diff --git a/src/Lobby.cc b/src/Lobby.cc
index 8a2857d3..cab4d8e8 100644
--- a/src/Lobby.cc
+++ b/src/Lobby.cc
@@ -674,6 +674,51 @@ shared_ptr<Client> Lobby::find_client(const string* identifier, uint64_t serial_
   throw out_of_range("client not found");
 }
 
+Lobby::JoinError Lobby::join_error_for_client(std::shared_ptr<Client> c, const std::string* password) const {
+  if (this->count_clients() >= this->max_clients) {
+    return JoinError::FULL;
+  }
+  if (!this->version_is_allowed(c->version()) && !c->config.check_flag(Client::Flag::DEBUG_ENABLED)) {
+    return JoinError::VERSION_CONFLICT;
+  }
+  if (this->is_game()) {
+    if (this->check_flag(Flag::QUEST_IN_PROGRESS)) {
+      return JoinError::QUEST_IN_PROGRESS;
+    }
+    if (this->check_flag(Flag::BATTLE_IN_PROGRESS)) {
+      return JoinError::BATTLE_IN_PROGRESS;
+    }
+    if (this->mode == GameMode::SOLO) {
+      return JoinError::SOLO;
+    }
+    if (!(c->license->flags & License::Flag::FREE_JOIN_GAMES)) {
+      if (password && !this->password.empty() && (*password != this->password)) {
+        return JoinError::INCORRECT_PASSWORD;
+      }
+      auto p = c->character();
+      if (p->disp.stats.level < this->min_level) {
+        return JoinError::LEVEL_TOO_LOW;
+      }
+      if (p->disp.stats.level > this->max_level) {
+        return JoinError::LEVEL_TOO_HIGH;
+      }
+      if (this->quest) {
+        size_t num_clients = this->count_clients() + 1;
+        if (!c->can_see_quest(this->quest, this->difficulty, num_clients) ||
+            !c->can_play_quest(this->quest, this->difficulty, num_clients)) {
+          return JoinError::NO_ACCESS_TO_QUEST;
+        }
+      }
+    }
+    // Only prevent joining during loading if the client is actually trying to
+    // join (not just loading the game list)
+    if (password && this->any_client_loading()) {
+      return JoinError::LOADING;
+    }
+  }
+  return JoinError::ALLOWED;
+}
+
 uint8_t Lobby::game_event_for_lobby_event(uint8_t lobby_event) {
   if (lobby_event > 7) {
     return 0;
diff --git a/src/Lobby.hh b/src/Lobby.hh
index 1034fe59..2307cc0d 100644
--- a/src/Lobby.hh
+++ b/src/Lobby.hh
@@ -228,6 +228,21 @@ struct Lobby : public std::enable_shared_from_this<Lobby> {
       const std::string* identifier = nullptr,
       uint64_t serial_number = 0);
 
+  enum class JoinError {
+    ALLOWED = 0,
+    FULL,
+    VERSION_CONFLICT,
+    QUEST_IN_PROGRESS,
+    BATTLE_IN_PROGRESS,
+    LOADING,
+    SOLO,
+    INCORRECT_PASSWORD,
+    LEVEL_TOO_LOW,
+    LEVEL_TOO_HIGH,
+    NO_ACCESS_TO_QUEST,
+  };
+  JoinError join_error_for_client(std::shared_ptr<Client> c, const std::string* password) const;
+
   bool item_exists(uint8_t floor, uint32_t item_id) const;
   std::shared_ptr<FloorItem> find_item(uint8_t floor, uint32_t item_id) const;
   void add_item(uint8_t floor, const ItemData& item, float x, float z, uint16_t visibility_flags);
diff --git a/src/ReceiveCommands.cc b/src/ReceiveCommands.cc
index 4ff415af..1dccabf5 100644
--- a/src/ReceiveCommands.cc
+++ b/src/ReceiveCommands.cc
@@ -2390,66 +2390,56 @@ static void on_10(shared_ptr<Client> c, uint16_t, uint32_t, string& data) {
         send_lobby_message_box(c, "$C6You cannot join this\ngame because it no\nlonger exists.");
         break;
       }
-      if (!game->is_game()) {
-        send_lobby_message_box(c, "$C6You cannot join this\ngame because it is\nnot a game.");
-        break;
-      }
-      if (game->count_clients() >= game->max_clients) {
-        send_lobby_message_box(c, "$C6You cannot join this\ngame because it is\nfull.");
-        break;
-      }
-      if (!game->version_is_allowed(c->version()) && !c->config.check_flag(Client::Flag::DEBUG_ENABLED)) {
-        send_lobby_message_box(c, "$C6You cannot join this\ngame because it is\nfor a different\nversion of PSO.");
-        break;
-      }
-      if (game->check_flag(Lobby::Flag::QUEST_IN_PROGRESS)) {
-        send_lobby_message_box(c, "$C6You cannot join this\ngame because a\nquest is already\nin progress.");
-        break;
-      }
-      if (game->check_flag(Lobby::Flag::BATTLE_IN_PROGRESS)) {
-        send_lobby_message_box(c, "$C6You cannot join this\ngame because a\nbattle is already\nin progress.");
-        break;
-      }
-      if (game->any_client_loading()) {
-        send_lobby_message_box(c, "$C6You cannot join this\ngame because\nanother player is\ncurrently loading.\nTry again soon.");
-        break;
-      }
-      if (game->mode == GameMode::SOLO) {
-        send_lobby_message_box(c, "$C6You cannot join this\n game because it is\na Solo Mode game.");
-        break;
-      }
-
-      if (!(c->license->flags & License::Flag::FREE_JOIN_GAMES)) {
-        if (!game->password.empty() && (password != game->password)) {
+      switch (game->join_error_for_client(c, &password)) {
+        case Lobby::JoinError::ALLOWED:
+          if (!s->change_client_lobby(c, game)) {
+            throw logic_error("client cannot join game after all preconditions satisfied");
+          }
+          if (game->is_game()) {
+            c->config.set_flag(Client::Flag::LOADING);
+            // If no one was in the game before, then there's no leader to send the
+            // item state - send it to the joining player (who is now the leader)
+            if (game->count_clients() == 1) {
+              // No one was in the game before, so the object and enemy state is lost;
+              // regenerate it as if the game was just created
+              game->load_maps();
+              c->config.set_flag(Client::Flag::SHOULD_SEND_ARTIFICIAL_ITEM_STATE);
+            }
+          }
+          break;
+        case Lobby::JoinError::FULL:
+          send_lobby_message_box(c, "$C6You cannot join this\ngame because it is\nfull.");
+          break;
+        case Lobby::JoinError::VERSION_CONFLICT:
+          send_lobby_message_box(c, "$C6You cannot join this\ngame because it is\nfor a different\nversion of PSO.");
+          break;
+        case Lobby::JoinError::QUEST_IN_PROGRESS:
+          send_lobby_message_box(c, "$C6You cannot join this\ngame because a\nquest is already\nin progress.");
+          break;
+        case Lobby::JoinError::BATTLE_IN_PROGRESS:
+          send_lobby_message_box(c, "$C6You cannot join this\ngame because a\nbattle is already\nin progress.");
+          break;
+        case Lobby::JoinError::LOADING:
+          send_lobby_message_box(c, "$C6You cannot join this\ngame because\nanother player is\ncurrently loading.\nTry again soon.");
+          break;
+        case Lobby::JoinError::SOLO:
+          send_lobby_message_box(c, "$C6You cannot join this\ngame because it is\na Solo Mode game.");
+          break;
+        case Lobby::JoinError::INCORRECT_PASSWORD:
           send_lobby_message_box(c, "$C6Incorrect password.");
           break;
-        }
-        auto p = c->character();
-        if (p->disp.stats.level < game->min_level) {
+        case Lobby::JoinError::LEVEL_TOO_LOW:
           send_lobby_message_box(c, "$C6Your level is too\nlow to join this\ngame.");
           break;
-        }
-        if (p->disp.stats.level > game->max_level) {
+        case Lobby::JoinError::LEVEL_TOO_HIGH:
           send_lobby_message_box(c, "$C6Your level is too\nhigh to join this\ngame.");
           break;
-        }
-        if (game->quest && !c->can_play_quest(game->quest, game->difficulty, game->count_clients() + 1)) {
+        case Lobby::JoinError::NO_ACCESS_TO_QUEST:
           send_lobby_message_box(c, "$C6You don't have access\nto the quest in progress\nin this game, or there\nis no space for another\nplayer in the quest.");
           break;
-        }
-      }
-
-      if (!s->change_client_lobby(c, game)) {
-        throw logic_error("client cannot join game after all preconditions satisfied");
-      }
-      c->config.set_flag(Client::Flag::LOADING);
-      // If no one was in the game before, then there's no leader to send the
-      // item state - send it to the joining player (who is now the leader)
-      if (game->count_clients() == 1) {
-        // No one was in the game before, so the object and enemy state is lost;
-        // regenerate it as if the game was just created
-        game->load_maps();
-        c->config.set_flag(Client::Flag::SHOULD_SEND_ARTIFICIAL_ITEM_STATE);
+        default:
+          send_lobby_message_box(c, "$C6You cannot join this\ngame.");
+          break;
       }
       break;
     }
diff --git a/src/SendCommands.cc b/src/SendCommands.cc
index cd92160a..a88ca17f 100644
--- a/src/SendCommands.cc
+++ b/src/SendCommands.cc
@@ -1413,13 +1413,15 @@ void send_game_menu_t(
           e.flags |= 0x20;
           break;
         case GameMode::SOLO:
-          // These should only be visible to other BB clients
-          e.flags |= 0x04; // Grayed (but not disabled apparently)
           e.episode = 0x10 | episode_num;
           break;
         default:
           throw logic_error("invalid game mode");
       }
+      // On BB, gray out games that can't be joined
+      if ((c->version() == Version::BB_V4) && (l->join_error_for_client(c, nullptr) != Lobby::JoinError::ALLOWED)) {
+        e.flags |= 0x04;
+      }
     }
     e.name.encode(l->name, c->language());
   }