diff --git a/luprex/core/cpp/gui.cpp b/luprex/core/cpp/gui.cpp
index 4e037023..79e713ec 100644
--- a/luprex/core/cpp/gui.cpp
+++ b/luprex/core/cpp/gui.cpp
@@ -35,6 +35,12 @@ bool Gui::has_action(const std::string &action) const {
     return false;
 }
 
+std::string Gui::get_action(int index) {
+    if ((index < 0) || (index >= elts_.size())) {
+        return "";
+    }
+    return elts_[index].action();
+}
 
 LuaDefine(gui_menu_item, "c") {
     Gui *gui = Gui::fetch_global_pointer(L);
diff --git a/luprex/core/cpp/gui.hpp b/luprex/core/cpp/gui.hpp
index 91881350..a45e8aef 100644
--- a/luprex/core/cpp/gui.hpp
+++ b/luprex/core/cpp/gui.hpp
@@ -36,6 +36,7 @@ public:
     void clear() { elts_.clear(); }
     bool has_action(const std::string &action) const;
     void menu_item(const std::string &action, const std::string &label);
+    std::string get_action(int index);
 
     // Put a pointer to a gui into the lua registry.
     //
diff --git a/luprex/core/cpp/invocation.cpp b/luprex/core/cpp/invocation.cpp
index 75388681..53b10fdd 100644
--- a/luprex/core/cpp/invocation.cpp
+++ b/luprex/core/cpp/invocation.cpp
@@ -36,6 +36,9 @@ Invocation::Invocation() : kind_(KIND_INVALID), actor_(0), place_(0) {}
 Invocation::Invocation(Kind kind, int64_t actor, int64_t place, const std::string &action, const InvocationData &data) 
     : kind_(kind), actor_(actor), place_(place), action_(action), data_(data) {}
 
+Invocation::Invocation(Kind kind, int64_t actor, int64_t place, const std::string &action) 
+    : kind_(kind), actor_(actor), place_(place), action_(action) {}
+
 void Invocation::serialize(StreamBuffer *sb) const {
     sb->write_uint8(kind_);
     sb->write_int64(actor_);
diff --git a/luprex/core/cpp/invocation.hpp b/luprex/core/cpp/invocation.hpp
index 0f6cc3f5..0f970694 100644
--- a/luprex/core/cpp/invocation.hpp
+++ b/luprex/core/cpp/invocation.hpp
@@ -33,7 +33,9 @@ private:
 public:
     Invocation();
     Invocation(Kind kind, int64_t actor, int64_t place, const std::string &action, const InvocationData &data);
-
+    Invocation(Kind kind, int64_t actor, int64_t place, const std::string &action);
+    
+    bool valid() const { return kind_ != KIND_INVALID; }
     Kind kind() const { return kind_; }
     int64_t actor() const { return actor_; }
     int64_t place() const { return place_; }
diff --git a/luprex/core/cpp/lpxclient.cpp b/luprex/core/cpp/lpxclient.cpp
index f420345a..63821a8a 100644
--- a/luprex/core/cpp/lpxclient.cpp
+++ b/luprex/core/cpp/lpxclient.cpp
@@ -96,29 +96,14 @@ public:
     }
 
     void do_lua_command(const StringVec &words) {
-        if (words.size() != 2) {
-            stdostream() << "lua command (lua) takes a single string" << std::endl;
-            return;
-        }
-        const std::string &exp = words[1];
-        InvocationData dummyresult;
-        Invocation inv(Invocation::KIND_LUA, actor_id_, actor_id_, exp, dummyresult);
-        send_invocation(inv);
+        send_invocation(Invocation(Invocation::KIND_LUA, actor_id_, actor_id_, words[1]));
     }
 
     void do_syntax_command(const StringVec &words) {
-        stdostream() << "Syntax Error: ";
-        for (int i = 1; i < int(words.size()); i++) {
-            stdostream() << words[i] << " ";
-        }
-        stdostream() << std::endl;
+        stdostream() << "Syntax Error: " << words[1] << std::endl;
     }
 
     void do_view_command(const StringVec &cmd) {
-        if (cmd.size() != 1) {
-            stdostream() << "view command takes no arguments" << std::endl;
-            return;
-        }
         for (int64_t id : world_->get_near(actor_id_, 100, true)) {
             const Tangible *tan = world_->tangible_get(id);
             const AnimStep &aqback = tan->anim_queue_.back();
@@ -127,18 +112,9 @@ public:
     }
 
     void do_menu_command(const StringVec &cmd) {
-        int64_t id;
-        if (cmd.size() == 1) {
-            id = actor_id_;
-        } else if (cmd.size() == 2) {
-            id = util::strtoint(cmd[1], -1);
-        } else {
-            stdostream() << "menu command expects a tangible ID or defaults to actor_id" << std::endl;
-            return;
-        }
         world_to_asynchronous();
-        gui_place_ = id;
-        world_->update_gui(actor_id_, id, &gui_);
+        gui_place_ = util::strtoint(cmd[1], actor_id_);
+        world_->update_gui(actor_id_, gui_place_, &gui_);
         int index = 0;
         for (const GuiElt &elt : gui_.elts()) {
             stdostream() << index << " " << elt.label() << std::endl;
@@ -147,32 +123,17 @@ public:
     }
 
     void do_choose_command(const StringVec &cmd) {
-        int64_t index;
-        if (cmd.size() == 1) {
-            index = util::strtoint(cmd[0], -1);
-        } else {
-            stdostream() << "choose command consists of a single menu line number" << std::endl;
+        std::string action = gui_.get_action(util::strtoint(cmd[1], -1));
+        if (action == "") {
+            stdostream() << "Invalid menu item #" << std::endl;
             return;
         }
-        const Gui::EltVec &elts = gui_.elts();
-        if ((index < 0) || (index >= int(elts.size()))) {
-            stdostream() << "No menu item #" << index << std::endl;
-            return;
-        }
-        std::string action = elts[index].action();
         stdostream() << "Invoking plan: " << action << std::endl;
-        InvocationData dummyresult;
-        dummyresult["flavor"] = "chocolate";
-        dummyresult["color"] = "blue";
-        Invocation inv(Invocation::KIND_PLAN, actor_id_, gui_place_, action, dummyresult);
+        Invocation inv(Invocation::KIND_PLAN, actor_id_, gui_place_, action);
         send_invocation(inv);
     }
 
     void do_quit_command(const util::StringVec &words) {
-        if (words.size() != 1) {
-            stdostream() << "quit command takes no arguments" << std::endl;
-            return;
-        }
         abandon_server();
         stop_driver();
     }
@@ -184,9 +145,9 @@ public:
         else if (words[0] == "view") do_view_command(words);
         else if (words[0] == "menu") do_menu_command(words);
         else if (words[0] == "quit") do_quit_command(words);
-        else if (util::validinteger(words[0])) do_choose_command(words);
+        else if (words[0] == "choose") do_choose_command(words);
         else {
-            stdostream() << "Unknown command: " << words[0] << std::endl;
+            stdostream() << "Unsupported command: " << words[0] << std::endl;
         }
     }
 
diff --git a/luprex/core/cpp/lpxserver.cpp b/luprex/core/cpp/lpxserver.cpp
index 7bc9314a..40ef2f96 100644
--- a/luprex/core/cpp/lpxserver.cpp
+++ b/luprex/core/cpp/lpxserver.cpp
@@ -43,29 +43,14 @@ public:
     }
 
     void do_lua_command(const util::StringVec &words) {
-        if (words.size() != 2) {
-            stdostream() << "lua command (lua) takes a single string" << std::endl;
-            return;
-        }
-        const std::string &exp = words[1];
-        InvocationData dummyresult;
-        Invocation inv(Invocation::KIND_LUA, admin_id_, admin_id_, exp, dummyresult);
-        master_->invoke(inv);
+        master_->invoke(Invocation(Invocation::KIND_LUA, admin_id_, admin_id_, words[1]));
     }
 
     void do_syntax_command(const util::StringVec &words) {
-        stdostream() << "Syntax Error: ";
-        for (int i = 1; i < int(words.size()); i++) {
-            stdostream() << words[i] << " ";
-        }
-        stdostream() << std::endl;
+        stdostream() << "Syntax Error: " << words[1] << std::endl;
     }
 
     void do_quit_command(const util::StringVec &words) {
-        if (words.size() != 1) {
-            stdostream() << "quit command takes no arguments" << std::endl;
-            return;
-        }
         stop_driver();
     }
 
@@ -75,7 +60,7 @@ public:
         else if (words[0] == "syntax") do_syntax_command(words);
         else if (words[0] == "quit") do_quit_command(words);
         else {
-            stdostream() << "Unknown command: " << words[0] << std::endl;
+            stdostream() << "Unsupported command: " << words[0] << std::endl;
         }
     }
 
diff --git a/luprex/core/cpp/luaconsole.cpp b/luprex/core/cpp/luaconsole.cpp
index de8b6a83..4e0e315b 100644
--- a/luprex/core/cpp/luaconsole.cpp
+++ b/luprex/core/cpp/luaconsole.cpp
@@ -38,6 +38,65 @@ LuaConsole::StringVec LuaConsole::get_command() {
     return result;
 }
 
+void LuaConsole::synerr(const std::string &msg) {
+    words_.clear();
+    words_.push_back("syntax");
+    words_.push_back(msg);
+}
+
+void LuaConsole::simplify(const StringVec &words) {
+    words_ = words;
+    if (words.size() == 0) {
+        return;
+    } else if (util::validinteger(words[0])) {
+        if (words.size() == 1) {
+            words_.clear();
+            words_.push_back("choose");
+            words_.push_back(words[0]);
+        } else {
+            synerr("/choose command takes no arguments");
+        }
+    } else if (words[0] == "choose") {
+        if ((words.size() == 2)&&(util::validinteger(words[1]))) {
+            // OK
+        } else {
+            synerr("/choose [menu-line-number]");
+        }
+    } else if (words[0] == "view") {
+        if (words.size() != 1) {
+            synerr("/view takes no arguments");
+        }
+    } else if (words[0] == "menu") {
+        if (words.size() == 1) {
+            words_.push_back("-");
+        } else if ((words.size() == 2)&&(util::validinteger(words[1]))) {
+            // OK
+        } else {
+            synerr("/menu [optional-tangible-id]");
+        }
+    } else if (words[0] == "quit") {
+        if (words.size() != 1) {
+            synerr("/quit takes no arguments");
+        }
+    } else if (words[0] == "snap") {
+        if (words.size() != 1) {
+            synerr("/snap takes no arguments");
+        }
+    } else if (words[0] == "roll") {
+        if (words.size() != 1) {
+            synerr("/roll takes no arguments");
+        }
+    } else if (words[0] == "tick") {
+        if ((words.size() == 2)&&(util::validinteger(words[1]))) {
+            // OK
+        } else {
+            synerr("/tick [optional-timestamp]");
+        }
+    } else {
+        synerr("unrecognized command");
+    }
+}
+
 void LuaConsole::clear_raw_input() {
     raw_input_ = "";
     lines_ = 0;
@@ -52,10 +111,11 @@ void LuaConsole::add(std::string line) {
     raw_input_ += '\n';
     lines_ += 1;
     prompt_ = ">> ";
+    words_.clear();
 
     // Try to interpret it as a slash-command.
     if ((lines_ == 1)&&(raw_input_[0] == '/')) {
-        words_ = split_words(raw_input_.substr(1));
+        simplify(split_words(raw_input_.substr(1)));
         clear_raw_input();
         return;
     }
diff --git a/luprex/core/cpp/luaconsole.hpp b/luprex/core/cpp/luaconsole.hpp
index 73cac7e8..2b8ae23e 100644
--- a/luprex/core/cpp/luaconsole.hpp
+++ b/luprex/core/cpp/luaconsole.hpp
@@ -8,23 +8,28 @@
 //    1. Print the prompt suggested by 'get_prompt'.
 //    2. Read a line of text from stdin.
 //    3. Add the line to the LuaConsole using 'add'.
-//    4. Get the command words using 'get_command'.
+//    4. Get the command word using get_command.
 //    5. If the command is empty, do nothing.
-//    6. If the command is nonempty, execute it.
+//    6. If the command is nonempty, get the args and execute it.
 //
-// The LuaConsole expects you to type one of three things:
+// The LuaConsole expects you to type a lua command, or one
+// of the following slash-commands:
 //
-//   * Valid Lua Code.
-//   * Valid Lua Code preceded by '=' as shorthand for 'return'
-//   * A slash-command.
+//    /quit               - exit the program
+//    /view               - display the nearby tangibles
+//    /menu [tanid]       - display the menu for tangible 
+//    /snap               - snapshot current state
+//    /roll               - rollback to previous state
+//    /tick [timevalue]   - advance the simulation clock
+//    /1234               - choose menu item 1234
 //
-// The 'get_command' returned by the luaconsole can be one of
-// the following:
+// If you type anything else, the LuaConsole will generate a
+// syntax error.  Note that not all of the commands above are
+// supported in all interpreters.
 //
-//    empty vector   - still collecting input: do nothing.
-//    lua <expr>     - found a lua command: execute it as lua.
-//    syntax <words> - detected a syntax error: print the error.
-//    word word ...  - read a slash-command: execute the command.
+// Once a command has been typed (or a syntax error has been
+// typed), the LuaConsole will return the command.  The command
+// can be fetched using command(), int_arg(), and str_arg()
 //
 //////////////////////////////////////////////////////
 
@@ -42,10 +47,12 @@ private:
     lua_State *lua_state_;
     std::string raw_input_;
     int lines_;
-    StringVec words_;
     std::string prompt_;
+    StringVec words_;
 
     void clear_raw_input();
+    void simplify(const StringVec &words);
+    void synerr(const std::string &msg);
 
 public:
     LuaConsole();
@@ -57,15 +64,14 @@ public:
     //
     const std::string &get_prompt() { return prompt_; }
     
-    // Fetch the command to execute.
+    // Get the command words.
+    //
+    // Note that the command words may not be exactly what
+    // the user typed.  Typically, the LuaConsole simplifies
+    // the command before returning it to the caller.
     //
-    // You should fetch the command after calling 'add'.
-    // Returns the empty vector if there is no command.
-    // If there is a command, the first word is the command word.
-    // See the file comment for certain built-in command words.
-    // 
     StringVec get_command();
-
+    
     // Add a line of text that was just read from the console.
     //
     void add(std::string line);
diff --git a/luprex/core/cpp/textgame.cpp b/luprex/core/cpp/textgame.cpp
index 72ca4b32..67649b75 100644
--- a/luprex/core/cpp/textgame.cpp
+++ b/luprex/core/cpp/textgame.cpp
@@ -29,32 +29,15 @@ private:
     int64_t gui_place_;
     int64_t actor_id_;
     
-
     void do_lua_command(const StringVec &words) {
-        assert(world_->stack_is_clear());
-        if (words.size() != 2) {
-            stdostream() << "lua command (lua) takes a single string" << std::endl;
-            return;
-        }
-        const std::string &exp = words[1];
-        InvocationData dummyresult;
-        Invocation inv(Invocation::KIND_LUA, actor_id_, actor_id_, exp, dummyresult);
-        world_->invoke(inv);
+        world_->invoke(Invocation(Invocation::KIND_LUA, actor_id_, actor_id_, words[1]));
     }
 
     void do_syntax_command(const StringVec &words) {
-        stdostream() << "Syntax Error: ";
-        for (int i = 1; i < int(words.size()); i++) {
-            stdostream() << words[i] << " ";
-        }
-        stdostream() << std::endl;
+        stdostream() << "Syntax Error: " << words[1] << std::endl;
     }
 
     void do_view_command(const StringVec &cmd) {
-        if (cmd.size() != 1) {
-            stdostream() << "v command (view) takes no arguments" << std::endl;
-            return;
-        }
         for (int64_t id : world_->get_near(actor_id_, 100, true)) {
             const Tangible *tan = world_->tangible_get(id);
             const AnimStep &aqback = tan->anim_queue_.back();
@@ -63,17 +46,8 @@ private:
     }
 
     void do_menu_command(const StringVec &cmd) {
-        int64_t id;
-        if (cmd.size() == 1) {
-            id = actor_id_;
-        } else if (cmd.size() == 2) {
-            id = util::strtoint(cmd[1], -1);
-        } else {
-            stdostream() << "m command (menu) expects a tangible ID or defaults to actor_id" << std::endl;
-            return;
-        }
-        gui_place_ = id;
-        world_->update_gui(actor_id_, id, &gui_);
+        gui_place_ = util::strtoint(cmd[1], actor_id_);
+        world_->update_gui(actor_id_, gui_place_, &gui_);
         int index = 0;
         for (const GuiElt &elt : gui_.elts()) {
             stdostream() << index << " " << elt.label() << std::endl;
@@ -82,60 +56,29 @@ private:
     }
 
     void do_choose_command(const StringVec &cmd) {
-        int64_t index;
-        if (cmd.size() == 1) {
-            index = util::strtoint(cmd[0], -1);
-        } else {
-            stdostream() << "c command (choose) expects a menu line number" << std::endl;
+        std::string action = gui_.get_action(util::strtoint(cmd[1], -1));
+        if (action == "") {
+            stdostream() << "Invalid menu item #" << std::endl;
             return;
         }
-        const Gui::EltVec &elts = gui_.elts();
-        if ((index < 0) || (index >= int(elts.size()))) {
-            stdostream() << "No menu item #" << index << std::endl;
-            return;
-        }
-        std::string action = elts[index].action();
-        stdostream() << "Invoking plan: " << action << std::endl;
-        InvocationData dummyresult;
-        dummyresult["flavor"] = "chocolate";
-        dummyresult["color"] = "blue";
-        Invocation inv(Invocation::KIND_PLAN, actor_id_, gui_place_, action, dummyresult);
+        Invocation inv(Invocation::KIND_PLAN, actor_id_, gui_place_, action);
+        stdostream() << "Invoking: " << inv.debug_string() << std::endl;
         world_->invoke(inv);
     }
 
-
     void do_snapshot_command(const StringVec &cmd) {
-        if (cmd.size() != 1) {
-            stdostream() << "s command (snapshot) takes no arguments" << std::endl;
-            return;
-        }
         world_->snapshot();
     }
 
     void do_rollback_command(const StringVec &cmd) {
-        if (cmd.size() != 1) {
-            stdostream() << "r command (rollback) takes no arguments" << std::endl;
-            return;
-        }
         world_->rollback();
     }
 
     void do_tick_command(const StringVec &cmd) {
-        int64_t clock;
-        if (cmd.size() == 2) {
-            clock = util::strtoint(cmd[1], -1);
-        } else {
-            stdostream() << "t command (tick) expects a time value" << std::endl;
-            return;
-        }
-        world_->run_scheduled_threads(clock);
+        world_->run_scheduled_threads(util::strtoint(cmd[1], -1));
     }
 
     void do_quit_command(const StringVec &cmd) {
-        if (cmd.size() != 1) {
-            stdostream() << "q command (quit) takes no arguments" << std::endl;
-            return;
-        }
         actor_id_ = 0;
     }
 
@@ -149,9 +92,9 @@ private:
         else if (words[0] == "snap") do_snapshot_command(words);
         else if (words[0] == "roll") do_rollback_command(words);
         else if (words[0] == "tick") do_tick_command(words);
-        else if (util::validinteger(words[0])) do_choose_command(words);
+        else if (words[0] == "choose") do_choose_command(words);
         else {
-            stdostream() << "Unknown command: " << words[0] << std::endl;
+            stdostream() << "Unsupported command: " << words[0] << std::endl;
         }
     }
 
diff --git a/luprex/core/cpp/util.cpp b/luprex/core/cpp/util.cpp
index 3b565b16..be8d8807 100644
--- a/luprex/core/cpp/util.cpp
+++ b/luprex/core/cpp/util.cpp
@@ -142,6 +142,16 @@ StringVec split(const std::string &s, char sep) {
     return result;
 }
 
+std::string join(const StringVec &strs, const std::string &sep) {
+    if (strs.empty()) return "";
+    std::ostringstream oss;
+    oss << strs[0];
+    for (int i = 1; i < strs.size(); i++) {
+        oss << sep << strs[i];
+    }
+    return oss.str();
+}
+
 std::string repeat_string(const std::string &a, int n) {
     int len = a.size();
     std::string result(len * n, ' ');
diff --git a/luprex/core/cpp/util.hpp b/luprex/core/cpp/util.hpp
index b3b8cab1..9bc5b216 100644
--- a/luprex/core/cpp/util.hpp
+++ b/luprex/core/cpp/util.hpp
@@ -63,6 +63,9 @@ std::string hash_to_hex(const HashValue &hash);
 // Split a string into multiple strings
 StringVec split(const std::string &s, char sep);
 
+// Join multiple strings into one string
+std::string join(const StringVec &strs, std::string sep);
+
 // Return N repetitions of string A
 std::string repeat_string(const std::string &a, int n);