diff --git a/evennia/commands/cmdhandler.py b/evennia/commands/cmdhandler.py
index d89452c3a9..b4945d5520 100644
--- a/evennia/commands/cmdhandler.py
+++ b/evennia/commands/cmdhandler.py
@@ -35,6 +35,7 @@ command line. The processing of a command works as follows:
 
 from collections import defaultdict
 from weakref import WeakValueDictionary
+from traceback import format_exc
 from copy import copy
 from twisted.internet.defer import inlineCallbacks, returnValue
 from django.conf import settings
@@ -44,6 +45,8 @@ from evennia.utils.utils import string_suggestions, to_unicode
 
 from django.utils.translation import ugettext as _
 
+_IN_GAME_ERRORS = settings.IN_GAME_ERRORS
+
 __all__ = ("cmdhandler",)
 _GA = object.__getattribute__
 _CMDSET_MERGE_CACHE = WeakValueDictionary()
@@ -76,46 +79,76 @@ CMD_LOGINSTART = "__unloggedin_look_command"
 # Function for handling multiple command matches.
 _SEARCH_AT_RESULT = utils.variable_from_module(*settings.SEARCH_AT_RESULT.rsplit('.', 1))
 
-# Output strings
+# Output strings. The first is the IN_GAME_ERRORS return, the second
+# is the normal "production message to echo to the player.
 
-_ERROR_UNTRAPPED = """
-An untrapped error occurred. Please file a bug report detailing the
-steps to reproduce. Server log time stamp is '{timestamp}'.
+_ERROR_UNTRAPPED = (
 """
-
-_ERROR_CMDSETS = """
-A cmdset merger error occurred. Please file a bug report detailing the
-steps to reproduce. Server log time stamp is '{timestamp}'.
+An untrapped error occurred.
+""",
 """
+An untrapped error occurred. Please file a bug report detailing the steps to reproduce.
+""")
 
-_ERROR_NOCMDSETS = """
+_ERROR_CMDSETS = (
+"""
+A cmdset merger-error occurred. This is often due to a syntax
+error in one of the cmdsets to merge.
+""",
+"""
+A cmdset merger-error occurred. Please file a bug report detailing the
+steps to reproduce.
+""")
+
+_ERROR_NOCMDSETS = (
+"""
+No command sets found! This is a critical bug that can have
+multiple causes.
+""",
+"""
 No command sets found! This is a sign of a critical bug.  If
 disconnecting/reconnecting doesn't" solve the problem, try to contact
-the server admin through" some other means for assistance. Server log
-time stamp is '{timestamp}'.
-"""
+the server admin through" some other means for assistance.
+""")
 
-_ERROR_CMDHANDLER = """
-A command handler bug occurred. Please file a bug report with the
-Evennia project. Include the relvant traceback from the server log at
-time stamp '{timestamp}'.
+_ERROR_CMDHANDLER = (
 """
+A command handler bug occurred. If this is not due to a local change,
+please file a bug report with the Evennia project, including the
+traceback and steps to reproduce.
+""",
+"""
+A command handler bug occurred. Please notify staff - they should
+likely file a bug report with the Evennia project.
+""")
 
 _ERROR_RECURSION_LIMIT = "Command recursion limit ({recursion_limit}) " \
                          "reached for '{raw_string}' ({cmdclass})."
 
 
-def _msg_err(receiver, string):
+def _msg_err(receiver, stringtuple):
     """
     Helper function for returning an error to the caller.
 
     Args:
         receiver (Object): object to get the error message.
-        string (str): string which will be shown to the user.
+        stringtuple (tuple): tuple with two strings - one for the
+        _IN_GAME_ERRORS mode (with the traceback) and one with the
+        production string (with a timestamp) to be shown to the user.
 
     """
-    receiver.msg(string.format(timestamp=logger.timeformat()).strip())
-
+    string = "{traceback}\n{errmsg}\n(Traceback was logged {timestamp})."
+    timestamp = logger.timeformat()
+    tracestring = format_exc()
+    #logger.log_trace()
+    if _IN_GAME_ERRORS:
+        receiver.msg(string.format(traceback=tracestring,
+                                   errmsg=stringtuple[0].strip(),
+                                   timestamp=timestamp).strip())
+    else:
+        receiver.msg(string.format(traceback=tracestring.splitlines()[-1],
+                                   errmsg=stringtuple[1].strip(),
+                                   timestamp=timestamp).strip())
 
 # custom Exceptions
 
@@ -177,7 +210,6 @@ def get_and_merge_cmdsets(caller, session, player, obj, callertype):
                     channel_cmdset = yield CHANNELHANDLER.get_cmdset(player)
                 returnValue(channel_cmdset)
             except Exception:
-                logger.log_trace()
                 _msg_err(caller, _ERROR_CMDSETS)
                 raise ErrorReported
 
@@ -221,7 +253,6 @@ def get_and_merge_cmdsets(caller, session, player, obj, callertype):
                         cset.duplicates = True if cset.duplicates is None else cset.duplicates
                 returnValue(local_obj_cmdsets)
             except Exception:
-                logger.log_trace()
                 _msg_err(caller, _ERROR_CMDSETS)
                 raise ErrorReported
 
@@ -235,7 +266,6 @@ def get_and_merge_cmdsets(caller, session, player, obj, callertype):
             try:
                 yield obj.at_cmdset_get()
             except Exception:
-                logger.log_trace()
                 _msg_err(caller, _ERROR_CMDSETS)
                 raise ErrorReported
             try:
@@ -323,7 +353,6 @@ def get_and_merge_cmdsets(caller, session, player, obj, callertype):
     except ErrorReported:
         raise
     except Exception:
-        logger.log_trace()
         _msg_err(caller, _ERROR_CMDSETS)
         raise ErrorReported
 
@@ -449,7 +478,6 @@ def cmdhandler(called_by, raw_string, _testing=False, callertype="session", sess
             returnValue(ret)
 
         except Exception:
-            logger.log_trace()
             _msg_err(caller, _ERROR_UNTRAPPED)
             raise ErrorReported
 
@@ -579,10 +607,8 @@ def cmdhandler(called_by, raw_string, _testing=False, callertype="session", sess
 
         except Exception:
             # We should not end up here. If we do, it's a programming bug.
-            logger.log_trace()
             _msg_err(error_to, _ERROR_UNTRAPPED)
 
     except Exception:
         # This catches exceptions in cmdhandler exceptions themselves
-        logger.log_trace()
         _msg_err(error_to, _ERROR_CMDHANDLER)
diff --git a/evennia/commands/cmdsethandler.py b/evennia/commands/cmdsethandler.py
index 237084bf21..14445cf171 100644
--- a/evennia/commands/cmdsethandler.py
+++ b/evennia/commands/cmdsethandler.py
@@ -66,6 +66,7 @@ the 'Fishing' set. Fishing from a boat? No problem!
 from builtins import object
 from future.utils import raise_
 import sys
+from traceback import format_exc
 from importlib import import_module
 from inspect import trace
 from django.conf import settings
@@ -78,6 +79,29 @@ __all__ = ("import_cmdset", "CmdSetHandler")
 
 _CACHED_CMDSETS = {}
 _CMDSET_PATHS = utils.make_iter(settings.CMDSET_PATHS)
+_IN_GAME_ERRORS = settings.IN_GAME_ERRORS
+
+# Output strings
+
+_ERROR_CMDSET_IMPORT = _(
+"""{traceback}
+Error loading cmdset '{path}'
+(Traceback was logged {timestamp})""")
+
+_ERROR_CMDSET_KEYERROR = _(
+"""Error loading cmdset: No cmdset class '{classname}' in '{path}'.
+(Traceback was logged {timestamp})""")
+
+_ERROR_CMDSET_SYNTAXERROR = _(
+"""{traceback}
+SyntaxError encountered when loading cmdset '{path}'.
+(Traceback was logged {timestamp})""")
+
+_ERROR_CMDSET_EXCEPTION = _(
+"""{traceback}
+Compile/Run error when loading cmdset '{path}'.",
+(Traceback was logged {timestamp})""")
+
 
 class _ErrorCmdSet(CmdSet):
     """
@@ -160,25 +184,34 @@ def import_cmdset(path, cmdsetobj, emit_to_obj=None, no_logging=False):
                 cmdsetclass = cmdsetclass(cmdsetobj)
             errstring = ""
             return cmdsetclass
-        except ImportError as e:
+        except ImportError as err:
             logger.log_trace()
-            errstring += _("\nError loading cmdset {path}: \"{error}\"")
-            errstring = errstring.format(path=python_path, error=e)
+            errstring += _ERROR_CMDSET_IMPORT
+            if _IN_GAME_ERRORS:
+                errstring = errstring.format(path=python_path, traceback=format_exc(), timestamp=logger.timeformat())
+            else:
+                errstring = errstring.format(path=python_path, traceback=err, timestamp=logger.timeformat())
             break
         except KeyError:
             logger.log_trace()
-            errstring += _("\nError in loading cmdset: No cmdset class '{classname}' in {path}.")
-            errstring = errstring.format(classname=classname, path=python_path)
+            errstring += _ERROR_CMDSET_KEYERROR
+            errstring = errstring.format(classname=classname, path=python_path, timestamp=logger.timeformat())
             break
-        except SyntaxError as e:
+        except SyntaxError as err:
             logger.log_trace()
-            errstring += _("\nSyntaxError encountered when loading cmdset '{path}': \"{error}\".")
-            errstring = errstring.format(path=python_path, error=e)
+            errstring += _ERROR_CMDSET_SYNTAXERROR
+            if _IN_GAME_ERRORS:
+                errstring = errstring.format(path=python_path, traceback=format_exc(), timestamp=logger.timeformat())
+            else:
+                errstring = errstring.format(path=python_path, traceback=err, timestamp=logger.timeformat())
             break
-        except Exception as e:
+        except Exception as err:
             logger.log_trace()
-            errstring += _("\nCompile/Run error when loading cmdset '{path}': \"{error}\".")
-            errstring = errstring.format(path=python_path, error=e)
+            errstring += _ERROR_CMDSET_EXCEPTION
+            if _IN_GAME_ERRORS:
+                errstring = errstring.format(path=python_path, traceback=format_exc(), timestamp=logger.timeformat())
+            else:
+                errstring = errstring.format(path=python_path, traceback=err, timestamp=logger.timeformat())
             break
 
     if errstring:
@@ -189,7 +222,7 @@ def import_cmdset(path, cmdsetobj, emit_to_obj=None, no_logging=False):
             if emit_to_obj and not ServerConfig.objects.conf("server_starting_mode"):
                 emit_to_obj.msg(errstring)
         err_cmdset = _ErrorCmdSet()
-        err_cmdset.errmessage = errstring +  _("\n (See log for details.)")
+        err_cmdset.errmessage = errstring
         return err_cmdset
 
 # classes
diff --git a/evennia/settings_default.py b/evennia/settings_default.py
index e8e7bd5f81..076ebd9913 100644
--- a/evennia/settings_default.py
+++ b/evennia/settings_default.py
@@ -23,6 +23,9 @@ import sys
 
 # This is the name of your game. Make it catchy!
 SERVERNAME = "Evennia"
+# Lockdown mode will cut off the game from any external connections
+# and only allow connections from localhost. Requires a cold reboot.
+LOCKDOWN_MODE = False
 # Activate telnet service
 TELNET_ENABLED = True
 # A list of ports the Evennia telnet server listens on Can be one or many.
@@ -204,6 +207,11 @@ MAX_CONNECTION_RATE = 2
 MAX_COMMAND_RATE = 80
 # The warning to echo back to users if they send commands too fast
 COMMAND_RATE_WARNING ="You entered commands too fast. Wait a moment and try again."
+# If this is true, errors and tracebacks from the engine will be
+# echoed as text in-game as well as to the log. This can speed up
+# debugging. Showing full tracebacks to regular users could be a
+# security problem - this should *not* be active in a production game!
+IN_GAME_ERRORS = False
 
 ######################################################################
 # Evennia Database config