diff --git a/code/__DEFINES/dcs/signals/signals_atom/signals_atom_explosion.dm b/code/__DEFINES/dcs/signals/signals_atom/signals_atom_explosion.dm
index d2328f5e500..7d7ba861398 100644
--- a/code/__DEFINES/dcs/signals/signals_atom/signals_atom_explosion.dm
+++ b/code/__DEFINES/dcs/signals/signals_atom/signals_atom_explosion.dm
@@ -11,3 +11,5 @@
 	/// When returned on a signal hooked to [COMSIG_ATOM_EXPLODE], [COMSIG_ATOM_INTERNAL_EXPLOSION], or [COMSIG_AREA_INTERNAL_EXPLOSION] it prevents the explosion from being propagated further.
 	#define COMSIG_CANCEL_EXPLOSION (1<<0)
 
+/// from [/atom/movable/proc/set_explosion_resistance] : (old_block, new_block)
+#define COMSIG_MOVABLE_EXPLOSION_BLOCK_CHANGED "explosion_block_changed"
diff --git a/code/__DEFINES/explosions.dm b/code/__DEFINES/explosions.dm
index cd30f89f1b0..f867ee9b813 100644
--- a/code/__DEFINES/explosions.dm
+++ b/code/__DEFINES/explosions.dm
@@ -18,9 +18,6 @@
 /// Gibtonite will now explode
 #define GIBTONITE_DETONATE 3
 
-/// For object explosion block calculation
-#define EXPLOSION_BLOCK_PROC -1
-
 /// A wrapper for [/atom/proc/ex_act] to ensure that the explosion propagation and attendant signal are always handled.
 #define EX_ACT(target, args...)\
 	if(!(target.flags_1 & PREVENT_CONTENTS_EXPLOSION_1)) { \
diff --git a/code/__DEFINES/is_helpers.dm b/code/__DEFINES/is_helpers.dm
index 0ffa7235fe4..16aaf019de9 100644
--- a/code/__DEFINES/is_helpers.dm
+++ b/code/__DEFINES/is_helpers.dm
@@ -281,3 +281,4 @@ GLOBAL_LIST_INIT(book_types, typecacheof(list(
 #define is_unassigned_job(job_type) (istype(job_type, /datum/job/unassigned))
 
 #define isprojectilespell(thing) (istype(thing, /datum/action/cooldown/spell/pointed/projectile))
+#define is_multi_tile_object(atom) (atom.bound_width > world.icon_size || atom.bound_height > world.icon_size)
diff --git a/code/__DEFINES/maths.dm b/code/__DEFINES/maths.dm
index db411b6285d..7117d7b4645 100644
--- a/code/__DEFINES/maths.dm
+++ b/code/__DEFINES/maths.dm
@@ -237,5 +237,9 @@
 
 #define GET_TRUE_DIST(a, b) (a == null || b == null) ? -1 : max(abs(a.x -b.x), abs(a.y-b.y), abs(a.z-b.z))
 
+//We used to use linear regression to approximate the answer, but Mloc realized this was actually faster.
+//And lo and behold, it is, and it's more accurate to boot.
+#define CHEAP_HYPOTENUSE(Ax, Ay, Bx, By) (sqrt(abs(Ax - Bx) ** 2 + abs(Ay - By) ** 2)) //A squared + B squared = C squared
+
 /// The number of cells in a taxicab circle (rasterized diamond) of radius X.
 #define DIAMOND_AREA(X) (1 + 2*(X)*((X)+1))
diff --git a/code/__DEFINES/traits.dm b/code/__DEFINES/traits.dm
index ae87eabb5fb..846d2b96dec 100644
--- a/code/__DEFINES/traits.dm
+++ b/code/__DEFINES/traits.dm
@@ -517,6 +517,8 @@ Remember to update _globalvars/traits.dm if you're adding/removing/renaming trai
 #define TRAIT_PARALYSIS "paralysis"
 /// Used for limbs.
 #define TRAIT_DISABLED_BY_WOUND "disabled-by-wound"
+/// This movable atom has the explosive block element
+#define TRAIT_BLOCKING_EXPLOSIVES "blocking_explosives"
 
 /// Mobs with this trait can't send the mining shuttle console when used outside the station itself
 #define TRAIT_FORBID_MINING_SHUTTLE_CONSOLE_OUTSIDE_STATION "forbid_mining_shuttle_console_outside_station"
diff --git a/code/__HELPERS/game.dm b/code/__HELPERS/game.dm
index 8cf6be1b04f..ccca11387dd 100644
--- a/code/__HELPERS/game.dm
+++ b/code/__HELPERS/game.dm
@@ -11,12 +11,6 @@
 		return null
 	return format_text ? format_text(checked_area.name) : checked_area.name
 
-//We used to use linear regression to approximate the answer, but Mloc realized this was actually faster.
-//And lo and behold, it is, and it's more accurate to boot.
-///Calculate the hypotenuse cheaply (this should be in maths.dm)
-/proc/cheap_hypotenuse(Ax, Ay, Bx, By)
-	return sqrt(abs(Ax - Bx) ** 2 + abs(Ay - By) ** 2) //A squared + B squared = C squared
-
 /** toggle_organ_decay
  * inputs: first_object (object to start with)
  * outputs:
diff --git a/code/controllers/subsystem/explosions.dm b/code/controllers/subsystem/explosions.dm
index 177beb45cae..a7becb28706 100644
--- a/code/controllers/subsystem/explosions.dm
+++ b/code/controllers/subsystem/explosions.dm
@@ -119,30 +119,31 @@ SUBSYSTEM_DEF(explosions)
 	var/x0 = epicenter.x
 	var/y0 = epicenter.y
 	var/list/wipe_colours = list()
-	for(var/turf/T in spiral_range_turfs(max_range, epicenter))
-		wipe_colours += T
-		var/dist = cheap_hypotenuse(T.x, T.y, x0, y0)
+	var/list/cached_exp_block = list()
+	for(var/turf/explode in prepare_explosion_turfs(max_range, epicenter))
+		wipe_colours += explode
+		var/our_x = explode.x
+		var/our_y = explode.y
+		var/dist = CHEAP_HYPOTENUSE(our_x, our_y, x0, y0)
 
 		if(newmode == "Yes")
-			var/turf/TT = T
-			while(TT != epicenter)
-				TT = get_step_towards(TT,epicenter)
-				if(TT.density)
-					dist += TT.explosion_block
-
-				for(var/obj/O in T)
-					var/the_block = O.explosion_block
-					dist += the_block == EXPLOSION_BLOCK_PROC ? O.GetExplosionBlock() : the_block
+			if(explode != epicenter)
+				var/our_block = cached_exp_block[get_step_towards(explode, epicenter)]
+				dist += our_block
+				cached_exp_block[explode] = our_block + explode.explosive_resistance
+			else
+				cached_exp_block[explode] = explode.explosive_resistance
 
+		dist = round(dist, 0.01)
 		if(dist < dev)
-			T.color = "red"
-			T.maptext = MAPTEXT("Dev")
+			explode.color = "red"
+			explode.maptext = MAPTEXT("[dist]")
 		else if (dist < heavy)
-			T.color = "yellow"
-			T.maptext = MAPTEXT("Heavy")
+			explode.color = "yellow"
+			explode.maptext = MAPTEXT("[dist]")
 		else if (dist < light)
-			T.color = "blue"
-			T.maptext = MAPTEXT("Light")
+			explode.color = "blue"
+			explode.maptext = MAPTEXT("[dist]")
 		else
 			continue
 
@@ -379,82 +380,77 @@ SUBSYSTEM_DEF(explosions)
 		for(var/mob/living/L in viewers(flash_range, epicenter))
 			L.flash_act()
 
-	var/list/affected_turfs = GatherSpiralTurfs(max_range, epicenter)
+	var/list/affected_turfs = prepare_explosion_turfs(max_range, epicenter)
 
 	var/reactionary = CONFIG_GET(flag/reactionary_explosions)
-	var/list/cached_exp_block
-
-	if(reactionary)
-		cached_exp_block = CaculateExplosionBlock(affected_turfs)
+	// this list is setup in the form position -> block for that position
+	// we assert that turfs will be processed closed to farthest, so we can build this as we go along
+	// This is gonna be an array, index'd by turfs
+	var/list/cached_exp_block = list()
 
 	//lists are guaranteed to contain at least 1 turf at this point
+	//we presuppose that we'll be iterating away from the epicenter
+	for(var/turf/explode as anything in affected_turfs)
+		var/our_x = explode.x
+		var/our_y = explode.y
+		var/dist = CHEAP_HYPOTENUSE(our_x, our_y, x0, y0)
 
-	for(var/TI in affected_turfs)
-		var/turf/T = TI
-		var/init_dist = cheap_hypotenuse(T.x, T.y, x0, y0)
-		var/dist = init_dist
-
+		// Using this pattern, block will flow out from blocking turfs, essentially caching the recursion
+		// This is safe because if get_step_towards is ever anything but caridnally off, it'll do a diagonal move
+		// So we always sample from a "loop" closer
+		// It's kind of behaviorly unimpressive that that's a problem for the future
 		if(reactionary)
-			var/turf/Trajectory = T
-			while(Trajectory != epicenter)
-				Trajectory = get_step_towards(Trajectory, epicenter)
-				dist += cached_exp_block[Trajectory]
+			if(explode == epicenter)
+				cached_exp_block[explode] = explode.explosive_resistance
+			else
+				var/our_block = cached_exp_block[get_step_towards(explode, epicenter)]
+				dist += our_block
+				cached_exp_block[explode] = our_block + explode.explosive_resistance
 
-		var/flame_dist = dist < flame_range
-		var/throw_dist = dist
 
+		var/severity = EXPLODE_NONE
 		if(dist < devastation_range)
-			dist = EXPLODE_DEVASTATE
+			severity = EXPLODE_DEVASTATE
 		else if(dist < heavy_impact_range)
-			dist = EXPLODE_HEAVY
+			severity = EXPLODE_HEAVY
 		else if(dist < light_impact_range)
-			dist = EXPLODE_LIGHT
-		else
-			dist = EXPLODE_NONE
+			severity = EXPLODE_LIGHT
 
-		if(T == epicenter) // Ensures explosives detonating from bags trigger other explosives in that bag
+		if(explode == epicenter) // Ensures explosives detonating from bags trigger other explosives in that bag
 			var/list/items = list()
-			for(var/I in T)
-				var/atom/A = I
-				if (length(A.contents) && !(A.flags_1 & PREVENT_CONTENTS_EXPLOSION_1)) //The atom/contents_explosion() proc returns null if the contents ex_acting has been handled by the atom, and TRUE if it hasn't.
-					items += A.get_all_contents(ignore_flag_1 = PREVENT_CONTENTS_EXPLOSION_1)
-				if(isliving(A))
-					items -= A		//Stops mobs from taking double damage from explosions originating from them/their turf, such as from projectiles
-			for(var/thing in items)
-				var/atom/movable/movable_thing = thing
-				if(QDELETED(movable_thing))
-					continue
-				switch(dist)
-					if(EXPLODE_DEVASTATE)
-						SSexplosions.high_mov_atom += movable_thing
-					if(EXPLODE_HEAVY)
-						SSexplosions.med_mov_atom += movable_thing
-					if(EXPLODE_LIGHT)
-						SSexplosions.low_mov_atom += movable_thing
-		switch(dist)
+			for(var/atom/holder as anything in explode)
+				if (length(holder.contents) && !(holder.flags_1 & PREVENT_CONTENTS_EXPLOSION_1)) //The atom/contents_explosion() proc returns null if the contents ex_acting has been handled by the atom, and TRUE if it hasn't.
+					items += holder.get_all_contents(ignore_flag_1 = PREVENT_CONTENTS_EXPLOSION_1)
+				if(isliving(holder))
+					items -= holder		//Stops mobs from taking double damage from explosions originating from them/their turf, such as from projectiles
+			switch(severity)
+				if(EXPLODE_DEVASTATE)
+					SSexplosions.high_mov_atom += items
+				if(EXPLODE_HEAVY)
+					SSexplosions.med_mov_atom += items
+				if(EXPLODE_LIGHT)
+					SSexplosions.low_mov_atom += items
+		switch(severity)
 			if(EXPLODE_DEVASTATE)
-				SSexplosions.highturf += T
+				SSexplosions.highturf += explode
 			if(EXPLODE_HEAVY)
-				SSexplosions.medturf += T
+				SSexplosions.medturf += explode
 			if(EXPLODE_LIGHT)
-				SSexplosions.lowturf += T
+				SSexplosions.lowturf += explode
 
-
-		if(flame_dist && prob(40) && !isspaceturf(T) && !T.density)
-			flameturf += T
+		if(prob(40) && dist < flame_range && !isspaceturf(explode) && !explode.density)
+			flameturf += explode
 
 		//--- THROW ITEMS AROUND ---
-		var/throw_dir = get_dir(epicenter,T)
-		var/throw_range = max_range-throw_dist
-		var/list/throwingturf = T.explosion_throw_details
-		if (throwingturf)
-			if (throwingturf[1] < throw_range)
-				throwingturf[1] = throw_range
-				throwingturf[2] = throw_dir
+		if (explode.explosion_throw_details)
+			var/list/throwingturf = explode.explosion_throw_details
+			if (throwingturf[1] < max_range - dist)
+				throwingturf[1] = max_range - dist
+				throwingturf[2] = get_dir(epicenter, explode)
 				throwingturf[3] = max_range
 		else
-			T.explosion_throw_details = list(throw_range, throw_dir, max_range)
-			throwturf += T
+			explode.explosion_throw_details = list(max_range - dist, get_dir(epicenter, explode), max_range)
+			throwturf += explode
 
 
 	var/took = (REALTIMEOFDAY - started_at) / 10
@@ -572,68 +568,40 @@ SUBSYSTEM_DEF(explosions)
 #undef FREQ_UPPER
 #undef FREQ_LOWER
 
-/datum/controller/subsystem/explosions/proc/GatherSpiralTurfs(range, turf/epicenter)
+/// Returns a list of turfs in X range from the epicenter
+/// Returns in a unique order, spiraling outwards
+/// This is done to ensure our progressive cache of blast resistance is always valid
+/// This is quite fast
+/proc/prepare_explosion_turfs(range, turf/epicenter)
 	var/list/outlist = list()
-	var/center = epicenter
-	var/dist = range
-	if(!dist)
-		outlist += center
-		return outlist
+	// Add in the center
+	outlist += epicenter
 
-	var/turf/t_center = get_turf(center)
-	if(!t_center)
-		return outlist
+	var/our_x = epicenter.x
+	var/our_y = epicenter.y
+	var/our_z = epicenter.z
 
-	var/list/L = outlist
-	var/turf/T
-	var/y
-	var/x
-	var/c_dist = 1
-	L += t_center
+	var/max_x = world.maxx
+	var/max_y = world.maxy
+	for(var/i in 1 to range)
+		var/lowest_x = our_x - i
+		var/lowest_y = our_y - i
+		var/highest_x = our_x + i
+		var/highest_y = our_y + i
+		// top left to one before top right
+		if(highest_y <= max_y)
+			outlist += block(locate(max(lowest_x, 1), highest_y, our_z), locate(min(highest_x - 1, max_x), highest_y, our_z))
+		// top right to one before bottom right
+		if(highest_x <= max_x)
+			outlist += block(locate(highest_x, min(highest_y, max_y), our_z), locate(highest_x, max(lowest_y + 1, 1), our_z))
+		// bottom right to one before bottom left
+		if(lowest_y >= 1)
+			outlist += block(locate(min(highest_x, max_x), lowest_y, our_z), locate(max(lowest_x + 1, 1), lowest_y, our_z))
+		// bottom left to one before top left
+		if(lowest_x >= 1)
+			outlist += block(locate(lowest_x, max(lowest_y, 1), our_z), locate(lowest_x, min(highest_y - 1, max_y), our_z))
 
-	while( c_dist <= dist )
-		y = t_center.y + c_dist
-		x = t_center.x - c_dist + 1
-		for(x in x to t_center.x+c_dist)
-			T = locate(x,y,t_center.z)
-			if(T)
-				L += T
-
-		y = t_center.y + c_dist - 1
-		x = t_center.x + c_dist
-		for(y in t_center.y-c_dist to y)
-			T = locate(x,y,t_center.z)
-			if(T)
-				L += T
-
-		y = t_center.y - c_dist
-		x = t_center.x + c_dist - 1
-		for(x in t_center.x-c_dist to x)
-			T = locate(x,y,t_center.z)
-			if(T)
-				L += T
-
-		y = t_center.y - c_dist + 1
-		x = t_center.x - c_dist
-		for(y in y to t_center.y+c_dist)
-			T = locate(x,y,t_center.z)
-			if(T)
-				L += T
-		c_dist++
-	. = L
-
-/datum/controller/subsystem/explosions/proc/CaculateExplosionBlock(list/affected_turfs)
-	. = list()
-	var/I
-	for(I in 1 to affected_turfs.len) // we cache the explosion block rating of every turf in the explosion area
-		var/turf/T = affected_turfs[I]
-		var/current_exp_block = T.density ? T.explosion_block : 0
-
-		for(var/obj/O in T)
-			var/the_block = O.explosion_block
-			current_exp_block += the_block == EXPLOSION_BLOCK_PROC ? O.GetExplosionBlock() : the_block
-
-		.[T] = current_exp_block
+	return outlist
 
 /datum/controller/subsystem/explosions/fire(resumed = 0)
 	if (!is_exploding())
@@ -722,15 +690,15 @@ SUBSYSTEM_DEF(explosions)
 		for (var/thing in throw_turf)
 			if (!thing)
 				continue
-			var/turf/T = thing
-			var/list/L = T.explosion_throw_details
-			T.explosion_throw_details = null
-			if (length(L) != 3)
+			var/turf/explode = thing
+			var/list/details = explode.explosion_throw_details
+			explode.explosion_throw_details = null
+			if (length(details) != 3)
 				continue
-			var/throw_range = L[1]
-			var/throw_dir = L[2]
-			var/max_range = L[3]
-			for(var/atom/movable/A in T)
+			var/throw_range = details[1]
+			var/throw_dir = details[2]
+			var/max_range = details[3]
+			for(var/atom/movable/A in explode)
 				if(QDELETED(A))
 					continue
 				if(!A.anchored && A.move_resist != INFINITY)
diff --git a/code/datums/elements/blocks_explosives.dm b/code/datums/elements/blocks_explosives.dm
new file mode 100644
index 00000000000..1e867a81c1e
--- /dev/null
+++ b/code/datums/elements/blocks_explosives.dm
@@ -0,0 +1,56 @@
+/// Apply this element to a movable atom when you want it to block explosions
+/// It will mirror the blocking down to that movable's turf, keeping explosion work cheap
+/datum/element/blocks_explosives
+
+/datum/element/blocks_explosives/Attach(datum/target)
+	if(!ismovable(target))
+		return
+	. = ..()
+	ADD_TRAIT(target, TRAIT_BLOCKING_EXPLOSIVES, TRAIT_GENERIC)
+	var/atom/movable/moving_target = target
+	RegisterSignal(moving_target, COMSIG_MOVABLE_MOVED, PROC_REF(blocker_moved))
+	RegisterSignal(moving_target, COMSIG_MOVABLE_EXPLOSION_BLOCK_CHANGED, PROC_REF(blocking_changed))
+	moving_target.explosive_resistance = moving_target.explosion_block
+
+	if(length(moving_target.locs) > 1)
+		for(var/atom/location as anything in moving_target.locs)
+			block_loc(location, moving_target.explosion_block)
+	else if(moving_target.loc)
+		block_loc(moving_target.loc, moving_target.explosion_block)
+
+/datum/element/blocks_explosives/Detach(datum/source)
+	. = ..()
+	REMOVE_TRAIT(source, TRAIT_BLOCKING_EXPLOSIVES, TRAIT_GENERIC)
+
+/// Call this when our blocking well, changes. we'll update our turf(s) with the details
+/datum/element/blocks_explosives/proc/blocking_changed(atom/movable/target, old_block, new_block)
+	if(length(target.locs) > 1)
+		for(var/atom/location as anything in target.locs)
+			unblock_loc(location, old_block)
+			block_loc(location, new_block)
+	else if(target.loc)
+		unblock_loc(target.loc, old_block)
+		block_loc(target.loc, new_block)
+
+/// Applies a block amount to a turf. proc for convenince
+/datum/element/blocks_explosives/proc/block_loc(atom/location, block_amount)
+	location.explosive_resistance += block_amount
+
+/// Removes a block amount from a turf. proc for convenince
+/datum/element/blocks_explosives/proc/unblock_loc(atom/location, block_amount)
+	location.explosive_resistance -= block_amount
+
+/// Essentially just blocking_changed except we remove from the old loc, and add to the new one
+/datum/element/blocks_explosives/proc/blocker_moved(atom/movable/target, atom/old_loc, dir, forced, list/old_locs)
+	if(length(old_locs) > 1)
+		for(var/atom/location as anything in old_locs)
+			unblock_loc(location, target.explosion_block)
+	else if(old_loc)
+		unblock_loc(old_loc, target.explosion_block)
+
+	if(length(target.locs) > 1)
+		for(var/atom/location as anything in target.locs)
+			block_loc(location, target.explosion_block)
+	else if(target.loc)
+		block_loc(target.loc, target.explosion_block)
+
diff --git a/code/game/atoms.dm b/code/game/atoms.dm
index 6b758061a04..696be4274d9 100644
--- a/code/game/atoms.dm
+++ b/code/game/atoms.dm
@@ -39,8 +39,8 @@
 	///HUD images that this atom can provide.
 	var/list/hud_possible
 
-	///Value used to increment ex_act() if reactionary_explosions is on
-	var/explosion_block = 0
+	///How much this atom resists explosions by, in the end
+	var/explosive_resistance = 0
 
 	/**
 	 * used to store the different colors on an atom
@@ -1850,6 +1850,10 @@
 
 	pixel_y = pixel_y + base_pixel_y - .
 
+// Not a valid operation, turfs and movables handle block differently
+/atom/proc/set_explosion_block(explosion_block)
+	return
+
 /**
  * Returns true if this atom has gravity for the passed in turf
  *
diff --git a/code/game/atoms_movable.dm b/code/game/atoms_movable.dm
index 6a97e1c370a..d67695d0093 100644
--- a/code/game/atoms_movable.dm
+++ b/code/game/atoms_movable.dm
@@ -94,6 +94,11 @@
 	/// The degree of pressure protection that mobs in list/contents have from the external environment, between 0 and 1
 	var/contents_pressure_protection = 0
 
+	/// Value used to increment ex_act() if reactionary_explosions is on
+	/// How much we as a source block explosions by
+	/// Will not automatically apply to the turf below you, you need to apply /datum/element/block_explosives in conjunction with this
+	var/explosion_block = 0
+
 /mutable_appearance/emissive_blocker
 
 /mutable_appearance/emissive_blocker/New()
@@ -104,6 +109,11 @@
 
 /atom/movable/Initialize(mapload)
 	. = ..()
+#ifdef UNIT_TESTS
+	if(explosion_block && !HAS_TRAIT(src, TRAIT_BLOCKING_EXPLOSIVES))
+		stack_trace("[type] blocks explosives, but does not have the managing element applied")
+#endif
+
 	switch(blocks_emissive)
 		if(EMISSIVE_BLOCK_GENERIC)
 			var/static/mutable_appearance/emissive_blocker/blocker = new()
@@ -515,7 +525,7 @@
 	if(set_dir_on_move && dir != direction && update_dir)
 		setDir(direction)
 
-	var/is_multi_tile_object = bound_width > 32 || bound_height > 32
+	var/is_multi_tile_object = is_multi_tile_object(src)
 
 	var/list/old_locs
 	if(is_multi_tile_object && isturf(loc))
@@ -1129,6 +1139,13 @@
 
 	return TRUE
 
+/atom/movable/set_explosion_block(explosion_block)
+	var/old_block = src.explosion_block
+	explosive_resistance -= old_block
+	src.explosion_block = explosion_block
+	explosive_resistance += explosion_block
+	SEND_SIGNAL(src, COMSIG_MOVABLE_EXPLOSION_BLOCK_CHANGED, old_block, explosion_block)
+
 /atom/movable/proc/throw_impact(atom/hit_atom, datum/thrownthing/throwingdatum)
 	set waitfor = FALSE
 	var/hitpush = TRUE
diff --git a/code/game/machinery/doors/door.dm b/code/game/machinery/doors/door.dm
index 18d33711fd8..b81d87a6cac 100644
--- a/code/game/machinery/doors/door.dm
+++ b/code/game/machinery/doors/door.dm
@@ -57,6 +57,7 @@
 	acid = 70
 
 /obj/machinery/door/Initialize(mapload)
+	AddElement(/datum/element/blocks_explosives)
 	. = ..()
 	set_init_door_layer()
 	update_freelook_sight()
@@ -72,7 +73,7 @@
 
 	//doors only block while dense though so we have to use the proc
 	real_explosion_block = explosion_block
-	explosion_block = EXPLOSION_BLOCK_PROC
+	update_explosive_block()
 	RegisterSignal(SSsecurity_level, COMSIG_SECURITY_LEVEL_CHANGED, PROC_REF(check_security_level))
 
 	var/static/list/loc_connections = list(
@@ -483,9 +484,6 @@
 	//if it blows up a wall it should blow up a door
 	return ..(severity ? min(EXPLODE_DEVASTATE, severity + 1) : EXPLODE_NONE, target)
 
-/obj/machinery/door/GetExplosionBlock()
-	return density ? real_explosion_block : 0
-
 /obj/machinery/door/power_change()
 	. = ..()
 	if(. && !(machine_stat & NOPOWER))
@@ -501,4 +499,19 @@
 
 	INVOKE_ASYNC(src, PROC_REF(open))
 
+/obj/machinery/door/set_density(new_value)
+	. = ..()
+	update_explosive_block()
+
+/obj/machinery/door/proc/update_explosive_block()
+	set_explosion_block(real_explosion_block)
+
+// Kinda roundabout, essentially if we're dense, we respect real_explosion_block
+// Otherwise, we block nothing
+/obj/machinery/door/set_explosion_block(explosion_block)
+	real_explosion_block = explosion_block
+	if(density)
+		return ..()
+	return ..(0)
+
 #undef DOOR_CLOSE_WAIT
diff --git a/code/game/objects/items/RCD.dm b/code/game/objects/items/RCD.dm
index d5710ba8c3b..bb64fc89072 100644
--- a/code/game/objects/items/RCD.dm
+++ b/code/game/objects/items/RCD.dm
@@ -1008,7 +1008,7 @@ GLOBAL_VAR_INIT(icon_holographic_window, init_holographic_window())
 							if(istype(O))
 								var/x0 = O.x
 								var/y0 = O.y
-								var/contender = cheap_hypotenuse(start.x, start.y, x0, y0)
+								var/contender = CHEAP_HYPOTENUSE(start.x, start.y, x0, y0)
 								if(!winner)
 									winner = O
 									winning_dist = contender
diff --git a/code/game/objects/items/puzzle_pieces.dm b/code/game/objects/items/puzzle_pieces.dm
index 93321819ce4..b176d2b6823 100644
--- a/code/game/objects/items/puzzle_pieces.dm
+++ b/code/game/objects/items/puzzle_pieces.dm
@@ -210,6 +210,7 @@
 	acid = 100
 
 /obj/structure/light_puzzle/Initialize(mapload)
+	AddElement(/datum/element/blocks_explosives)
 	. = ..()
 	var/generated_board = -1
 	while(generated_board in banned_combinations)
diff --git a/code/game/objects/structures/window.dm b/code/game/objects/structures/window.dm
index 61247b7163a..38988209284 100644
--- a/code/game/objects/structures/window.dm
+++ b/code/game/objects/structures/window.dm
@@ -40,6 +40,7 @@
 	acid = 100
 
 /obj/structure/window/Initialize(mapload, direct)
+	AddElement(/datum/element/blocks_explosives)
 	. = ..()
 	if(direct)
 		setDir(direct)
@@ -55,9 +56,9 @@
 		setDir()
 		AddElement(/datum/element/can_barricade)
 
-	//windows only block while reinforced and fulltile, so we'll use the proc
-	real_explosion_block = explosion_block
-	explosion_block = EXPLOSION_BLOCK_PROC
+	//windows only block while reinforced and fulltile
+	if(!reinf || !fulltile)
+		set_explosion_block(0)
 
 	flags_1 |= ALLOW_DARK_PAINTS_1
 	RegisterSignal(src, COMSIG_OBJ_PAINTED, PROC_REF(on_painted))
@@ -424,9 +425,6 @@
 
 	return TRUE
 
-/obj/structure/window/GetExplosionBlock()
-	return reinf && fulltile ? real_explosion_block : 0
-
 /obj/structure/window/spawner/east
 	dir = EAST
 
diff --git a/code/game/turfs/change_turf.dm b/code/game/turfs/change_turf.dm
index 4c7fbda0e4a..0d04fcab2c4 100644
--- a/code/game/turfs/change_turf.dm
+++ b/code/game/turfs/change_turf.dm
@@ -78,6 +78,9 @@ GLOBAL_LIST_INIT(blacklisted_automated_baseturfs, typecacheof(list(
 	var/old_dynamic_lumcount = dynamic_lumcount
 	var/old_rcd_memory = rcd_memory
 	var/old_always_lit = always_lit
+	var/old_explosion_throw_details = explosion_throw_details
+	// We get just the bits of explosive_resistance that aren't the turf
+	var/old_explosive_resistance = explosive_resistance - get_explosive_block()
 	var/old_lattice_underneath = lattice_underneath
 
 	var/old_bp = blueprint_data
@@ -117,6 +120,8 @@ GLOBAL_LIST_INIT(blacklisted_automated_baseturfs, typecacheof(list(
 
 	new_turf.blueprint_data = old_bp
 	new_turf.rcd_memory = old_rcd_memory
+	new_turf.explosion_throw_details = old_explosion_throw_details
+	new_turf.explosive_resistance += old_explosive_resistance
 
 	lighting_corner_NE = old_lighting_corner_NE
 	lighting_corner_SE = old_lighting_corner_SE
diff --git a/code/game/turfs/closed/_closed.dm b/code/game/turfs/closed/_closed.dm
index 58af2771652..10d2a353b2e 100644
--- a/code/game/turfs/closed/_closed.dm
+++ b/code/game/turfs/closed/_closed.dm
@@ -20,7 +20,7 @@
 	name = "wall"
 	desc = "Effectively impervious to conventional methods of destruction."
 	icon = 'icons/turf/walls.dmi'
-	explosion_block = 50
+	explosive_resistance = 50
 
 /turf/closed/indestructible/rust_heretic_act()
 	return
@@ -280,7 +280,7 @@ INITIALIZE_IMMEDIATE(/turf/closed/indestructible/splashscreen)
 	desc = "A seemingly impenetrable wall."
 	icon = 'icons/turf/walls.dmi'
 	icon_state = "necro"
-	explosion_block = 50
+	explosive_resistance = 50
 	baseturfs = /turf/closed/indestructible/necropolis
 
 /turf/closed/indestructible/necropolis/get_smooth_underlay_icon(mutable_appearance/underlay_appearance, turf/asking_turf, adjacency_dir)
@@ -308,7 +308,7 @@ INITIALIZE_IMMEDIATE(/turf/closed/indestructible/splashscreen)
 	smoothing_flags = SMOOTH_BITMASK
 	smoothing_groups = SMOOTH_GROUP_CLOSED_TURFS + SMOOTH_GROUP_BOSS_WALLS
 	canSmoothWith = SMOOTH_GROUP_BOSS_WALLS
-	explosion_block = 50
+	explosive_resistance = 50
 	baseturfs = /turf/closed/indestructible/riveted/boss
 
 /turf/closed/indestructible/riveted/boss/see_through
diff --git a/code/game/turfs/closed/wall/mineral_walls.dm b/code/game/turfs/closed/wall/mineral_walls.dm
index 9bcd1b4061f..6e88d4640a3 100644
--- a/code/game/turfs/closed/wall/mineral_walls.dm
+++ b/code/game/turfs/closed/wall/mineral_walls.dm
@@ -15,7 +15,7 @@
 	base_icon_state = "gold_wall"
 	sheet_type = /obj/item/stack/sheet/mineral/gold
 	hardness = 65 //gold is soft
-	explosion_block = 0 //gold is a soft metal you dingus.
+	explosive_resistance = 0 //gold is a soft metal you dingus.
 	smoothing_groups = SMOOTH_GROUP_GOLD_WALLS + SMOOTH_GROUP_WALLS + SMOOTH_GROUP_CLOSED_TURFS
 	canSmoothWith = SMOOTH_GROUP_GOLD_WALLS
 	custom_materials = list(/datum/material/gold = 4000)
@@ -42,7 +42,7 @@
 	sheet_type = /obj/item/stack/sheet/mineral/diamond
 	hardness = 5 //diamond is very hard
 	slicing_duration = 200   //diamond wall takes twice as much time to slice
-	explosion_block = 3
+	explosive_resistance = 3
 	smoothing_flags = SMOOTH_BITMASK
 	smoothing_groups = SMOOTH_GROUP_DIAMOND_WALLS + SMOOTH_GROUP_WALLS + SMOOTH_GROUP_CLOSED_TURFS
 	canSmoothWith = SMOOTH_GROUP_DIAMOND_WALLS
@@ -72,7 +72,7 @@
 	base_icon_state = "sandstone_wall"
 	sheet_type = /obj/item/stack/sheet/mineral/sandstone
 	hardness = 50 //moh says this is apparently 6-7 on it's scale
-	explosion_block = 0
+	explosive_resistance = 0
 	smoothing_flags = SMOOTH_BITMASK
 	smoothing_groups = SMOOTH_GROUP_SANDSTONE_WALLS + SMOOTH_GROUP_WALLS + SMOOTH_GROUP_CLOSED_TURFS
 	canSmoothWith = SMOOTH_GROUP_SANDSTONE_WALLS
@@ -158,7 +158,7 @@
 	sheet_type = /obj/item/stack/sheet/mineral/wood
 	hardness = 80
 	turf_flags = IS_SOLID
-	explosion_block = 0
+	explosive_resistance = 0
 	smoothing_flags = SMOOTH_BITMASK
 	smoothing_groups = SMOOTH_GROUP_WOOD_WALLS + SMOOTH_GROUP_WALLS + SMOOTH_GROUP_CLOSED_TURFS
 	canSmoothWith = SMOOTH_GROUP_WOOD_WALLS
@@ -215,7 +215,7 @@
 	base_icon_state = "snow_wall"
 	smoothing_flags = SMOOTH_BITMASK
 	hardness = 80
-	explosion_block = 0
+	explosive_resistance = 0
 	slicing_duration = 30
 	sheet_type = /obj/item/stack/sheet/mineral/snow
 	canSmoothWith = null
@@ -236,7 +236,7 @@
 	sheet_type = /obj/item/stack/sheet/mineral/abductor
 	hardness = 10
 	slicing_duration = 200   //alien wall takes twice as much time to slice
-	explosion_block = 3
+	explosive_resistance = 3
 	smoothing_flags = SMOOTH_BITMASK | SMOOTH_DIAGONAL_CORNERS
 	smoothing_groups = SMOOTH_GROUP_ABDUCTOR_WALLS + SMOOTH_GROUP_WALLS + SMOOTH_GROUP_CLOSED_TURFS
 	canSmoothWith = SMOOTH_GROUP_ABDUCTOR_WALLS
@@ -250,7 +250,7 @@
 	icon = 'icons/turf/walls/shuttle_wall.dmi'
 	icon_state = "shuttle_wall-0"
 	base_icon_state = "shuttle_wall"
-	explosion_block = 3
+	explosive_resistance = 3
 	flags_1 = CAN_BE_DIRTY_1
 	flags_ricochet = RICOCHET_SHINY | RICOCHET_HARD
 	sheet_type = /obj/item/stack/sheet/mineral/titanium
@@ -314,7 +314,7 @@
 	icon = 'icons/turf/walls/plastitanium_wall.dmi'
 	icon_state = "plastitanium_wall-0"
 	base_icon_state = "plastitanium_wall"
-	explosion_block = 4
+	explosive_resistance = 4
 	sheet_type = /obj/item/stack/sheet/mineral/plastitanium
 	hardness = 25 //upgrade on titanium
 	smoothing_flags = SMOOTH_BITMASK | SMOOTH_DIAGONAL_CORNERS
diff --git a/code/game/turfs/closed/wall/reinf_walls.dm b/code/game/turfs/closed/wall/reinf_walls.dm
index f41e21be848..d496c7f438b 100644
--- a/code/game/turfs/closed/wall/reinf_walls.dm
+++ b/code/game/turfs/closed/wall/reinf_walls.dm
@@ -12,7 +12,7 @@
 	sheet_type = /obj/item/stack/sheet/plasteel
 	sheet_amount = 1
 	girder_type = /obj/structure/girder/reinforced
-	explosion_block = 2
+	explosive_resistance = 2
 	rad_insulation = RAD_HEAVY_INSULATION
 	heat_capacity = 312500 //a little over 5 cm thick , 312500 for 1 m by 2.5 m by 0.25 m plasteel wall. also indicates the temperature at wich the wall will melt (currently only able to melt with H/E pipes)
 	///Dismantled state, related to deconstruction.
@@ -233,7 +233,7 @@
 	icon = 'icons/turf/walls/plastitanium_wall.dmi'
 	icon_state = "plastitanium_wall-0"
 	base_icon_state = "plastitanium_wall"
-	explosion_block = 20
+	explosive_resistance = 20
 	sheet_type = /obj/item/stack/sheet/mineral/plastitanium
 	hardness = 25 //plastitanium
 	turf_flags = IS_SOLID
diff --git a/code/game/turfs/closed/walls.dm b/code/game/turfs/closed/walls.dm
index 4528c21db05..c9363912add 100644
--- a/code/game/turfs/closed/walls.dm
+++ b/code/game/turfs/closed/walls.dm
@@ -6,7 +6,7 @@
 	icon = 'icons/turf/walls/wall.dmi'
 	icon_state = "wall-0"
 	base_icon_state = "wall"
-	explosion_block = 1
+	explosive_resistance = 1
 
 	thermal_conductivity = WALL_HEAT_TRANSFER_COEFFICIENT
 	heat_capacity = 62500 //a little over 5 cm thick , 62500 for 1 m by 2.5 m by 0.25 m iron wall. also indicates the temperature at wich the wall will melt (currently only able to melt with H/E pipes)
@@ -266,7 +266,7 @@
 	return null
 
 /turf/closed/wall/acid_act(acidpwr, acid_volume)
-	if(explosion_block >= 2)
+	if(get_explosive_block() >= 2)
 		acidpwr = min(acidpwr, 50) //we reduce the power so strong walls never get melted.
 	return ..()
 
diff --git a/code/game/turfs/open/space/transit.dm b/code/game/turfs/open/space/transit.dm
index e0a9981a83d..74ba0e6fb0a 100644
--- a/code/game/turfs/open/space/transit.dm
+++ b/code/game/turfs/open/space/transit.dm
@@ -5,7 +5,7 @@
 	dir = SOUTH
 	baseturfs = /turf/open/space/transit
 	flags_1 = NOJAUNT //This line goes out to every wizard that ever managed to escape the den. I'm sorry.
-	explosion_block = INFINITY
+	explosive_resistance = INFINITY
 
 /turf/open/space/transit/Initialize(mapload)
 	. = ..()
diff --git a/code/game/turfs/turf.dm b/code/game/turfs/turf.dm
index 2da6be00cab..3ecadaed44a 100755
--- a/code/game/turfs/turf.dm
+++ b/code/game/turfs/turf.dm
@@ -92,6 +92,12 @@ GLOBAL_LIST_EMPTY(station_turfs)
 	/// Sorry for the mess
 	var/area/in_contents_of
 #endif
+	/// How much explosive resistance this turf is providing to itself
+	/// Defaults to -1, interpreted as initial(explosive_resistance)
+	/// This is an optimization to prevent turfs from needing to set these on init
+	/// This would either be expensive, or impossible to manage. Let's just avoid it yes?
+	/// Never directly access this, use get_explosive_block() instead
+	var/inherent_explosive_resistance = -1
 
 /turf/vv_edit_var(var_name, new_value)
 	var/static/list/banned_edits = list(NAMEOF_STATIC(src, x), NAMEOF_STATIC(src, y), NAMEOF_STATIC(src, z))
@@ -673,6 +679,26 @@ GLOBAL_LIST_EMPTY(station_turfs)
 			continue
 		movable_content.wash(clean_types)
 
+/turf/set_density(new_value)
+	var/old_density = density
+	. = ..()
+	if(old_density == density)
+		return
+
+	if(old_density)
+		explosive_resistance -= get_explosive_block()
+	if(density)
+		explosive_resistance += get_explosive_block()
+
+/// Wrapper around inherent_explosive_resistance
+/// We assume this proc is cold, so we can move the "what is our block" into it
+/turf/proc/get_explosive_block()
+	if(inherent_explosive_resistance != -1)
+		return inherent_explosive_resistance
+	if(explosive_resistance)
+		return initial(explosive_resistance)
+	return 0
+
 /**
  * Returns adjacent turfs to this turf that are reachable, in all cardinal directions
  *
@@ -702,3 +728,9 @@ GLOBAL_LIST_EMPTY(station_turfs)
 
 /turf/proc/TakeTemperature(temp)
 	temperature += temp
+
+// I'm sorry, this is the only way that both makes sense and is cheap
+/turf/set_explosion_block(explosion_block)
+	explosive_resistance -= get_explosive_block()
+	inherent_explosive_resistance = explosion_block
+	explosive_resistance += get_explosive_block()
diff --git a/code/modules/antagonists/blob/structures/core.dm b/code/modules/antagonists/blob/structures/core.dm
index dd92eb6ff8b..e6f27779fbf 100644
--- a/code/modules/antagonists/blob/structures/core.dm
+++ b/code/modules/antagonists/blob/structures/core.dm
@@ -32,6 +32,7 @@
 		overmind.blobstrain.on_gain()
 		update_appearance()
 	AddComponent(/datum/component/stationloving, FALSE, TRUE)
+	AddElement(/datum/element/blocks_explosives)
 	return ..()
 
 /obj/structure/blob/special/core/Destroy()
diff --git a/code/modules/antagonists/blob/structures/shield.dm b/code/modules/antagonists/blob/structures/shield.dm
index 479c40395d4..0699d70f3f2 100644
--- a/code/modules/antagonists/blob/structures/shield.dm
+++ b/code/modules/antagonists/blob/structures/shield.dm
@@ -16,6 +16,10 @@
 	fire = 90
 	acid = 90
 
+/obj/structure/blob/shield/Initialize(mapload, owner_overmind)
+	AddElement(/datum/element/blocks_explosives)
+	return ..()
+
 /obj/structure/blob/shield/scannerreport()
 	if(atmosblock)
 		return "Will prevent the spread of atmospheric changes."
diff --git a/code/modules/awaymissions/cordon.dm b/code/modules/awaymissions/cordon.dm
index 9062aa05123..eaebbaca5a9 100644
--- a/code/modules/awaymissions/cordon.dm
+++ b/code/modules/awaymissions/cordon.dm
@@ -5,7 +5,7 @@
 	icon_state = "cordon"
 	invisibility = INVISIBILITY_ABSTRACT
 	mouse_opacity = MOUSE_OPACITY_TRANSPARENT
-	explosion_block = INFINITY
+	explosive_resistance = INFINITY
 	rad_insulation = RAD_FULL_INSULATION
 	opacity = TRUE
 	density = TRUE
diff --git a/code/modules/clothing/suits/jobs.dm b/code/modules/clothing/suits/jobs.dm
index 3bdaac0aa5d..26a96193364 100644
--- a/code/modules/clothing/suits/jobs.dm
+++ b/code/modules/clothing/suits/jobs.dm
@@ -165,7 +165,6 @@
 	resistance_flags = NONE
 	species_exception = list(/datum/species/golem)
 
-// Lemom todo: and here
 /obj/item/clothing/suit/hazardvest/worn_overlays(mutable_appearance/standing, isinhands, icon_file)
 	. = ..()
 	if(!isinhands)
diff --git a/code/modules/industrial_lift/tram_walls.dm b/code/modules/industrial_lift/tram_walls.dm
index 85213b3364b..87188955533 100644
--- a/code/modules/industrial_lift/tram_walls.dm
+++ b/code/modules/industrial_lift/tram_walls.dm
@@ -26,6 +26,7 @@
 	var/slicing_duration = 100
 
 /obj/structure/tramwall/Initialize(mapload)
+	AddElement(/datum/element/blocks_explosives)
 	. = ..()
 	var/obj/item/stack/initialized_mineral = new mineral
 	set_custom_materials(initialized_mineral.mats_per_unit, mineral_amount)
diff --git a/code/modules/mapfluff/ruins/spaceruin_code/hilbertshotel.dm b/code/modules/mapfluff/ruins/spaceruin_code/hilbertshotel.dm
index a6ea1743485..3835431a331 100644
--- a/code/modules/mapfluff/ruins/spaceruin_code/hilbertshotel.dm
+++ b/code/modules/mapfluff/ruins/spaceruin_code/hilbertshotel.dm
@@ -230,7 +230,7 @@ GLOBAL_VAR_INIT(hhMysteryRoomNumber, rand(1, 999999))
 	icon_state = "hotelwall"
 	smoothing_groups = SMOOTH_GROUP_CLOSED_TURFS + SMOOTH_GROUP_HOTEL_WALLS
 	canSmoothWith = SMOOTH_GROUP_HOTEL_WALLS
-	explosion_block = INFINITY
+	explosive_resistance = INFINITY
 
 /turf/open/indestructible/hotelwood
 	desc = "Stylish dark wood with extra reinforcement. Secured firmly to the floor to prevent tampering."
@@ -250,7 +250,7 @@ GLOBAL_VAR_INIT(hhMysteryRoomNumber, rand(1, 999999))
 	base_icon_state = "bluespace"
 	baseturfs = /turf/open/space/bluespace
 	flags_1 = NOJAUNT
-	explosion_block = INFINITY
+	explosive_resistance = INFINITY
 	var/obj/item/hilbertshotel/parentSphere
 
 /turf/open/space/bluespace/Initialize(mapload)
@@ -269,7 +269,7 @@ GLOBAL_VAR_INIT(hhMysteryRoomNumber, rand(1, 999999))
 /turf/closed/indestructible/hoteldoor
 	name = "Hotel Door"
 	icon_state = "hoteldoor"
-	explosion_block = INFINITY
+	explosive_resistance = INFINITY
 	var/obj/item/hilbertshotel/parentSphere
 
 /turf/closed/indestructible/hoteldoor/proc/promptExit(mob/living/user)
diff --git a/code/modules/projectiles/guns/special/blastcannon.dm b/code/modules/projectiles/guns/special/blastcannon.dm
index a255a2dfabf..6fda91369a4 100644
--- a/code/modules/projectiles/guns/special/blastcannon.dm
+++ b/code/modules/projectiles/guns/special/blastcannon.dm
@@ -322,13 +322,7 @@
 	var/decrement = 1
 	var/atom/location = loc
 	if (reactionary)
-		if(location.density || !isturf(location))
-			decrement += location.explosion_block
-		for(var/obj/thing in location)
-			if (thing == src)
-				continue
-			var/the_block = thing.explosion_block
-			decrement += the_block == EXPLOSION_BLOCK_PROC ? thing.GetExplosionBlock() : the_block
+		decrement += location.explosive_resistance
 
 	range = max(range - decrement + 1, 0) // Already decremented by 1 in the parent. Exists so that if we pass through something with negative block it extends the range.
 	heavy_ex_range = max(heavy_ex_range - decrement, 0)
diff --git a/tgstation.dme b/tgstation.dme
index 5ad9e201cc6..36102027bf1 100644
--- a/tgstation.dme
+++ b/tgstation.dme
@@ -1079,6 +1079,7 @@
 #include "code\datums\elements\beauty.dm"
 #include "code\datums\elements\bed_tucking.dm"
 #include "code\datums\elements\befriend_petting.dm"
+#include "code\datums\elements\blocks_explosives.dm"
 #include "code\datums\elements\bsa_blocker.dm"
 #include "code\datums\elements\bump_click.dm"
 #include "code\datums\elements\can_barricade.dm"