diff --git a/library/Core.cpp b/library/Core.cpp
index df11ca5b2..ad9fdc61a 100644
--- a/library/Core.cpp
+++ b/library/Core.cpp
@@ -204,7 +204,7 @@ struct sortable
     };
 };
 
-static std::string getLuaHelp(std::string path)
+static std::string getScriptHelp(std::string path, std::string helpprefix)
 {
     ifstream script(path.c_str());
 
@@ -212,14 +212,14 @@ static std::string getLuaHelp(std::string path)
     {
         std::string help;
         if (getline(script, help) &&
-            help.substr(0,3) == "-- ")
-            return help.substr(3);
+            help.substr(0,helpprefix.length()) == helpprefix)
+            return help.substr(helpprefix.length());
     }
 
-    return "Lua script.";
+    return "No help available.";
 }
 
-static std::map<string,string> listLuaScripts(std::string path)
+static std::map<string,string> listScripts(PluginManager *plug_mgr, std::string path)
 {
     std::vector<string> files;
     getdir(path, files);
@@ -229,10 +229,16 @@ static std::map<string,string> listLuaScripts(std::string path)
     {
         if (hasEnding(files[i], ".lua"))
         {
-            std::string help = getLuaHelp(path + files[i]);
+            std::string help = getScriptHelp(path + files[i], "-- ");
 
             pset[files[i].substr(0, files[i].size()-4)] = help;
         }
+        else if (plug_mgr->eval_ruby && hasEnding(files[i], ".rb"))
+        {
+            std::string help = getScriptHelp(path + files[i], "# ");
+
+            pset[files[i].substr(0, files[i].size()-3)] = help;
+        }
     }
     return pset;
 }
@@ -275,6 +281,18 @@ static command_result runLuaScript(color_ostream &out, std::string name, vector<
     return ok ? CR_OK : CR_FAILURE;
 }
 
+static command_result runRubyScript(PluginManager *plug_mgr, std::string name, vector<string> &args)
+{
+    std::string rbcmd = "$script_args = [";
+    for (size_t i = 0; i < args.size(); i++)
+        rbcmd += "'" + args[i] + "', ";
+    rbcmd += "]\n";
+
+    rbcmd += "load './hack/scripts/" + name + ".rb'";
+
+    return plug_mgr->eval_ruby(rbcmd.c_str());
+}
+
 command_result Core::runCommand(color_ostream &out, const std::string &command)
 {
     if (!command.empty())
@@ -348,10 +366,16 @@ command_result Core::runCommand(color_ostream &con, const std::string &first, ve
                         return CR_OK;
                     }
                 }
-                auto filename = getHackPath() + "scripts/" + parts[0] + ".lua";
-                if (fileExists(filename))
+                auto filename = getHackPath() + "scripts/" + parts[0];
+                if (fileExists(filename + ".lua"))
+                {
+                    string help = getScriptHelp(filename + ".lua", "-- ");
+                    con.print("%s: %s\n", parts[0].c_str(), help.c_str());
+                    return CR_OK;
+                }
+                if (plug_mgr->eval_ruby && fileExists(filename + ".rb"))
                 {
-                    string help = getLuaHelp(filename);
+                    string help = getScriptHelp(filename + ".rb", "# ");
                     con.print("%s: %s\n", parts[0].c_str(), help.c_str());
                     return CR_OK;
                 }
@@ -499,7 +523,7 @@ command_result Core::runCommand(color_ostream &con, const std::string &first, ve
                     con.print("  %-22s- %s\n",(*iter).name.c_str(), (*iter).description.c_str());
                     con.reset_color();
                 }
-                auto scripts = listLuaScripts(getHackPath() + "scripts/");
+                auto scripts = listScripts(plug_mgr, getHackPath() + "scripts/");
                 if (!scripts.empty())
                 {
                     con.print("\nscripts:\n");
@@ -604,9 +628,11 @@ command_result Core::runCommand(color_ostream &con, const std::string &first, ve
             command_result res = plug_mgr->InvokeCommand(con, first, parts);
             if(res == CR_NOT_IMPLEMENTED)
             {
-                auto filename = getHackPath() + "scripts/" + first + ".lua";
-                if (fileExists(filename))
+                auto filename = getHackPath() + "scripts/" + first;
+                if (fileExists(filename + ".lua"))
                     res = runLuaScript(con, first, parts);
+                else if (plug_mgr->eval_ruby && fileExists(filename + ".rb"))
+                    res = runRubyScript(plug_mgr, first, parts);
                 else
                     con.printerr("%s is not a recognized command.\n", first.c_str());
             }
diff --git a/library/PluginManager.cpp b/library/PluginManager.cpp
index ae8cc755f..a314883e1 100644
--- a/library/PluginManager.cpp
+++ b/library/PluginManager.cpp
@@ -188,6 +188,7 @@ bool Plugin::load(color_ostream &con)
     plugin_shutdown = (command_result (*)(color_ostream &)) LookupPlugin(plug, "plugin_shutdown");
     plugin_onstatechange = (command_result (*)(color_ostream &, state_change_event)) LookupPlugin(plug, "plugin_onstatechange");
     plugin_rpcconnect = (RPCService* (*)(color_ostream &)) LookupPlugin(plug, "plugin_rpcconnect");
+    plugin_eval_ruby = (command_result (*)(const char*)) LookupPlugin(plug, "plugin_eval_ruby");
     index_lua(plug);
     this->name = *plug_name;
     plugin_lib = plug;
@@ -538,6 +539,7 @@ PluginManager::PluginManager(Core * core)
     const string searchstr = ".plug.dll";
 #endif
     cmdlist_mutex = new mutex();
+    eval_ruby = NULL;
     vector <string> filez;
     getdir(path, filez);
     for(size_t i = 0; i < filez.size();i++)
@@ -620,6 +622,8 @@ void PluginManager::registerCommands( Plugin * p )
     {
         belongs[cmds[i].name] = p;
     }
+    if (p->plugin_eval_ruby)
+        eval_ruby = p->plugin_eval_ruby;
     cmdlist_mutex->unlock();
 }
 
@@ -632,5 +636,7 @@ void PluginManager::unregisterCommands( Plugin * p )
     {
         belongs.erase(cmds[i].name);
     }
+    if (p->plugin_eval_ruby)
+        eval_ruby = NULL;
     cmdlist_mutex->unlock();
-}
\ No newline at end of file
+}
diff --git a/library/include/PluginManager.h b/library/include/PluginManager.h
index b76df437d..5da9fc92f 100644
--- a/library/include/PluginManager.h
+++ b/library/include/PluginManager.h
@@ -209,6 +209,7 @@ namespace DFHack
         command_result (*plugin_onupdate)(color_ostream &);
         command_result (*plugin_onstatechange)(color_ostream &, state_change_event);
         RPCService* (*plugin_rpcconnect)(color_ostream &);
+        command_result (*plugin_eval_ruby)(const char*);
     };
     class DFHACK_EXPORT PluginManager
     {
@@ -237,6 +238,7 @@ namespace DFHack
         {
             return all_plugins.size();
         }
+        command_result (*eval_ruby)(const char*);
     // DATA
     private:
         tthread::mutex * cmdlist_mutex;
diff --git a/plugins/ruby/README b/plugins/ruby/README
index 4bfc20957..619d85cf2 100644
--- a/plugins/ruby/README
+++ b/plugins/ruby/README
@@ -33,6 +33,20 @@ df/hack/ on linux), the library should be named 'libruby.dll' (.so on linux).
 You can download a tested version at http://github.com/jjyg/dfhack/downloads/
 
 
+Ruby scripts
+------------
+
+The ruby plugin allows the creation of '.rb' scripts in df/hack/scripts/.
+
+If you create such a script, e.g. 'test.rb', that will add a new dfhack console
+command 'test'.
+The script can access the console command arguments through the global variable
+'$script_args', which is an array of ruby Strings.
+
+The help string displayed in dfhack 'ls' command is the first line of the
+script, if it is a comment (starts with '# ').
+
+
 DFHack callbacks
 ----------------
 
diff --git a/plugins/ruby/ruby-autogen-defs.rb b/plugins/ruby/ruby-autogen-defs.rb
index 482cf24ff..64da12ff9 100644
--- a/plugins/ruby/ruby-autogen-defs.rb
+++ b/plugins/ruby/ruby-autogen-defs.rb
@@ -353,6 +353,7 @@ module DFHack
             end
             def empty? ; length == 0 ; end
             def flatten ; map { |e| e.respond_to?(:flatten) ? e.flatten : e }.flatten ; end
+            def index(elem=nil, &b) ; (0...length).find { |i| b ? b[self[i]] : self[i] == elem } ; end
         end
         class StaticArray < MemStruct
             attr_accessor :_tglen, :_length, :_indexenum, :_tg
diff --git a/plugins/ruby/ruby.cpp b/plugins/ruby/ruby.cpp
index e3bed78b7..f4a553380 100644
--- a/plugins/ruby/ruby.cpp
+++ b/plugins/ruby/ruby.cpp
@@ -96,8 +96,11 @@ DFhackCExport command_result plugin_shutdown ( color_ostream &out )
 }
 
 // send a single ruby line to be evaluated by the ruby thread
-static command_result plugin_eval_rb(const char *command)
+DFhackCExport command_result plugin_eval_ruby(const char *command)
 {
+    if (!r_thread)
+        return CR_FAILURE;
+
     command_result ret;
 
     // serialize 'accesses' to the ruby thread
@@ -123,11 +126,6 @@ static command_result plugin_eval_rb(const char *command)
     return ret;
 }
 
-static command_result plugin_eval_rb(std::string &command)
-{
-    return plugin_eval_rb(command.c_str());
-}
-
 DFhackCExport command_result plugin_onupdate ( color_ostream &out )
 {
     if (!r_thread)
@@ -136,7 +134,7 @@ DFhackCExport command_result plugin_onupdate ( color_ostream &out )
     if (!onupdate_active)
         return CR_OK;
 
-    return plugin_eval_rb("DFHack.onupdate");
+    return plugin_eval_ruby("DFHack.onupdate");
 }
 
 DFhackCExport command_result plugin_onstatechange ( color_ostream &out, state_change_event e)
@@ -157,7 +155,7 @@ DFhackCExport command_result plugin_onstatechange ( color_ostream &out, state_ch
 #undef SCASE
     }
 
-    return plugin_eval_rb(cmd);
+    return plugin_eval_ruby(cmd.c_str());
 }
 
 static command_result df_rubyeval(color_ostream &out, std::vector <std::string> & parameters)
@@ -178,7 +176,7 @@ static command_result df_rubyeval(color_ostream &out, std::vector <std::string>
             full += " ";
     }
 
-    return plugin_eval_rb(full);
+    return plugin_eval_ruby(full.c_str());
 }
 
 
diff --git a/scripts/slayrace.rb b/scripts/slayrace.rb
new file mode 100644
index 000000000..b58835257
--- /dev/null
+++ b/scripts/slayrace.rb
@@ -0,0 +1,21 @@
+# slay all creatures of a given race (default = goblins)
+
+race = $script_args[0] || 'GOBLIN'
+
+all_races = df.world.raws.creatures.all.map { |cr| cr.creature_id }
+raw_race = df.match_rawname(race, all_races)
+raise 'invalid race' if not raw_race
+
+race_nr = df.world.raws.creatures.all.index { |cr| cr.creature_id == raw_race }
+count = 0
+
+df.suspend {
+	df.world.units.active.each { |u|
+		if u.race == race_nr and u.body.blood_count != 0
+			u.body.blood_count = 0
+			count += 1
+		end
+	}
+}
+
+puts "slain #{count} #{raw_race}"