diff --git a/.github/workflows/maindev.yml b/.github/workflows/maindev.yml
new file mode 100644
index 00000000..8f4e02ea
--- /dev/null
+++ b/.github/workflows/maindev.yml
@@ -0,0 +1,38 @@
+name: Test Multiplayer Mod
+
+on:
+  push:
+  pull_request:
+  workflow_dispatch:
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    
+    steps:
+    - uses: actions/checkout@v4
+    
+    - name: Setup Lua
+      uses: leafo/gh-actions-lua@v10
+      with:
+        luaVersion: "5.4"
+
+    - name: Setup LuaRocks
+      run: |
+        sudo apt-get update
+        sudo apt-get install -y luarocks lua5.4 liblua5.4-dev
+
+    - name: Install Busted
+      run: |
+        luarocks --lua-version=5.4 install --local busted
+        echo "$HOME/.luarocks/bin" >> "$GITHUB_PATH"
+    
+    - name: Syntax of all Lua files
+      run: |
+        for file in $(find . -type f -name "*.lua" -not -path "./.git/*"); do
+          echo "Checking $file"
+          lua -e "assert(loadfile('$file'))"
+        done
+
+    - name: Run Busted tests
+      run: busted --pattern='_test%.lua$' tests
diff --git a/core.lua b/core.lua
index 8391e4a9..548377d1 100644
--- a/core.lua
+++ b/core.lua
@@ -19,6 +19,7 @@ MP.LOBBY = {
 	type = "",
 	config = {}, -- Now set in MP.reset_lobby_config
 	deck = {
+		back_key = "b_red",
 		back = "Red Deck",
 		sleeve = "sleeve_casl_none",
 		stake = 1,
@@ -171,6 +172,7 @@ function MP.reset_lobby_config(persist_ruleset_and_gamemode)
 		weekly = nil,
 		custom_seed = "random",
 		different_decks = false,
+		back_key = "b_red",
 		back = "Red Deck",
 		sleeve = "sleeve_casl_none",
 		stake = 1,
@@ -217,6 +219,7 @@ function MP.reset_game_states()
 		prevent_eval = false,
 		round_ended = false,
 		duplicate_end = false,
+		pvp_blind_started = false,
 		misprint_display = "",
 		spent_total = 0,
 		spent_before_shop = 0,
diff --git a/lib/card_utils.lua b/lib/card_utils.lua
index a4662688..67457bb0 100644
--- a/lib/card_utils.lua
+++ b/lib/card_utils.lua
@@ -84,10 +84,40 @@ function MP.UTILS.run_for_each_phantom_joker(key, func)
 	end
 end
 
-function MP.UTILS.get_deck_key_from_name(_name)
+function MP.UTILS.get_deck_key_from_name(deck_name_or_key)
+	if not deck_name_or_key then
+		return "b_red"
+	end
+
+	-- Already a valid key?
+	if G.P_CENTERS[deck_name_or_key] and G.P_CENTERS[deck_name_or_key].set == "Back" then
+		return deck_name_or_key
+	end
+
+	-- Search by name (localized or raw)
 	for k, v in pairs(G.P_CENTERS) do
-		if v.name == _name then return k end
+		if v.set == "Back" then
+			local loc_name = localize({type = 'name_text', key = k, set = 'Back'})
+			if v.name == deck_name_or_key or loc_name == deck_name_or_key then
+				return k
+			end
+		end
+	end
+
+	sendErrorMessage("MP.UTILS.get_deck_key_from_name: Could not find deck for '" .. tostring(deck_name_or_key) .. "'", "MULTIPLAYER")
+	return "b_red"
+end
+
+function MP.UTILS.get_deck_name_from_key(deck_key)
+	if not deck_key then
+		return "Red Deck"
 	end
+
+	if G.P_CENTERS[deck_key] and G.P_CENTERS[deck_key].set == "Back" then
+		return G.P_CENTERS[deck_key].name or localize({type = 'name_text', key = deck_key, set = 'Back'})
+	end
+
+	return "Red Deck"
 end
 
 function MP.UTILS.get_culled_pool(_type, _rarity, _legendary, _append)
diff --git a/networking/action_handlers.lua b/networking/action_handlers.lua
index 3f52ad00..f601cfff 100644
--- a/networking/action_handlers.lua
+++ b/networking/action_handlers.lua
@@ -112,6 +112,25 @@ function Game:update(dt)
 			handle_reconnect_timeout("Reconnection failed.\nReturning to main menu.")
 		end
 	end
+		-- Auto-detect stuck outside PvP blind
+	if MP.LOBBY.code and MP.is_pvp_boss() and not MP.GAME.pvp_blind_started then
+
+		-- Check if opponent is already in PvP blind (has "playing" in their location)
+		if MP.GAME.enemy and MP.GAME.enemy.location and string.find(MP.GAME.enemy.location, "playing") then
+			sendDebugMessage("Auto-detected stuck outside PvP blind, recovering...", "MULTIPLAYER")
+
+			-- Trigger the same unstuck logic that the button uses
+			if G.FUNCS.mp_unstuck_blind then
+				G.FUNCS.mp_unstuck_blind()
+			end
+		end
+	end
+	
+	-- Also reset the flag when leaving PvP state
+	if MP.LOBBY.code and not MP.is_pvp_boss() and MP.GAME.pvp_blind_started then
+		MP.GAME.pvp_blind_started = false
+	end
+	
 	return _disconnect_gupdate(self, dt)
 end
 
@@ -247,9 +266,18 @@ local function begin_pvp_blind()
 end
 
 local function action_start_blind()
+
+	-- Reset state
 	MP.GAME.ready_blind = false
 	MP.GAME.timer_started = false
 	MP.GAME.timer = MP.LOBBY.config.timer_base_seconds
+	MP.GAME.pvp_blind_started = true  -- New flag
+	
+	-- Clear any pending stuck state
+	if MP.GAME.stuck_outside_pvp then
+		MP.GAME.stuck_outside_pvp = nil
+	end
+	
 	MP.UI.start_pvp_countdown(begin_pvp_blind)
 end
 
@@ -328,11 +356,42 @@ end
 
 local function action_stop_game()
 	MP.enemy_disconnect_countdown = nil
-	if G.STAGE ~= G.STAGES.MAIN_MENU then
-		G.FUNCS.go_to_menu()
-		MP.UI.update_connection_status()
-		MP.reset_game_states()
-	end
+	
+	-- Show the notification
+	attention_text({
+		text = "Opponent left the lobby",
+		scale = 0.8,
+		hold = 2,
+		align = "cm",
+		offset = { x = 0, y = 0 },
+		major = G.ROOM_ATTACH,
+	})
+	
+	-- Event system for delay
+	G.E_MANAGER:add_event(Event({
+		trigger = "after",
+		delay = 2.0,
+		func = function()
+			-- Clear lobby state first
+			MP.LOBBY.code = nil
+			MP.LOBBY.connected = false
+			MP.LOBBY.in_game = false
+			
+			-- Force reset to main menu
+			G.STATE = G.STATES.MENU
+			G.STATE_COMPLETE = false
+			
+			-- Clear any remaining UI
+			if G.OVERLAY_MENU then
+				G.FUNCS.exit_overlay_menu()
+			end
+			
+			-- Refresh the main menu UI
+			set_main_menu_UI()
+			
+			return true
+		end,
+	}))
 end
 
 local function action_end_pvp()
@@ -427,14 +486,32 @@ local function action_lobby_options(options)
 			parsed_v = tonumber(v)
 		end
 
-		MP.LOBBY.config[k] = parsed_v
+		-- Handle deck keys
+		if k == "back_key" then
+			MP.LOBBY.config.back_key = parsed_v
+			MP.LOBBY.config.back = MP.UTILS.get_deck_name_from_key(parsed_v) or parsed_v
+		elseif k == "back" then
+			local key = MP.UTILS.get_deck_key_from_name(parsed_v)
+			if key then
+				MP.LOBBY.config.back_key = key
+				MP.LOBBY.config.back = MP.UTILS.get_deck_name_from_key(key)
+			else
+				MP.LOBBY.config.back = parsed_v
+			end
+		else
+			MP.LOBBY.config[k] = parsed_v
+		end
+
 		if MP.UI.update_lobby_option_toggle then MP.UI.update_lobby_option_toggle(k) end
 		::continue::
 	end
+
 	if different_decks_before ~= MP.LOBBY.config.different_decks then
-		G.FUNCS.exit_overlay_menu() -- throw out guest from any menu.
+		G.FUNCS.exit_overlay_menu()
 	end
+
 	MP.ACTIONS.update_player_usernames() -- render new DECK button state
+
 end
 
 local function action_send_phantom(key)
@@ -1178,7 +1255,6 @@ function Game:update(dt)
 				end
 				return
 			end
-
 			local parsedAction = json.decode(msg)
 
 			if not ((parsedAction.action == "keepAlive") or (parsedAction.action == "keepAliveAck")) then
diff --git a/tests/action_stop_game_test.lua b/tests/action_stop_game_test.lua
new file mode 100644
index 00000000..8c43fef4
--- /dev/null
+++ b/tests/action_stop_game_test.lua
@@ -0,0 +1,102 @@
+local function load_action_stop_game(env)
+	local f = assert(io.open("networking/action_handlers.lua", "r"))
+	local src = f:read("*a")
+	f:close()
+
+	local start_idx = assert(src:find("local function action_stop_game%(%)"))
+	local next_fn_idx = assert(src:find("\nlocal function action_end_pvp%(%)", start_idx))
+	local snippet = src:sub(start_idx, next_fn_idx - 1)
+
+	local chunk = assert(load(snippet .. "\nreturn action_stop_game", "action_stop_game_snippet", "t", env))
+	return chunk()
+end
+
+describe("action_stop_game", function()
+	it("sets message and schedules delayed cleanup", function()
+		local attention
+		local added_event
+
+		local env = {
+			MP = {
+				enemy_disconnect_countdown = { end_time = 10 },
+				LOBBY = { code = "ABCD", connected = true, in_game = true },
+			},
+			G = {
+				ROOM_ATTACH = {},
+				E_MANAGER = {
+					add_event = function(_, ev)
+						added_event = ev
+					end,
+				},
+			},
+			attention_text = function(args)
+				attention = args
+			end,
+			Event = function(def)
+				return def
+			end,
+			set_main_menu_UI = function()
+			end,
+		}
+
+		local action_stop_game = load_action_stop_game(env)
+		action_stop_game()
+
+		assert(env.MP.enemy_disconnect_countdown == nil)
+		assert(attention ~= nil)
+		assert(attention.text == "Opponent left the lobby")
+		assert(added_event.delay == 2.0)
+		assert(type(added_event.func) == "function")
+	end)
+
+	it("applies delayed state reset and returns true", function()
+		local overlay_closed = 0
+		local menu_refreshed = 0
+		local added_event
+
+		local env = {
+			MP = {
+				enemy_disconnect_countdown = nil,
+				LOBBY = { code = "ABCD", connected = true, in_game = true },
+			},
+			G = {
+				ROOM_ATTACH = {},
+				OVERLAY_MENU = true,
+				STATE = "INGAME",
+				STATE_COMPLETE = true,
+				STATES = { MENU = "MENU" },
+				E_MANAGER = {
+					add_event = function(_, ev)
+						added_event = ev
+					end,
+				},
+				FUNCS = {
+					exit_overlay_menu = function()
+						overlay_closed = overlay_closed + 1
+					end,
+				},
+			},
+			attention_text = function()
+			end,
+			Event = function(def)
+				return def
+			end,
+			set_main_menu_UI = function()
+				menu_refreshed = menu_refreshed + 1
+			end,
+		}
+
+		local action_stop_game = load_action_stop_game(env)
+		action_stop_game()
+		local ok = added_event.func()
+
+		assert(ok == true)
+		assert(env.MP.LOBBY.code == nil)
+		assert(env.MP.LOBBY.connected == false)
+		assert(env.MP.LOBBY.in_game == false)
+		assert(env.G.STATE == "MENU")
+		assert(env.G.STATE_COMPLETE == false)
+		assert(overlay_closed == 1)
+		assert(menu_refreshed == 1)
+	end)
+end)
diff --git a/ui/lobby/deck_stake_button.lua b/ui/lobby/deck_stake_button.lua
index 340b8323..c227e849 100644
--- a/ui/lobby/deck_stake_button.lua
+++ b/ui/lobby/deck_stake_button.lua
@@ -2,10 +2,20 @@ local Disableable_Button = MP.UI.Disableable_Button
 
 -- Component for deck selection button in lobby
 function MP.UI.create_lobby_deck_button(text_scale, back, stake)
+	-- Determine the correct deck key (prefer stored key, fallback to converting name)
+	local deck_key
+	if MP.LOBBY.deck.back_key then
+		deck_key = MP.LOBBY.deck.back_key
+	elseif MP.LOBBY.config.back_key then
+		deck_key = MP.LOBBY.config.back_key
+	else
+		deck_key = MP.UTILS.get_deck_key_from_name(back) or "b_red"
+	end
+
 	local deck_labels = {
 		localize({
 			type = "name_text",
-			key = MP.UTILS.get_deck_key_from_name(back),
+			key = deck_key,
 			set = "Back",
 		}),
 		localize({
@@ -42,4 +52,4 @@ function MP.UI.create_lobby_deck_button(text_scale, back, stake)
 			enabled_ref_value = "different_decks",
 		})
 	end
-end
+end
\ No newline at end of file
diff --git a/ui/lobby/lobby.lua b/ui/lobby/lobby.lua
index 8f899aa9..14a50c49 100644
--- a/ui/lobby/lobby.lua
+++ b/ui/lobby/lobby.lua
@@ -39,7 +39,15 @@ end
 
 function G.UIDEF.create_UIBox_lobby_menu()
 	local text_scale = 0.45
-	local back = MP.LOBBY.config.different_decks and MP.LOBBY.deck.back or MP.LOBBY.config.back
+	
+	-- Get deck key (prefer back_key, fallback to name)
+	local back_key
+	if MP.LOBBY.config.different_decks then
+		back_key = MP.LOBBY.deck.back_key or MP.LOBBY.deck.back
+	else
+		back_key = MP.LOBBY.config.back_key or MP.LOBBY.config.back
+	end
+	local back_name = MP.UTILS.get_deck_name_from_key(back_key) or "Red Deck"
 	local stake = MP.LOBBY.config.different_decks and MP.LOBBY.deck.stake or MP.LOBBY.config.stake
 
 	local t = {
@@ -86,7 +94,7 @@ function G.UIDEF.create_UIBox_lobby_menu()
 										col = true,
 									}) or nil,
 									MP.UI.create_spacer(),
-									MP.UI.create_lobby_deck_button(text_scale, back, stake),
+									MP.UI.create_lobby_deck_button(text_scale, back_name, stake),
 									MP.UI.create_spacer(),
 									MP.UI.create_players_section(text_scale),
 									MP.UI.create_spacer(),
@@ -263,12 +271,15 @@ function G.FUNCS.lobby_start_run(e, args)
 	if MP.LOBBY.config.different_decks == false then G.FUNCS.copy_host_deck() end
 
 	local challenge = nil
-	if MP.LOBBY.deck.back == "Challenge Deck" then
+	local deck_key = MP.LOBBY.deck.back_key or MP.LOBBY.deck.back
+	if deck_key == "Challenge Deck" or deck_key == "b_challenge_deck" then
 		challenge = G.CHALLENGES[get_challenge_int_from_id(MP.LOBBY.deck.challenge)]
 	else
-		G.GAME.viewed_back = G.P_CENTERS[MP.UTILS.get_deck_key_from_name(MP.LOBBY.deck.back)]
+		G.GAME.viewed_back = G.P_CENTERS[deck_key]
 	end
 
+
+
 	G.FUNCS.start_run(e, {
 		mp_start = true,
 		challenge = challenge,
@@ -297,7 +308,8 @@ function Back:generate_UI(other, ui_scale, min_dims, challenge)
 end
 
 function G.FUNCS.copy_host_deck()
-	MP.LOBBY.deck.back = MP.LOBBY.config.back
+	MP.LOBBY.deck.back_key = MP.LOBBY.config.back_key or MP.LOBBY.config.back
+	MP.LOBBY.deck.back = MP.LOBBY.config.back  -- keep for long term
 	MP.LOBBY.deck.cocktail = MP.LOBBY.config.cocktail
 	MP.LOBBY.deck.sleeve = MP.LOBBY.config.sleeve
 	MP.LOBBY.deck.stake = MP.LOBBY.config.stake
@@ -375,17 +387,23 @@ G.FUNCS.start_run = function(e, args)
 				chosen_stake = MP.DECK.MAX_STAKE
 			end
 			if MP.LOBBY.is_host then
-				MP.LOBBY.config.back = args.challenge and "Challenge Deck"
-					or (args.deck and args.deck.name)
-					or G.GAME.viewed_back.name
-				MP.LOBBY.config.stake = chosen_stake
-				MP.LOBBY.config.sleeve = G.viewed_sleeve
-				MP.LOBBY.config.challenge = args.challenge and args.challenge.id or ""
-				send_lobby_options()
-			end
-			MP.LOBBY.deck.back = args.challenge and "Challenge Deck"
-				or (args.deck and args.deck.name)
-				or G.GAME.viewed_back.name
+					local deck_key = args.challenge and "Challenge Deck"
+						or (args.deck and MP.UTILS.get_deck_key_from_name(args.deck.name))
+						or (G.GAME.viewed_back and G.GAME.viewed_back.key)
+						or "b_red"
+					MP.LOBBY.config.back_key = deck_key
+					MP.LOBBY.config.back = deck_key  -- long
+					MP.LOBBY.config.stake = chosen_stake
+					MP.LOBBY.config.sleeve = G.viewed_sleeve
+					MP.LOBBY.config.challenge = args.challenge and args.challenge.id or ""
+					send_lobby_options()
+				end
+				local deck_key = args.challenge and "Challenge Deck"
+					or (args.deck and MP.UTILS.get_deck_key_from_name(args.deck.name))
+					or (G.GAME.viewed_back and G.GAME.viewed_back.key)
+					or "b_red"
+				MP.LOBBY.deck.back_key = deck_key
+				MP.LOBBY.deck.back = deck_key  -- long
 			MP.LOBBY.deck.stake = chosen_stake
 			MP.LOBBY.deck.sleeve = G.viewed_sleeve
 			MP.LOBBY.deck.challenge = args.challenge and args.challenge.id or ""