Include that an empty string is expected

* don't allow one-way and two-way entrances to be connected to each other

* add special handling for the tower hq nodes since they share the same parent region

docs/network protocol.md

@@ -756,8 +756,8 @@ Tags are represented as a list of strings, the common client tags follow:
 ### DeathLink
 A special kind of Bounce packet that can be supported by any AP game. It targets the tag "DeathLink" and carries the following data:
 
-| Name   | Type  | Notes                                                                                                                                                  |
-|--------|-------|--------------------------------------------------------------------------------------------------------------------------------------------------------|
-| time   | float | Unix Time Stamp of time of death.                                                                                                                      |
-| cause  | str   | Optional. Text to explain the cause of death. When provided, or checked, this should contain the player name, ex. "Berserker was run over by a train." |
-| source | str   | Name of the player who first died. Can be a slot name, but can also be a name from within a multiplayer game.                                          |
+| Name   | Type  | Notes                                                                                                                                                                            |
+|--------|-------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| time   | float | Unix Time Stamp of time of death.                                                                                                                                                |
+| cause  | str   | Optional. Text to explain the cause of death. When provided, or checked, if the string is non-empty, it should contain the player name, ex. "Berserker was run over by a train." |
+| source | str   | Name of the player who first died. Can be a slot name, but can also be a name from within a multiplayer game.                                                                    |

worlds/messenger/options.py

@@ -51,6 +51,12 @@ class TransitionPlando(PlandoConnections):
     entrances = frozenset(RANDOMIZED_CONNECTIONS.keys())
     exits = frozenset(RANDOMIZED_CONNECTIONS.values())
 
+    @classmethod
+    def can_connect(cls, entrance: str, exit: str) -> bool:
+        if entrance != "Glacial Peak - Left" and entrance.lower() in cls.exits:
+            return exit.lower() in cls.entrances
+        return exit.lower() not in cls.entrances
+
 
 class Logic(Choice):
     """

worlds/messenger/transitions.py

@@ -30,10 +30,19 @@ def connect_plando(world: "MessengerWorld", plando_connections: TransitionPlando
 
     for plando_connection in plando_connections:
         # get the connecting regions
-        reg1 = world.get_region(plando_connection.entrance)
+        # need to handle these special because the names are unique but have the same parent region
+        if plando_connection.entrance in ("Artificer", "Tower HQ"):
+            reg1 = world.get_region("Tower HQ")
+            if plando_connection.entrance == "Artificer":
+                dangling_exit = world.get_entrance("Artificer's Portal")
+            else:
+                dangling_exit = world.get_entrance("Artificer's Challenge")
+            reg1.exits.remove(dangling_exit)
+        else:
+            reg1 = world.get_region(plando_connection.entrance)
+            remove_dangling_exit(reg1)
+        
         reg2 = world.get_region(plando_connection.exit)
-
-        remove_dangling_exit(reg1)
         remove_dangling_entrance(reg2)
         # connect the regions
         reg1.connect(reg2)