Traceback (most recent call last):
  File "c:\evennia\evennia\evennia\commands\cmdhandler.py", line 509, in _run_command
    ret = yield cmd.func()
  File "C:\Evennia\tutorial\commands\command.py", line 302, in func
    tickerhandler.add(15, rules.skill_combat(caller, target))
  File "c:\evennia\evennia\evennia\scripts\tickerhandler.py", line 496, in add
    obj, path, callfunc = self._get_callback(callback)
  File "c:\evennia\evennia\evennia\scripts\tickerhandler.py", line 341, in _get_callback
    raise TypeError("%s is not a callable function or method." %  callback)
TypeError: None is not a callable function or method.

An untrapped error occurred.

--

    def func(self):
        "implements the actual functionality"
        caller = self.caller
        target = caller.search(self.target)
        # Beginning of the validation checks
        if not target:
            caller.msg("Hit whom?")
            return
        if not utils.inherits_from(target, 'typeclasses.characters.Character'):
            caller.msg("This is not a valid target.")
            return
        if target == caller:
            caller.msg("You affectionately pat yourself on the back.")
            caller.location.msg_contents("{} affectionately pats themselves on the back.".format(caller.name), exclude=[caller])
            return
        tickerhandler.add(15, rules.skill_combat(caller, target))

---
def skill_combat(*args):
    """
    This determines outcome of combat.
    The one who rolls under theri combat skill AND
    higher than their opponent's roll hits.
    Args:
        *args:

    Returns:

    """
    char1, char2 = args
    roll1, roll2 = roll_hit(), roll_hit()
    failtext = "You are hit by %s for %i damage!"
    wintext = "You hit %s for %i damage!"
    char1.msg("{} is char1. Their combat score is {}.".format(char1.name,char1.db.skills['combat']))
    char1.msg("{} is char2. Their combat score is {}.".format(char2.name, char2.db.skills['combat']))
    char1.msg("Roll1 = {}".format(roll1))
    char1.msg("Roll2 = {}".format(roll2))
    if char1.db.skills['combat'] >= roll1 > roll2:
        # Char 1 hits
        dmg = roll_dmg() + char1.db.str
        char1.msg(wintext % (char2, dmg))
        char2.msg(failtext % (char1, dmg))
        char2.db.hp['Current'] -= dmg
        check_defeat(char2)
        update_prompt(char2)
    elif char2.db.skills['combat'] >= roll2 > roll1:
        # char 2 hits
        dmg = roll_dmg() + char2.db.str
        char1.msg(failtext % (char2, dmg))
        char1.db.hp['Current'] -= dmg
        check_defeat(char1)
        char2.msg(wintext % (char1, dmg))
        update_prompt(char1)
    else:
        # draw
        drawtext = "Neither of you can find an opening."
        char1.msg(drawtext)
        char2.msg(drawtext)