics/pipe/manifold/hidden/supply{
 	dir = 4
@@ -2311,6 +2319,27 @@
 	dir = 4
 	},
 /area/security/brig)
+"aeD" = (
+/obj/item/weapon/material/hatchet,
+/obj/item/weapon/material/minihoe,
+/obj/effect/floor_decal/corner/green{
+	icon_state = "corner_white";
+	dir = 9
+	},
+/obj/structure/table/standard,
+/obj/structure/disposalpipe/segment{
+	dir = 1;
+	icon_state = "pipe-c"
+	},
+/obj/machinery/newscaster{
+	pixel_x = -32
+	},
+/obj/item/watertank,
+/obj/item/weapon/screwdriver,
+/obj/item/weapon/wrench,
+/obj/item/weapon/shovel/spade,
+/turf/simulated/floor/tiled,
+/area/hydroponics)
 "aeE" = (
 /obj/structure/cable/green{
 	d1 = 1;
@@ -2580,6 +2609,11 @@
 	},
 /turf/simulated/floor/tiled,
 /area/security/brig)
+"afd" = (
+/obj/effect/floor_decal/industrial/outline/yellow,
+/obj/machinery/vending/hydronutrients,
+/turf/simulated/floor/tiled,
+/area/hydroponics)
 "afe" = (
 /turf/simulated/wall/r_wall,
 /area/security/investigations)
@@ -2726,6 +2760,11 @@
 	},
 /turf/simulated/floor/tiled,
 /area/security/brig)
+"afy" = (
+/obj/effect/floor_decal/industrial/outline/yellow,
+/obj/machinery/seed_extractor,
+/turf/simulated/floor/tiled,
+/area/hydroponics)
 "afC" = (
 /obj/structure/closet{
 	name = "Evidence Closet"
@@ -7116,41 +7155,6 @@
 /obj/machinery/shield_gen/external,
 /turf/simulated/floor/plating,
 /area/engineering/storage)
-"apt" = (
-/obj/structure/table/rack,
-/obj/item/clothing/suit/space/void/atmos,
-/obj/item/clothing/head/helmet/space/void/atmos,
-/obj/item/clothing/shoes/magboots,
-/obj/item/clothing/mask/breath,
-/obj/structure/window/reinforced{
-	icon_state = "rwindow";
-	dir = 1
-	},
-/obj/effect/floor_decal/industrial/outline/yellow,
-/obj/machinery/door/window/southleft{
-	dir = 4;
-	icon_state = "left";
-	name = "Atmospheric Hardsuits";
-	req_access = list(24)
-	},
-/obj/structure/table/rack,
-/obj/item/clothing/suit/space/void/atmos,
-/obj/item/clothing/head/helmet/space/void/atmos,
-/obj/item/clothing/shoes/magboots,
-/obj/item/clothing/mask/breath,
-/obj/structure/window/reinforced{
-	icon_state = "rwindow";
-	dir = 1
-	},
-/obj/effect/floor_decal/industrial/outline/yellow,
-/obj/machinery/door/window/southleft{
-	dir = 4;
-	icon_state = "left";
-	name = "Atmospheric Hardsuits";
-	req_access = list(24)
-	},
-/turf/simulated/floor/tiled,
-/area/engineering/atmos/storage)
 "apu" = (
 /obj/machinery/atmospherics/unary/vent_scrubber/on{
 	dir = 4
@@ -7719,33 +7723,6 @@
 /obj/machinery/portable_atmospherics/canister/nitrogen,
 /turf/simulated/floor/plating,
 /area/engineering/storage)
-"aqH" = (
-/obj/structure/table/rack,
-/obj/item/clothing/suit/space/void/atmos,
-/obj/item/clothing/head/helmet/space/void/atmos,
-/obj/item/clothing/shoes/magboots,
-/obj/item/clothing/mask/breath,
-/obj/effect/floor_decal/industrial/outline/yellow,
-/obj/machinery/door/window/southleft{
-	dir = 4;
-	icon_state = "left";
-	name = "Atmospheric Hardsuits";
-	req_access = list(24)
-	},
-/obj/structure/table/rack,
-/obj/item/clothing/suit/space/void/atmos,
-/obj/item/clothing/head/helmet/space/void/atmos,
-/obj/item/clothing/shoes/magboots,
-/obj/item/clothing/mask/breath,
-/obj/effect/floor_decal/industrial/outline/yellow,
-/obj/machinery/door/window/southleft{
-	dir = 4;
-	icon_state = "left";
-	name = "Atmospheric Hardsuits";
-	req_access = list(24)
-	},
-/turf/simulated/floor/tiled,
-/area/engineering/atmos/storage)
 "aqI" = (
 /obj/machinery/light,
 /obj/machinery/atmospherics/pipe/simple/hidden/red,
@@ -32678,23 +32655,6 @@
 /obj/item/weapon/circuitboard/arcade/orion_trail,
 /turf/simulated/floor/plating,
 /area/storage/tech)
-"bgk" = (
-/obj/structure/table/rack{
-	dir = 8;
-	layer = 2.9
-	},
-/obj/item/weapon/circuitboard/cloning{
-	pixel_x = 0
-	},
-/obj/item/weapon/circuitboard/clonescanner,
-/obj/item/weapon/circuitboard/clonepod,
-/obj/item/weapon/circuitboard/scan_consolenew,
-/obj/item/weapon/circuitboard/med_data{
-	pixel_x = 3;
-	pixel_y = -3
-	},
-/turf/simulated/floor/plating,
-/area/storage/tech)
 "bgl" = (
 /obj/structure/table/rack{
 	dir = 8;
@@ -57389,18 +57349,6 @@
 /obj/item/weapon/wrapping_paper,
 /turf/simulated/floor/tiled,
 /area/quartermaster/office)
-"cad" = (
-/obj/effect/floor_decal/corner/brown{
-	icon_state = "corner_white";
-	dir = 5
-	},
-/obj/effect/floor_decal/industrial/loading{
-	icon_state = "loadingarea";
-	dir = 1
-	},
-/obj/effect/floor_decal/industrial/outline/yellow,
-/turf/simulated/floor/tiled,
-/area/quartermaster/office)
 "cae" = (
 /obj/effect/floor_decal/corner/brown/full{
 	icon_state = "corner_white_full";
@@ -57714,17 +57662,6 @@
 /obj/effect/large_stock_marker,
 /turf/simulated/floor/tiled,
 /area/quartermaster/office)
-"caM" = (
-/obj/machinery/camera/network/supply{
-	c_tag = "Cargo - Warehouse Entrence";
-	dir = 1
-	},
-/obj/effect/floor_decal/corner/brown{
-	dir = 10
-	},
-/obj/machinery/light/small,
-/turf/simulated/floor/tiled,
-/area/quartermaster/storage)
 "caN" = (
 /obj/effect/floor_decal/corner/brown/full{
 	icon_state = "corner_white_full";
@@ -58283,17 +58220,6 @@
 	},
 /turf/simulated/floor/tiled,
 /area/maintenance/disposal)
-"ccd" = (
-/obj/structure/lattice/catwalk,
-/turf/simulated/open,
-/area/maintenance/disposal)
-"cce" = (
-/obj/structure/lattice/catwalk,
-/obj/structure/sign/drop{
-	pixel_y = 32
-	},
-/turf/simulated/open,
-/area/maintenance/disposal)
 "ccf" = (
 /turf/simulated/open,
 /area/maintenance/disposal)
@@ -58490,15 +58416,6 @@
 	},
 /turf/simulated/floor/tiled,
 /area/maintenance/disposal)
-"ccA" = (
-/obj/structure/disposalpipe/trunk{
-	dir = 4
-	},
-/obj/structure/disposaloutlet{
-	dir = 8
-	},
-/turf/simulated/floor/plating,
-/area/maintenance/disposal)
 "ccB" = (
 /obj/structure/cable{
 	d1 = 1;
@@ -58725,11 +58642,6 @@
 	},
 /turf/simulated/floor/tiled,
 /area/maintenance/disposal)
-"ccW" = (
-/obj/machinery/light/small/emergency,
-/obj/structure/lattice/catwalk,
-/turf/simulated/open,
-/area/maintenance/disposal)
 "ccX" = (
 /obj/machinery/light/small/emergency,
 /obj/structure/closet/crate,
@@ -58801,15 +58713,6 @@
 	},
 /turf/simulated/wall/r_wall,
 /area/maintenance/disposal)
-"cdi" = (
-/obj/structure/disposaloutlet,
-/obj/structure/disposalpipe/trunk{
-	dir = 8
-	},
-/turf/simulated/floor/tiled/airless{
-	icon_state = "asteroidfloor"
-	},
-/area/maintenance/disposal)
 "cdj" = (
 /obj/machinery/light/small/emergency{
 	dir = 8
@@ -64577,21 +64480,40 @@
 /turf/simulated/floor,
 /area/security/security_office)
 "csM" = (
+/obj/structure/table/rack,
+/obj/item/clothing/suit/space/void/atmos,
+/obj/item/clothing/head/helmet/space/void/atmos,
+/obj/item/clothing/shoes/magboots,
+/obj/item/clothing/mask/breath,
+/obj/structure/window/reinforced{
+	icon_state = "rwindow";
+	dir = 1
+	},
+/obj/effect/floor_decal/industrial/outline/yellow,
+/obj/machinery/door/window/southleft{
+	dir = 4;
+	icon_state = "left";
+	name = "Atmospheric Hardsuits";
+	req_access = list(24)
+	},
+/turf/simulated/floor/tiled,
+/area/engineering/atmos/storage)
+"csN" = (
 /turf/simulated/wall,
 /area/security/security_office)
-"csN" = (
+"csO" = (
 /obj/machinery/vending/coffee,
 /obj/effect/floor_decal/industrial/hatch/yellow,
 /turf/simulated/floor/tiled,
 /area/security/security_office)
-"csO" = (
-/turf/simulated/floor/tiled,
-/area/security/security_office)
 "csP" = (
-/obj/machinery/light,
 /turf/simulated/floor/tiled,
 /area/security/security_office)
 "csQ" = (
+/obj/machinery/light,
+/turf/simulated/floor/tiled,
+/area/security/security_office)
+"csR" = (
 /obj/machinery/requests_console{
 	department = "Security";
 	departmentType = 5;
@@ -64599,7 +64521,7 @@
 	},
 /turf/simulated/floor/tiled,
 /area/security/security_office)
-"csR" = (
+"csS" = (
 /obj/machinery/camera/network/security{
 	c_tag = "Security - Security Office";
 	dir = 1;
@@ -64620,7 +64542,7 @@
 	},
 /turf/simulated/floor/tiled,
 /area/security/security_office)
-"csS" = (
+"csT" = (
 /obj/effect/floor_decal/corner/blue{
 	icon_state = "corner_white";
 	dir = 10
@@ -64637,7 +64559,7 @@
 	},
 /turf/simulated/floor/tiled,
 /area/security/security_office)
-"csT" = (
+"csU" = (
 /obj/machinery/hologram/holopad,
 /obj/effect/floor_decal/corner/blue{
 	icon_state = "corner_white";
@@ -64655,7 +64577,7 @@
 	},
 /turf/simulated/floor/tiled,
 /area/security/security_office)
-"csU" = (
+"csV" = (
 /obj/structure/flora/pottedplant/random,
 /obj/effect/floor_decal/corner/blue{
 	icon_state = "corner_white";
@@ -64666,7 +64588,7 @@
 	},
 /turf/simulated/floor/tiled,
 /area/security/security_office)
-"csV" = (
+"csW" = (
 /obj/structure/grille,
 /obj/structure/window/reinforced,
 /obj/structure/window/reinforced{
@@ -64679,7 +64601,7 @@
 /obj/machinery/door/firedoor,
 /turf/simulated/floor,
 /area/security/security_office)
-"csW" = (
+"csX" = (
 /obj/effect/floor_decal/corner/blue,
 /obj/machinery/atmospherics/pipe/simple/hidden/scrubbers,
 /obj/machinery/atmospherics/pipe/manifold/hidden/supply{
@@ -64696,24 +64618,39 @@
 	},
 /turf/simulated/floor/tiled,
 /area/security/brig)
-"csX" = (
-/turf/simulated/wall,
-/area/security/security_office)
 "csY" = (
-/turf/simulated/wall,
-/area/security/security_office)
+/obj/item/clothing/suit/space/void/atmos,
+/obj/item/clothing/head/helmet/space/void/atmos,
+/obj/item/clothing/shoes/magboots,
+/obj/effect/floor_decal/industrial/outline/yellow,
+/obj/machinery/door/window/southleft{
+	dir = 4;
+	icon_state = "left";
+	name = "Atmospheric Hardsuits";
+	req_access = list(24)
+	},
+/obj/structure/table/rack,
+/obj/item/clothing/mask/breath,
+/turf/simulated/floor/tiled,
+/area/engineering/atmos/storage)
 "csZ" = (
-/obj/structure/grille,
-/obj/structure/window/reinforced,
-/obj/structure/window/reinforced{
-	dir = 1
-	},
-/obj/structure/window/reinforced{
-	dir = 8
-	},
-/turf/simulated/floor/plating,
+/turf/simulated/wall,
 /area/security/security_office)
 "cta" = (
+/turf/simulated/wall,
+/area/security/security_office)
+"ctb" = (
+/obj/structure/grille,
+/obj/structure/window/reinforced,
+/obj/structure/window/reinforced{
+	dir = 1
+	},
+/obj/structure/window/reinforced{
+	dir = 8
+	},
+/turf/simulated/floor/plating,
+/area/security/security_office)
+"ctc" = (
 /obj/structure/grille,
 /obj/structure/window/reinforced,
 /obj/structure/window/reinforced{
@@ -64725,43 +64662,11 @@
 	},
 /turf/simulated/floor/plating,
 /area/security/security_office)
-"ctb" = (
-/turf/simulated/wall,
-/area/security/security_office)
-"ctc" = (
-/turf/simulated/wall,
-/area/security/security_office)
 "ctd" = (
-/obj/structure/grille,
-/obj/structure/window/reinforced,
-/obj/structure/window/reinforced{
-	dir = 1
-	},
-/obj/structure/window/reinforced{
-	dir = 4
-	},
-/obj/structure/window/reinforced{
-	icon_state = "rwindow";
-	dir = 8
-	},
-/obj/machinery/door/firedoor,
-/turf/simulated/floor,
+/turf/simulated/wall,
 /area/security/security_office)
 "cte" = (
-/obj/machinery/door/airlock/glass_security{
-	name = "Security Office";
-	req_access = list(63)
-	},
-/obj/structure/cable/green{
-	d1 = 1;
-	d2 = 2;
-	icon_state = "1-2"
-	},
-/obj/machinery/atmospherics/pipe/simple/hidden/supply,
-/obj/structure/disposalpipe/segment,
-/obj/machinery/door/firedoor,
-/obj/machinery/atmospherics/pipe/simple/hidden,
-/turf/simulated/floor/tiled,
+/turf/simulated/wall,
 /area/security/security_office)
 "ctf" = (
 /obj/structure/grille,
@@ -64780,47 +64685,128 @@
 /turf/simulated/floor,
 /area/security/security_office)
 "ctg" = (
-/turf/simulated/wall,
+/obj/machinery/door/airlock/glass_security{
+	name = "Security Office";
+	req_access = list(63)
+	},
+/obj/structure/cable/green{
+	d1 = 1;
+	d2 = 2;
+	icon_state = "1-2"
+	},
+/obj/machinery/atmospherics/pipe/simple/hidden/supply,
+/obj/structure/disposalpipe/segment,
+/obj/machinery/door/firedoor,
+/obj/machinery/atmospherics/pipe/simple/hidden,
+/turf/simulated/floor/tiled,
 /area/security/security_office)
 "cth" = (
-/obj/item/weapon/material/hatchet,
-/obj/item/weapon/material/minihoe,
-/obj/effect/floor_decal/corner/green{
-	icon_state = "corner_white";
-	dir = 9
+/obj/structure/grille,
+/obj/structure/window/reinforced,
+/obj/structure/window/reinforced{
+	dir = 1
 	},
-/obj/structure/table/standard,
-/obj/structure/disposalpipe/segment{
-	dir = 1;
-	icon_state = "pipe-c"
+/obj/structure/window/reinforced{
+	dir = 4
 	},
-/obj/machinery/newscaster{
-	pixel_x = -32
+/obj/structure/window/reinforced{
+	icon_state = "rwindow";
+	dir = 8
 	},
-/obj/item/watertank,
-/obj/item/weapon/screwdriver,
-/obj/item/weapon/wrench,
-/obj/item/weapon/shovel/spade,
-/turf/simulated/floor/tiled,
-/area/hydroponics)
+/obj/machinery/door/firedoor,
+/turf/simulated/floor,
+/area/security/security_office)
 "cti" = (
-/obj/machinery/vending/hydroseeds{
-	prices = list();
-	restock_items = 1
+/turf/simulated/wall,
+/area/security/security_office)
+"ctj" = (
+/obj/structure/table/rack{
+	dir = 8;
+	layer = 2.9
+	},
+/obj/item/weapon/circuitboard/cloning{
+	pixel_x = 0
+	},
+/obj/item/weapon/circuitboard/clonescanner,
+/obj/item/weapon/circuitboard/clonepod,
+/obj/item/weapon/circuitboard/med_data{
+	pixel_x = 3;
+	pixel_y = -3
+	},
+/turf/simulated/floor/plating,
+/area/storage/tech)
+"ctk" = (
+/obj/effect/floor_decal/corner/brown{
+	icon_state = "corner_white";
+	dir = 5
+	},
+/obj/effect/floor_decal/industrial/loading{
+	icon_state = "loadingarea";
+	dir = 1
 	},
 /obj/effect/floor_decal/industrial/outline/yellow,
+/obj/machinery/atmospherics/unary/vent_pump/on,
 /turf/simulated/floor/tiled,
-/area/hydroponics)
-"ctj" = (
-/obj/effect/floor_decal/industrial/outline/yellow,
-/obj/machinery/vending/hydronutrients,
+/area/quartermaster/office)
+"ctl" = (
+/obj/structure/cable/green{
+	d1 = 4;
+	d2 = 8;
+	icon_state = "4-8"
+	},
+/obj/machinery/atmospherics/pipe/manifold/hidden/supply{
+	dir = 1
+	},
+/obj/machinery/atmospherics/pipe/manifold/hidden/scrubbers,
 /turf/simulated/floor/tiled,
-/area/hydroponics)
-"ctk" = (
-/obj/effect/floor_decal/industrial/outline/yellow,
-/obj/machinery/seed_extractor,
+/area/quartermaster/office)
+"ctm" = (
+/obj/machinery/camera/network/supply{
+	c_tag = "Cargo - Warehouse Entrence";
+	dir = 1
+	},
+/obj/effect/floor_decal/corner/brown{
+	dir = 10
+	},
+/obj/machinery/light/small,
+/obj/machinery/atmospherics/unary/vent_scrubber/on{
+	dir = 1
+	},
 /turf/simulated/floor/tiled,
-/area/hydroponics)
+/area/quartermaster/storage)
+"ctn" = (
+/obj/structure/sign/drop{
+	pixel_y = 32
+	},
+/turf/simulated/open,
+/area/maintenance/disposal)
+"cto" = (
+/obj/structure/disposalpipe/trunk{
+	dir = 4
+	},
+/obj/structure/disposaloutlet{
+	dir = 8;
+	spread = 360;
+	spread_point = 2
+	},
+/turf/simulated/floor/plating,
+/area/maintenance/disposal)
+"ctp" = (
+/obj/machinery/light/small/emergency,
+/turf/simulated/open,
+/area/maintenance/disposal)
+"ctq" = (
+/obj/structure/disposaloutlet{
+	spread = 180;
+	spread_point = 1
+	},
+/obj/structure/disposalpipe/trunk{
+	dir = 8
+	},
+/turf/simulated/floor/tiled/airless{
+	icon_state = "asteroidfloor"
+	},
+/area/maintenance/disposal)
 
 (1,1,1) = {"
 aaa
@@ -84198,8 +84184,8 @@ ali
 amf
 anh
 aoh
-apt
-aqH
+csM
+csY
 arV
 atB
 avi
@@ -84226,7 +84212,7 @@ baH
 bcg
 bdD
 beP
-bgk
+ctj
 bhD
 bcc
 bki
@@ -89407,7 +89393,7 @@ bdJ
 bRL
 col
 coy
-cth
+aeD
 coW
 cpi
 cpr
@@ -89424,9 +89410,9 @@ bWF
 bWm
 cih
 cim
-cad
-bXT
-caM
+ctk
+ctl
+ctm
 bWm
 cbs
 cbM
@@ -91209,7 +91195,7 @@ coF
 bSL
 cpc
 bSL
-cti
+aet
 cpI
 bSQ
 cqe
@@ -91723,8 +91709,8 @@ coH
 adu
 adz
 bSL
-ctj
-ctk
+afd
+afy
 bSQ
 cqg
 bRL
@@ -94569,9 +94555,9 @@ bUz
 bPO
 bPK
 cbD
-ccd
 ccf
-ccd
+ccf
+ccf
 cdh
 aaa
 aab
@@ -94826,9 +94812,9 @@ bUz
 caW
 bPL
 cbE
-cce
+ctn
 ccf
-ccW
+ctp
 cdh
 aab
 aab
@@ -95341,7 +95327,7 @@ bPO
 bPL
 cbE
 cbE
-ccA
+cto
 cbE
 cdh
 cdt
@@ -95600,7 +95586,7 @@ cbF
 ccg
 cbD
 cbE
-cdi
+ctq
 cdu
 cdE
 aab
@@ -96531,11 +96517,11 @@ aja
 aja
 crQ
 crZ
-crQ
-csr
-csr
-csr
-csr
+csi
+css
+csC
+csN
+csZ
 asw
 auk
 avI
@@ -96791,8 +96777,8 @@ csa
 csj
 cst
 csD
-csN
-csr
+csO
+cta
 asx
 auk
 avJ
@@ -97045,11 +97031,11 @@ cmy
 crO
 crS
 csb
-crU
-crU
-crU
-crU
-csZ
+csk
+csu
+csE
+csP
+ctb
 asy
 aul
 avK
@@ -97305,8 +97291,8 @@ csc
 csl
 csv
 csF
-csP
-cta
+csQ
+ctc
 asz
 alz
 avL
@@ -97562,8 +97548,8 @@ csd
 csm
 csw
 csG
-csQ
-csr
+csR
+ctd
 asA
 aum
 avK
@@ -97819,8 +97805,8 @@ cse
 csn
 csx
 csH
-csR
-csr
+csS
+cte
 asB
 aun
 avM
@@ -98076,8 +98062,8 @@ csf
 cso
 csy
 csI
-csS
-crQ
+csT
+ctf
 asC
 auo
 avN
@@ -98331,10 +98317,10 @@ cmI
 crX
 csg
 csp
-csp
-csp
-csT
-cte
+csz
+csJ
+csU
+ctg
 cnQ
 aun
 avM
@@ -98577,12 +98563,12 @@ aaV
 adY
 clC
 aja
-crf
+crg
 crm
 cru
 crC
 cmD
-crC
+crN
 cmD
 aja
 crY
@@ -98590,8 +98576,8 @@ csh
 csq
 csA
 csK
-csU
-crQ
+csV
+cth
 asE
 aup
 avK
@@ -98845,10 +98831,10 @@ afe
 afe
 afe
 csr
-csr
+csB
 csL
-csV
-csr
+csW
+cti
 asF
 aun
 avM
@@ -99618,7 +99604,7 @@ alI
 amH
 anD
 aoQ
-csW
+csX
 cnP
 asH
 auq
diff --git a/tools/hooks/README.md b/tools/hooks/README.md
new file mode 100644
index 00000000000..844f3a3952f
--- /dev/null
+++ b/tools/hooks/README.md
@@ -0,0 +1,36 @@
+# Git Integration Hooks
+
+This folder contains installable scripts for [Git hooks] and [merge drivers].
+Use of these hooks and drivers is optional and they must be installed
+explicitly before they take effect.
+
+To install the current set of hooks, or update if new hooks are added, run
+`install.bat` (Windows) or `install.sh` (Unix-like) as appropriate.
+
+Hooks expect a Unix-like environment on the backend. Usually this is handled
+automatically by GUI tools like TortoiseGit and GitHub for Windows, but
+[Git for Windows] is an option if you prefer to use a CLI even on Windows.
+
+## Current Hooks
+
+* **Pre-commit**: Runs [mapmerge2] on changed maps, if any.
+
+## Adding New Hooks
+
+New [Git hooks] may be added by creating a file named `<hook-name>.hook` in
+this directory. Git determines what hooks are available and what their names
+are. The install script copies the `.hook` file into `.git/hooks`, so editing
+the `.hook` file will require a reinstall.
+
+New [merge drivers] may be added by adding a shell script named `<ext>.merge`
+and updating `.gitattributes` in the root of the repository to include the line
+`*.<ext> merge=<ext>`. The install script will set up the merge driver to point
+to the `.merge` file directly, and editing it will not require a reinstall.
+
+`tools/hooks/python.sh` may be used as a trampoline to ensure that the correct
+version of Python is found.
+
+[Git hooks]: https://git-scm.com/book/en/v2/Customizing-Git-Git-Hooks
+[merge drivers]: https://git-scm.com/docs/gitattributes#_performing_a_three_way_merge
+[Git for Windows]: https://gitforwindows.org/
+[mapmerge2]: ../mapmerge2/README.md
diff --git a/tools/hooks/install.bat b/tools/hooks/install.bat
new file mode 100644
index 00000000000..c4f864b5c68
--- /dev/null
+++ b/tools/hooks/install.bat
@@ -0,0 +1,14 @@
+@echo off
+cd %~dp0
+for %%f in (*.hook) do (
+	echo Installing hook: %%~nf
+	copy %%f ..\..\.git\hooks\%%~nf >nul
+)
+for %%f in (*.merge) do (
+	echo Installing merge driver: %%~nf
+	echo [merge "%%~nf"]^
+
+	driver = tools/hooks/%%f %%P %%O %%A %%B %%L >> ..\..\.git\config
+)
+echo Done
+pause
diff --git a/tools/hooks/install.sh b/tools/hooks/install.sh
new file mode 100644
index 00000000000..32183a7ce89
--- /dev/null
+++ b/tools/hooks/install.sh
@@ -0,0 +1,12 @@
+#!/bin/bash
+shopt -s nullglob
+cd "$(dirname "$0")"
+for f in *.hook; do
+	echo Installing hook: ${f%.hook}
+	cp $f ../../.git/hooks/${f%.hook}
+done
+for f in *.merge; do
+	echo Installing merge driver: ${f%.merge}
+	git config --replace-all merge.${f%.merge}.driver "tools/hooks/$f %P %O %A %B %L"
+done
+echo "Done"
diff --git a/tools/hooks/pre-commit.hook b/tools/hooks/pre-commit.hook
new file mode 100644
index 00000000000..7eccda6f58d
--- /dev/null
+++ b/tools/hooks/pre-commit.hook
@@ -0,0 +1,2 @@
+#!/bin/bash
+exec tools/hooks/python.sh -m precommit
diff --git a/tools/hooks/python.sh b/tools/hooks/python.sh
new file mode 100644
index 00000000000..32557070f48
--- /dev/null
+++ b/tools/hooks/python.sh
@@ -0,0 +1,17 @@
+#!/bin/bash
+set -e
+if command -v python3 >/dev/null 2>&1; then
+	PY=python3
+else
+	PY=python
+fi
+PATHSEP=$($PY - <<'EOF'
+import sys, os
+if sys.version_info.major != 3 or sys.version_info.minor < 6:
+	sys.stderr.write("Python 3.6+ is required: " + sys.version + "\n")
+	exit(1)
+print(os.pathsep)
+EOF
+)
+export PYTHONPATH=tools/mapmerge2/${PATHSEP}${PYTHONPATH}
+$PY "$@"
diff --git a/tools/mapmerge2/Prepare Maps - Aurora.bat b/tools/mapmerge2/Prepare Maps - Aurora.bat
new file mode 100644
index 00000000000..5cc98794819
--- /dev/null
+++ b/tools/mapmerge2/Prepare Maps - Aurora.bat	
@@ -0,0 +1,12 @@
+@echo off
+cd ../../maps/aurora
+
+for /R %%f in (*.dmm) do copy "%%f" "%%f.backup"
+
+cls
+echo All dmm files in the maps/aurora directory have been backed up.
+echo Now you can make your changes...
+echo ---
+echo Remember to run mapmerge.bat just before you commit your changes!
+echo ---
+pause
diff --git a/tools/mapmerge2/Prepare Maps - Exodus.bat b/tools/mapmerge2/Prepare Maps - Exodus.bat
new file mode 100644
index 00000000000..bc3e0179f87
--- /dev/null
+++ b/tools/mapmerge2/Prepare Maps - Exodus.bat	
@@ -0,0 +1,12 @@
+@echo off
+cd ../../maps/exodus
+
+for /R %%f in (*.dmm) do copy "%%f" "%%f.backup"
+
+cls
+echo All dmm files in the maps/exodus directory have been backed up.
+echo Now you can make your changes...
+echo ---
+echo Remember to run mapmerge.bat just before you commit your changes!
+echo ---
+pause
diff --git a/tools/mapmerge2/Prepare Maps - Runtime.bat b/tools/mapmerge2/Prepare Maps - Runtime.bat
new file mode 100644
index 00000000000..2c3e15a68d4
--- /dev/null
+++ b/tools/mapmerge2/Prepare Maps - Runtime.bat	
@@ -0,0 +1,12 @@
+@echo off
+cd ../../maps/runtime
+
+for /R %%f in (*.dmm) do copy "%%f" "%%f.backup"
+
+cls
+echo All dmm files in the maps/runtime directory have been backed up.
+echo Now you can make your changes...
+echo ---
+echo Remember to run mapmerge.bat just before you commit your changes!
+echo ---
+pause
diff --git a/tools/mapmerge2/README.md b/tools/mapmerge2/README.md
new file mode 100644
index 00000000000..0ff4d21ac2e
--- /dev/null
+++ b/tools/mapmerge2/README.md
@@ -0,0 +1,52 @@
+# Map Merge 2
+
+**Map Merge 2** is an improvement over previous map merging scripts, with
+better merge-conflict prevention, multi-Z support, and automatic handling of
+key overflow. For up-to-date tips and tricks, also visit the [Map Merger] wiki article.
+
+## What Map Merging Is
+
+The "map merge" operation describes the process of rewriting a map file written
+by the DreamMaker map editor to A) use a format more amenable to Git's conflict
+resolution and B) differ in the least amount textually from the previous
+version of the map while maintaining all the actual changes. It requires an old
+version of the map to use as a reference and a new version of the map which
+contains the desired changes.
+
+## Installation
+
+To install Python dependencies, run `requirements-install.bat`, or run
+`python -m pip install -r requirements.txt` directly. See the [Git hooks]
+documentation to install the Git pre-commit hook which runs the map merger
+automatically, or use `tools/mapmerge/Prepare Maps.bat` to save backups before
+running `mapmerge.bat`.
+
+For up-to-date installation and detailed troubleshooting instructions, visit
+the [Map Merger] wiki article.
+
+## Code Structure
+
+Frontend scripts are meant to be run directly. They obey the environment
+variables `TGM` to set whether files are saved in TGM (1) or DMM (0) format,
+and `MAPROOT` to determine where maps are kept. By default, TGM is used and
+the map root is autodetected. Each script may either prompt for the desired map
+or be run with command-line parameters indicating which maps to act on. The
+scripts include:
+
+* `convert.py` for converting maps to and from the TGM format. Used by
+  `tgm2dmm.bat` and `dmm2tgm.bat`.
+* `mapmerge.py` for running the map merge on map backups saved by
+  `Prepare Maps.bat`. Used by `mapmerge.bat`
+
+Implementation modules:
+
+* `dmm.py` includes the map reader and writer.
+* `mapmerge.py` includes the implementation of the map merge operation.
+* `frontend.py` includes the common code for the frontend scripts.
+
+`precommit.py` is run by the [Git hooks] if installed, and merges the new
+version of any map saved in the index (`git add`ed) with the old version stored
+in Git when run.
+
+[Map Merger]: https://tgstation13.org/wiki/Map_Merger
+[Git hooks]: ../hooks/README.md
diff --git a/tools/mapmerge2/convert.py b/tools/mapmerge2/convert.py
new file mode 100644
index 00000000000..35e5dda4433
--- /dev/null
+++ b/tools/mapmerge2/convert.py
@@ -0,0 +1,8 @@
+#!/usr/bin/env python3
+import frontend
+import dmm
+
+if __name__ == '__main__':
+    settings = frontend.read_settings()
+    for fname in frontend.process(settings, "convert"):
+        dmm.DMM.from_file(fname).to_file(fname, settings.tgm)
diff --git a/tools/mapmerge2/dmm.py b/tools/mapmerge2/dmm.py
new file mode 100644
index 00000000000..d76f07e32c6
--- /dev/null
+++ b/tools/mapmerge2/dmm.py
@@ -0,0 +1,488 @@
+# Tools for working with DreamMaker maps
+
+import io
+import bidict
+import random
+from collections import namedtuple
+
+TGM_HEADER = "//MAP CONVERTED BY dmm2tgm.py THIS HEADER COMMENT PREVENTS RECONVERSION, DO NOT REMOVE"
+ENCODING = 'utf-8'
+
+Coordinate = namedtuple('Coordinate', ['x', 'y', 'z'])
+
+class DMM:
+    __slots__ = ['key_length', 'size', 'dictionary', 'grid', 'header']
+
+    def __init__(self, key_length, size):
+        self.key_length = key_length
+        self.size = size
+        self.dictionary = bidict.bidict()
+        self.grid = {}
+        self.header = None
+
+    @staticmethod
+    def from_file(fname):
+        # stream the file rather than forcing all its contents to memory
+        with open(fname, 'r', encoding=ENCODING) as f:
+            return _parse(iter(lambda: f.read(1), ''))
+
+    @staticmethod
+    def from_bytes(bytes):
+        return _parse(bytes.decode(ENCODING))
+
+    def to_file(self, fname, tgm = True):
+        self._presave_checks()
+        with open(fname, 'w', newline='\n', encoding=ENCODING) as f:
+            (save_tgm if tgm else save_dmm)(self, f)
+
+    def to_bytes(self, tgm = True):
+        self._presave_checks()
+        bio = io.BytesIO()
+        with io.TextIOWrapper(bio, newline='\n', encoding=ENCODING) as f:
+            (save_tgm if tgm else save_dmm)(self, f)
+            f.flush()
+            return bio.getvalue()
+
+    def generate_new_key(self):
+        free_keys = self._ensure_free_keys(1)
+        # choose one of the free keys at random
+        key = 0
+        while free_keys:
+            if key not in self.dictionary:
+                # this construction is used to avoid needing to construct the
+                # full set in order to random.choice() from it
+                if random.random() < 1 / free_keys:
+                    return key
+                free_keys -= 1
+            key += 1
+
+        raise RuntimeError("ran out of keys, this shouldn't happen")
+
+    def _presave_checks(self):
+        # last-second handling of bogus keys to help prevent and fix broken maps
+        self._ensure_free_keys(0)
+        max_key = max_key_for(self.key_length)
+        bad_keys = {key: 0 for key in self.dictionary.keys() if key > max_key}
+        if bad_keys:
+            print(f"Warning: fixing {len(bad_keys)} overflowing keys")
+            for k in bad_keys:
+                # create a new non-bogus key and transfer that value to it
+                new_key = bad_keys[k] = self.generate_new_key()
+                self.dictionary.forceput(new_key, self.dictionary[k])
+                print(f"    {num_to_key(k, self.key_length, True)} -> {num_to_key(new_key, self.key_length)}")
+            for k, v in self.grid.items():
+                # reassign the grid entries which used the old key
+                self.grid[k] = bad_keys.get(v, v)
+
+    def _ensure_free_keys(self, desired):
+        # ensure that free keys exist by increasing the key length if necessary
+        free_keys = max_key_for(self.key_length) - len(self.dictionary)
+        while free_keys < desired:
+            if self.key_length >= MAX_KEY_LENGTH:
+                raise KeyTooLarge(f"can't expand beyond key length {MAX_KEY_LENGTH} ({len(self.dictionary)} keys)")
+            self.key_length += 1
+            free_keys = max_key_for(self.key_length) - len(self.dictionary)
+        return free_keys
+
+    @property
+    def coords_zyx(self):
+        for z in range(1, self.size.z + 1):
+            for y in range(1, self.size.y + 1):
+                for x in range(1, self.size.x + 1):
+                    yield (z, y, x)
+
+    @property
+    def coords_z(self):
+        return range(1, self.size.z + 1)
+
+    @property
+    def coords_yx(self):
+        for y in range(1, self.size.y + 1):
+            for x in range(1, self.size.x + 1):
+                yield (y, x)
+
+# ----------
+# key handling
+
+# Base 52 a-z A-Z dictionary for fast conversion
+MAX_KEY_LENGTH = 3  # things will get ugly fast if you exceed this
+BASE = 52
+base52 = 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ'
+base52_r = {x: i for i, x in enumerate(base52)}
+assert len(base52) == BASE and len(base52_r) == BASE
+
+def key_to_num(key):
+    num = 0
+    for ch in key:
+        num = BASE * num + base52_r[ch]
+    return num
+
+def num_to_key(num, key_length, allow_overflow=False):
+    if num >= (BASE ** key_length if allow_overflow else max_key_for(key_length)):
+        raise KeyTooLarge(f"num={num} does not fit in key_length={key_length}")
+
+    result = ''
+    while num:
+        result = base52[num % BASE] + result
+        num //= BASE
+
+    assert len(result) <= key_length
+    return base52[0] * (key_length - len(result)) + result
+
+def max_key_for(key_length):
+    # keys only go up to "ymo" = 65534, under-estimated just in case
+    # https://secure.byond.com/forum/?post=2340796#comment23770802
+    return min(65530, BASE ** key_length)
+
+class KeyTooLarge(Exception):
+    pass
+
+# ----------
+# An actual atom parser
+
+def parse_map_atom(atom):
+    try:
+        i = atom.index('{')
+    except ValueError:
+        return atom, {}
+
+    path, rest = atom[:i], atom[i+1:]
+    vars = {}
+
+    in_string = False
+    in_name = False
+    escaping = False
+    current_name = ''
+    current = ''
+    for ch in rest:
+        if escaping:
+            escaping = False
+            current += ch
+        elif ch == '\\':
+            escaping = True
+        elif ch == '"':
+            in_string = not in_string
+            current += ch
+        elif in_string:
+            current += ch
+        elif ch == ';':
+            vars[current_name.strip()] = current.strip()
+            current_name = current = ''
+        elif ch == '=':
+            current_name = current
+            current = ''
+        elif ch == '}':
+            vars[current_name.strip()] = current.strip()
+            break
+        elif ch not in ' ':
+            current += ch
+
+    return path, vars
+
+# ----------
+# TGM writer
+
+def save_tgm(dmm, output):
+    output.write(f"{TGM_HEADER}\n")
+    if dmm.header:
+        output.write(f"{dmm.header}\n")
+
+    # write dictionary in tgm format
+    for key, value in sorted(dmm.dictionary.items()):
+        output.write(f'"{num_to_key(key, dmm.key_length)}" = (\n')
+        for idx, thing in enumerate(value):
+            in_quote_block = False
+            in_varedit_block = False
+            for char in thing:
+                if in_quote_block:
+                    if char == '"':
+                        in_quote_block = False
+                    output.write(char)
+                elif char == '"':
+                    in_quote_block = True
+                    output.write(char)
+                elif not in_varedit_block:
+                    if char == "{":
+                        in_varedit_block = True
+                        output.write("{\n\t")
+                    else:
+                        output.write(char)
+                elif char == ";":
+                    output.write(";\n\t")
+                elif char == "}":
+                    output.write("\n\t}")
+                    in_varedit_block = False
+                else:
+                    output.write(char)
+            if idx < len(value) - 1:
+                output.write(",\n")
+        output.write(")\n")
+
+    # thanks to YotaXP for finding out about this one
+    max_x, max_y, max_z = dmm.size
+    for z in range(1, max_z + 1):
+        output.write("\n")
+        for x in range(1, max_x + 1):
+            output.write(f"({x},{1},{z}) = {{\"\n")
+            for y in range(1, max_y + 1):
+                output.write(f"{num_to_key(dmm.grid[x, y, z], dmm.key_length)}\n")
+            output.write("\"}\n")
+
+# ----------
+# DMM writer
+
+def save_dmm(dmm, output):
+    if dmm.header:
+        output.write(f"{dmm.header}\n")
+
+    # writes a tile dictionary the same way Dreammaker does
+    for key, value in sorted(dmm.dictionary.items()):
+        output.write(f'"{num_to_key(key, dmm.key_length)}" = ({",".join(value)})\n')
+
+    output.write("\n")
+
+    # writes a map grid the same way Dreammaker does
+    max_x, max_y, max_z = dmm.size
+    for z in range(1, max_z + 1):
+        output.write(f"(1,1,{z}) = {{\"\n")
+
+        for y in range(1, max_y + 1):
+            for x in range(1, max_x + 1):
+                try:
+                    output.write(num_to_key(dmm.grid[x, y, z], dmm.key_length))
+                except KeyError:
+                    print(f"Key error: ({x}, {y}, {z})")
+            output.write("\n")
+        output.write("\"}\n")
+
+# ----------
+# Parser
+
+def _parse(map_raw_text):
+    in_comment_line = False
+    comment_trigger = False
+
+    in_quote_block = False
+    in_key_block = False
+    in_data_block = False
+    in_varedit_block = False
+    after_data_block = False
+    escaping = False
+    skip_whitespace = False
+
+    dictionary = bidict.bidict()
+    duplicate_keys = {}
+    curr_key_len = 0
+    curr_key = 0
+    curr_datum = ""
+    curr_data = list()
+
+    in_map_block = False
+    in_coord_block = False
+    in_map_string = False
+    iter_x = 0
+    adjust_y = True
+
+    curr_num = ""
+    reading_coord = "x"
+
+    key_length = 0
+
+    maxx = 0
+    maxy = 0
+    maxz = 0
+
+    curr_x = 0
+    curr_y = 0
+    curr_z = 0
+    grid = dict()
+
+    it = iter(map_raw_text)
+
+    # map block
+    for char in it:
+        if char == "\n":
+            in_comment_line = False
+            comment_trigger = False
+            continue
+        elif in_comment_line:
+            continue
+        elif char == "\t":
+            continue
+
+        if char == "/" and not in_quote_block:
+            if comment_trigger:
+                in_comment_line = True
+                continue
+            else:
+                comment_trigger = True
+        else:
+            comment_trigger = False
+
+        if in_data_block:
+
+            if in_varedit_block:
+
+                if in_quote_block:
+                    if char == "\\":
+                        curr_datum = curr_datum + char
+                        escaping = True
+
+                    elif escaping:
+                        curr_datum = curr_datum + char
+                        escaping = False
+
+                    elif char == "\"":
+                        curr_datum = curr_datum + char
+                        in_quote_block = False
+
+                    else:
+                        curr_datum = curr_datum + char
+
+                else:
+                    if skip_whitespace and char == " ":
+                        skip_whitespace = False
+                        continue
+                    skip_whitespace = False
+
+                    if char == "\"":
+                        curr_datum = curr_datum + char
+                        in_quote_block = True
+
+                    elif char == ";":
+                        skip_whitespace = True
+                        curr_datum = curr_datum + char
+
+                    elif char == "}":
+                        curr_datum = curr_datum + char
+                        in_varedit_block = False
+
+                    else:
+                        curr_datum = curr_datum + char
+
+            elif char == "{":
+                curr_datum = curr_datum + char
+                in_varedit_block = True
+
+            elif char == ",":
+                curr_data.append(curr_datum)
+                curr_datum = ""
+
+            elif char == ")":
+                curr_data.append(curr_datum)
+                curr_data = tuple(curr_data)
+                try:
+                    dictionary[curr_key] = curr_data
+                except bidict.ValueDuplicationError:
+                    # if the map has duplicate values, eliminate them now
+                    duplicate_keys[curr_key] = dictionary.inv[curr_data]
+                curr_data = list()
+                curr_datum = ""
+                curr_key = 0
+                curr_key_len = 0
+                in_data_block = False
+                after_data_block = True
+
+            else:
+                curr_datum = curr_datum + char
+
+        elif in_key_block:
+            if char == "\"":
+                in_key_block = False
+                if key_length == 0:
+                    key_length = curr_key_len
+                else:
+                    assert key_length == curr_key_len
+            else:
+                curr_key = BASE * curr_key + base52_r[char]
+                curr_key_len += 1
+
+        # else we're looking for a key block, a data block or the map block
+        elif char == "\"":
+            in_key_block = True
+            after_data_block = False
+
+        elif char == "(":
+            if after_data_block:
+                in_coord_block = True
+                after_data_block = False
+                curr_key = 0
+                curr_key_len = 0
+                break
+            else:
+                in_data_block = True
+                after_data_block = False
+
+    # grid block
+    for char in it:
+        if in_coord_block:
+            if char == ",":
+                if reading_coord == "x":
+                    curr_x = int(curr_num)
+                    if curr_x > maxx:
+                        maxx = curr_x
+                    iter_x = 0
+                    curr_num = ""
+                    reading_coord = "y"
+                elif reading_coord == "y":
+                    curr_y = int(curr_num)
+                    if curr_y > maxy:
+                        maxy = curr_y
+                    curr_num = ""
+                    reading_coord = "z"
+                else:
+                    raise ValueError("too many dimensions")
+
+            elif char == ")":
+                curr_z = int(curr_num)
+                if curr_z > maxz:
+                    maxz = curr_z
+                in_coord_block = False
+                reading_coord = "x"
+                curr_num = ""
+
+            else:
+                curr_num = curr_num + char
+
+        elif in_map_string:
+            if char == "\"":
+                in_map_string = False
+                adjust_y = True
+                curr_y -= 1
+
+            elif char == "\n":
+                if adjust_y:
+                    adjust_y = False
+                else:
+                    curr_y += 1
+                if curr_x > maxx:
+                    maxx = curr_x
+                if iter_x > 1:
+                    curr_x = 1
+                iter_x = 0
+
+            else:
+                curr_key = BASE * curr_key + base52_r[char]
+                curr_key_len += 1
+                if curr_key_len == key_length:
+                    iter_x += 1
+                    if iter_x > 1:
+                        curr_x += 1
+
+                    grid[curr_x, curr_y, curr_z] = duplicate_keys.get(curr_key, curr_key)
+                    curr_key = 0
+                    curr_key_len = 0
+
+        # else look for coordinate block or a map string
+        elif char == "(":
+            in_coord_block = True
+        elif char == "\"":
+            in_map_string = True
+
+    if curr_y > maxy:
+        maxy = curr_y
+
+    data = DMM(key_length, Coordinate(maxx, maxy, maxz))
+    data.dictionary = dictionary
+    data.grid = grid
+    return data
diff --git a/tools/mapmerge2/dmm2tgm.bat b/tools/mapmerge2/dmm2tgm.bat
new file mode 100644
index 00000000000..b17b03afa08
--- /dev/null
+++ b/tools/mapmerge2/dmm2tgm.bat
@@ -0,0 +1,5 @@
+@echo off
+set MAPROOT=../../maps/
+set TGM=1
+python convert.py
+pause
diff --git a/tools/mapmerge2/frontend.py b/tools/mapmerge2/frontend.py
new file mode 100644
index 00000000000..4d44eab951e
--- /dev/null
+++ b/tools/mapmerge2/frontend.py
@@ -0,0 +1,127 @@
+# Common code for the frontend interface of map tools
+import sys
+import os
+import pathlib
+import shutil
+from collections import namedtuple
+
+Settings = namedtuple('Settings', ['map_folder', 'tgm'])
+MapsToRun = namedtuple('MapsToRun', ['files', 'indices'])
+
+def string_to_num(s):
+    try:
+        return int(s)
+    except ValueError:
+        return -1
+
+def read_settings():
+    # discover map folder if needed
+    try:
+        map_folder = os.environ['MAPROOT']
+    except KeyError:
+        map_folder = '_maps/'
+        for _ in range(8):
+            if os.path.exists(map_folder):
+                break
+            map_folder = os.path.join('..', map_folder)
+        else:
+            map_folder = None
+
+    # assume TGM is True by default
+    tgm = os.environ.get('TGM', "1") == "1"
+
+    return Settings(map_folder, tgm)
+
+def pretty_path(settings, path_str):
+    if settings.map_folder:
+        return path_str[len(os.path.commonpath([settings.map_folder, path_str]))+1:]
+    else:
+        return path_str
+
+def prompt_maps(settings, verb):
+    if not settings.map_folder:
+        print("Could not autodetect the _maps folder, set MAPROOT")
+        exit(1)
+
+    list_of_files = list()
+    for root, directories, filenames in os.walk(settings.map_folder):
+        for filename in [f for f in filenames if f.endswith(".dmm")]:
+            list_of_files.append(pathlib.Path(root, filename))
+
+    last_dir = ""
+    for i, this_file in enumerate(list_of_files):
+        this_dir = this_file.parent
+        if last_dir != this_dir:
+            print("--------------------------------")
+            last_dir = this_dir
+        print("[{}]: {}".format(i, pretty_path(settings, str(this_file))))
+
+    print("--------------------------------")
+    in_list = input("List the maps you want to " + verb + " (example: 1,3-5,12):\n")
+    in_list = in_list.replace(" ", "")
+    in_list = in_list.split(",")
+
+    valid_indices = list()
+    for m in in_list:
+        index_range = m.split("-")
+        if len(index_range) == 1:
+            index = string_to_num(index_range[0])
+            if index >= 0 and index < len(list_of_files):
+                valid_indices.append(index)
+        elif len(index_range) == 2:
+            index0 = string_to_num(index_range[0])
+            index1 = string_to_num(index_range[1])
+            if index0 >= 0 and index0 <= index1 and index1 < len(list_of_files):
+                valid_indices.extend(range(index0, index1 + 1))
+
+    return MapsToRun(list_of_files, valid_indices)
+
+def process(settings, verb, *, modify=True, backup=None):
+    if backup is None:
+        backup = modify  # by default, backup when we modify
+    assert modify or not backup  # doesn't make sense to backup when not modifying
+
+    if len(sys.argv) > 1:
+        maps = sys.argv[1:]
+    else:
+        maps = prompt_maps(settings, verb)
+        maps = [str(maps.files[i]) for i in maps.indices]
+        print()
+
+    if not maps:
+        print("No maps selected.")
+        return
+
+    if modify:
+        print(f"Maps WILL{'' if settings.tgm else ' NOT'} be converted to tgm.")
+        if backup:
+            print("Backups will be created with a \".before\" extension.")
+        else:
+            print("Warning: backups are NOT being taken.")
+
+    print(f"\nWill {verb} these maps:")
+    for path_str in maps:
+        print(pretty_path(settings, path_str))
+
+    try:
+        confirm = input(f"\nPress Enter to {verb}...\n")
+    except KeyboardInterrupt:
+        confirm = "^C"
+    if confirm != "":
+        print(f"\nAborted.")
+        return
+
+    for path_str in maps:
+        print(f' - {pretty_path(settings, path_str)}')
+
+        if backup:
+            shutil.copyfile(path_str, path_str + ".before")
+
+        try:
+            yield path_str
+        except Exception as e:
+            print(f"Error: {e}")
+        else:
+            print("Succeeded.")
+
+    print("\nFinished.")
diff --git a/tools/mapmerge2/mapmerge.bat b/tools/mapmerge2/mapmerge.bat
new file mode 100644
index 00000000000..e12c500bc83
--- /dev/null
+++ b/tools/mapmerge2/mapmerge.bat
@@ -0,0 +1,5 @@
+@echo off
+set MAPROOT=../../maps/
+set TGM=1
+python mapmerge.py
+pause
diff --git a/tools/mapmerge2/mapmerge.py b/tools/mapmerge2/mapmerge.py
new file mode 100644
index 00000000000..f449bd948f0
--- /dev/null
+++ b/tools/mapmerge2/mapmerge.py
@@ -0,0 +1,94 @@
+#!/usr/bin/env python3
+import frontend
+import shutil
+from dmm import *
+from collections import defaultdict
+
+def merge_map(new_map, old_map, delete_unused=False):
+    if new_map.key_length != old_map.key_length:
+        print("Warning: Key lengths differ, taking new map")
+        print(f"  Old: {old_map.key_length}")
+        print(f"  New: {new_map.key_length}")
+        return new_map
+
+    if new_map.size != old_map.size:
+        print("Warning: Map dimensions differ, taking new map")
+        print(f"  Old: {old_map.size}")
+        print(f"  New: {new_map.size}")
+        return new_map
+
+    key_length, size = old_map.key_length, old_map.size
+    merged = DMM(key_length, size)
+    merged.dictionary = old_map.dictionary.copy()
+
+    known_keys = dict()  # mapping fron 'new' key to 'merged' key
+    unused_keys = set(old_map.dictionary.keys())  # keys going unused
+
+    # step one: parse the new version, compare it to the old version, merge both
+    for z, y, x in new_map.coords_zyx:
+        new_key = new_map.grid[x, y, z]
+        # if this key has been processed before, it can immediately be merged
+        try:
+            merged.grid[x, y, z] = known_keys[new_key]
+            continue
+        except KeyError:
+            pass
+
+        def select_key(assigned):
+            merged.grid[x, y, z] = known_keys[new_key] = assigned
+
+        old_key = old_map.grid[x, y, z]
+        old_tile = old_map.dictionary[old_key]
+        new_tile = new_map.dictionary[new_key]
+
+        # this tile is the exact same as before, so the old key is used
+        if new_tile == old_tile:
+            select_key(old_key)
+            unused_keys.remove(old_key)
+
+        # the tile is different here, but if it exists in the merged dictionary, that key can be used
+        elif new_tile in merged.dictionary.inv:
+            newold_key = merged.dictionary.inv[new_tile]
+            select_key(newold_key)
+            unused_keys.remove(newold_key)
+
+        # the tile is brand new and it needs a new key, but if the old key isn't being used any longer it can be used instead
+        elif old_tile not in new_map.dictionary.inv and old_key in unused_keys:
+            merged.dictionary[old_key] = new_tile
+            select_key(old_key)
+            unused_keys.remove(old_key)
+
+        # all other options ruled out, a brand new key is generated for the brand new tile
+        else:
+            fresh_key = merged.generate_new_key()
+            merged.dictionary[fresh_key] = new_tile
+            select_key(fresh_key)
+
+    # step two: delete unused keys
+    if unused_keys:
+        print(f"Notice: Trimming {len(unused_keys)} unused dictionary keys.")
+        for key in unused_keys:
+            del merged.dictionary[key]
+
+    # sanity check: that the merged map equals the new map
+    for z, y, x in new_map.coords_zyx:
+        new_tile = new_map.dictionary[new_map.grid[x, y, z]]
+        merged_tile = merged.dictionary[merged.grid[x, y, z]]
+        if new_tile != merged_tile:
+            print(f"Error: the map has been mangled! This is a mapmerge bug!")
+            print(f"At {x},{y},{z}.")
+            print(f"Should be {new_tile}")
+            print(f"Instead is {merged_tile}")
+            raise RuntimeError()
+
+    return merged
+
+def main(settings):
+    for fname in frontend.process(settings, "merge", backup=True):
+        shutil.copyfile(fname, fname + ".before")
+        old_map = DMM.from_file(fname + ".backup")
+        new_map = DMM.from_file(fname)
+        merge_map(new_map, old_map).to_file(fname, settings.tgm)
+
+if __name__ == '__main__':
+    main(frontend.read_settings())
diff --git a/tools/mapmerge2/precommit.py b/tools/mapmerge2/precommit.py
new file mode 100644
index 00000000000..381f1ea8a3e
--- /dev/null
+++ b/tools/mapmerge2/precommit.py
@@ -0,0 +1,50 @@
+#!/usr/bin/env python3
+import os
+import pygit2
+import dmm
+from mapmerge import merge_map
+
+def main(repo):
+    if repo.index.conflicts:
+        print("You need to resolve merge conflicts first.")
+        return 1
+
+    changed = 0
+    for path, status in repo.status().items():
+        if path.endswith(".dmm") and (status & (pygit2.GIT_STATUS_INDEX_MODIFIED | pygit2.GIT_STATUS_INDEX_NEW)):
+            # read the index
+            index_entry = repo.index[path]
+            index_map = dmm.DMM.from_bytes(repo[index_entry.id].read_raw())
+
+            try:
+                head_blob = repo[repo[repo.head.target].tree[path].id]
+            except KeyError:
+                # New map, no entry in HEAD
+                print(f"Converting new map: {path}")
+                assert (status & pygit2.GIT_STATUS_INDEX_NEW)
+                merged_map = index_map
+            else:
+                # Entry in HEAD, merge the index over it
+                print(f"Merging map: {path}")
+                assert not (status & pygit2.GIT_STATUS_INDEX_NEW)
+                head_map = dmm.DMM.from_bytes(head_blob.read_raw())
+                merged_map = merge_map(index_map, head_map)
+
+            # write to the index
+            blob_id = repo.create_blob(merged_map.to_bytes())
+            repo.index.add(pygit2.IndexEntry(path, blob_id, index_entry.mode))
+            changed += 1
+
+            # write to the working directory if that's clean
+            if status & (pygit2.GIT_STATUS_WT_DELETED | pygit2.GIT_STATUS_WT_MODIFIED):
+                print(f"Warning: {path} has unindexed changes, not overwriting them")
+            else:
+                merged_map.to_file(os.path.join(repo.workdir, path))
+
+    if changed:
+        repo.index.write()
+        print(f"Merged {changed} maps.")
+    return 0
+
+if __name__ == '__main__':
+    exit(main(pygit2.Repository(pygit2.discover_repository(os.getcwd()))))
diff --git a/tools/mapmerge2/requirements-install.bat b/tools/mapmerge2/requirements-install.bat
new file mode 100644
index 00000000000..71341af8792
--- /dev/null
+++ b/tools/mapmerge2/requirements-install.bat
@@ -0,0 +1,3 @@
+@echo off
+python -m pip install -r requirements.txt
+pause
diff --git a/tools/mapmerge2/requirements.txt b/tools/mapmerge2/requirements.txt
new file mode 100644
index 00000000000..d01a2c6ccff
--- /dev/null
+++ b/tools/mapmerge2/requirements.txt
@@ -0,0 +1,2 @@
+pygit2==0.26.0
+bidict==0.13.1
diff --git a/tools/mapmerge2/tgm2dmm.bat b/tools/mapmerge2/tgm2dmm.bat
new file mode 100644
index 00000000000..5bf5677453c
--- /dev/null
+++ b/tools/mapmerge2/tgm2dmm.bat
@@ -0,0 +1,5 @@
+@echo off
+set MAPROOT=../../maps/
+set TGM=0
+python convert.py
+pause