diff --git a/mods/lzr_laser/blocks.lua b/mods/lzr_laser/blocks.lua
index 0497252..2f4a341 100644
--- a/mods/lzr_laser/blocks.lua
+++ b/mods/lzr_laser/blocks.lua
@@ -198,6 +198,10 @@ local register_element = function(subname, def, options)
 	else
 		def_core.after_place_node = full_update
 	end
+	if options.not_walkable_if_off then
+		def_core.walkable = false
+	end
+
 	def_core.description = S("@1 (fixed)", def.description)
 	def_core.after_dig_node = full_update
 	def_core._after_rotate = after_rotate
@@ -217,8 +221,14 @@ local register_element = function(subname, def, options)
 	minetest.register_node("lzr_laser:"..subname, def_core)
 
 	local def_core_on
+
 	if options.activate ~= false then
 		def_core_on = table.copy(def_core)
+		if options.not_walkable_if_off then
+			def_core_on.walkable = true
+		elseif options.not_walkable_if_on then
+			def_core_on.walkable = false
+		end
 		def_core_on.description = S("@1 (fixed, active)", def.description)
 		def_core_on._lzr_active = nil
 		def_core_on._lzr_inactive = "lzr_laser:"..subname
@@ -477,6 +487,95 @@ register_element("detector", {
 	sounds = lzr_sounds.node_sound_wood_defaults(),
 }, { allow_take = true, is_detector = true })
 
+-- Is non-walkable if off,
+-- and walkable if on.
+register_element("skull_cursed", {
+	description = S("Cursed Skull"),
+	paramtype2 = "facedir",
+	--[[ TODO
+	tiles_off = {
+		"lzr_laser_cskull_top.png^lzr_laser_fixed.png",
+		"lzr_laser_cskull_bottom.png^lzr_laser_fixed.png",
+		"lzr_laser_cskull_side.png^lzr_laser_fixed.png",
+		"lzr_laser_cskull_side.png^lzr_laser_fixed.png",
+		"lzr_laser_cskull_back.png^lzr_laser_fixed.png",
+		"lzr_laser_cskull_front.png^lzr_laser_fixed.png",
+	},
+	tiles_on = {
+		"lzr_laser_cskull_on_top.png^lzr_laser_fixed.png",
+		"lzr_laser_cskull_on_bottom.png^lzr_laser_fixed.png",
+		"lzr_laser_cskull_on_side.png^lzr_laser_fixed.png",
+		"lzr_laser_cskull_on_side.png^lzr_laser_fixed.png",
+		"lzr_laser_cskull_on_back.png^lzr_laser_fixed.png",
+		"lzr_laser_cskull_on_front.png^lzr_laser_fixed.png",
+	},
+	tiles_takable_off = {
+		"lzr_laser_cskull_top.png",
+		"lzr_laser_cskull_bottom.png",
+		"lzr_laser_cskull_side.png",
+		"lzr_laser_cskull_side.png",
+		"lzr_laser_cskull_back.png",
+		"lzr_laser_cskull_front.png",
+	},
+	tiles_takable_on = {
+		"lzr_laser_cskull_on_top.png",
+		"lzr_laser_cskull_on_bottom.png",
+		"lzr_laser_cskull_on_side.png",
+		"lzr_laser_cskull_on_side.png",
+		"lzr_laser_cskull_on_back.png",
+		"lzr_laser_cskull_on_front.png",
+	},
+	]]
+	light_source_on = 5,
+	groups = { rotatable = 2, laser_block = 1 },
+	on_rotate = screwdriver.rotate_simple,
+	sounds = lzr_sounds.node_sound_stone_defaults(),
+}, { allow_take = true, not_walkable_if_off = true })
+
+-- Is walkable if off,
+-- and non-walkable if on.
+register_element("skull_shy", {
+	description = S("Shy Skull"),
+	paramtype2 = "facedir",
+	--[[ TODO
+	tiles_off = {
+		"lzr_laser_sskull_top.png^lzr_laser_fixed.png",
+		"lzr_laser_sskull_bottom.png^lzr_laser_fixed.png",
+		"lzr_laser_sskull_side.png^lzr_laser_fixed.png",
+		"lzr_laser_sskull_side.png^lzr_laser_fixed.png",
+		"lzr_laser_sskull_back.png^lzr_laser_fixed.png",
+		"lzr_laser_sskull_front.png^lzr_laser_fixed.png",
+	},
+	tiles_on = {
+		"lzr_laser_sskull_on_top.png^lzr_laser_fixed.png",
+		"lzr_laser_sskull_on_bottom.png^lzr_laser_fixed.png",
+		"lzr_laser_sskull_on_side.png^lzr_laser_fixed.png",
+		"lzr_laser_sskull_on_side.png^lzr_laser_fixed.png",
+		"lzr_laser_sskull_on_back.png^lzr_laser_fixed.png",
+		"lzr_laser_sskull_on_front.png^lzr_laser_fixed.png",
+	},
+	tiles_takable_off = {
+		"lzr_laser_sskull_top.png",
+		"lzr_laser_sskull_bottom.png",
+		"lzr_laser_sskull_side.png",
+		"lzr_laser_sskull_side.png",
+		"lzr_laser_sskull_back.png",
+		"lzr_laser_sskull_front.png",
+	},
+	tiles_takable_on = {
+		"lzr_laser_sskull_on_top.png",
+		"lzr_laser_sskull_on_bottom.png",
+		"lzr_laser_sskull_on_side.png",
+		"lzr_laser_sskull_on_side.png",
+		"lzr_laser_sskull_on_back.png",
+		"lzr_laser_sskull_on_front.png",
+	},
+	]]
+	light_source_on = 5,
+	groups = { rotatable = 2, laser_block = 1 },
+	on_rotate = screwdriver.rotate_simple,
+	sounds = lzr_sounds.node_sound_stone_defaults(),
+}, { allow_take = true, not_walkable_if_on = true })
 
 minetest.register_node("lzr_laser:barricade", {
 	description = S("Barricade"),
diff --git a/mods/lzr_laser/mod.conf b/mods/lzr_laser/mod.conf
index a7cc677..13fff2c 100644
--- a/mods/lzr_laser/mod.conf
+++ b/mods/lzr_laser/mod.conf
@@ -1,2 +1,2 @@
 name = lzr_laser
-depends = lzr_globals, lzr_sounds
+depends = lzr_globals, lzr_sounds, screwdriver2
diff --git a/mods/lzr_laser/physics.lua b/mods/lzr_laser/physics.lua
index 54f991b..7e6a29e 100644
--- a/mods/lzr_laser/physics.lua
+++ b/mods/lzr_laser/physics.lua
@@ -50,6 +50,16 @@ function lzr_laser.add_laser(pos, dir, varea, vdata)
 		vdata[vi] = minetest.get_content_id("lzr_laser:laser_"..place_dirstring)
 		pos = vector.add(pos, dir)
 		return {{pos, dir}}
+	-- Laser through skull
+	elseif minetest.get_item_group(nodename, "skull_shy") > 0 or minetest.get_item_group(nodename, "skull_cursed") > 0 then
+		local def = minetest.registered_nodes[nodename]
+		local active = def._lzr_active
+		if active then
+			-- Activate skull node
+			vdata[vi] = minetest.get_content_id(def._lzr_active)
+		end
+		pos = vector.add(pos, dir)
+		return {{pos, dir}}
 	-- Mirror laser
 	elseif minetest.get_item_group(nodename, "mirror") > 0 then
 		local mirror_dir = lzr_laser.get_mirrored_laser_dir(pos, dir)