From the NannyMUD documentation

LAST CHANGE

2000-12-15

FUNCTION

NAME
        hit_player - attempt to do damage to a living object


LOCATION
	/obj/living.c

SYNTAX
	int hit_player(int damage, int ignoreflag, string dam_type,
                       object who, int ignore_ac);

DESCRIPTION
	This function is used to attack a living object and attempt to
	do damage amount of hit point damage to the living.  An attack
	on a non-PK (player-killing) character by another interactive
	character will fail unless a true value is passed as a second
	argument.

	The third argument to hit_player is damage_type. See damage_types
	for more information on what diffrent types you can set.
	See also protection_ and sensitivity_.

        The fourth argument is the object doing the damage.

	The fifth argument will, if non-zero, cause the target's ac
	protection to be ignored.


RETURN VALUES
	The actual damage done to the living object is returned.  Due
	to armour and other causes, this may be lower than the
	passed value.


NOTE
	Do not use the ignoreflag without obtaining permission from a
	35++ wizard.  Use of the ignoreflag is logged.

	Use of ignore_ac flag requires approval as well.


NOTE
	This function is meant for combat usage and other code which can
	kill the victim, such as poison, falling into pits, and the like.


NOTE
	Almost all combat occurs in this function.  Because this may
	change in the future, if you redefine this function do not copy
	the information over.  Instead use ::hit_player(damage) to
	pass the damage on to the living.  You may wish to modify the
	damage beforehand depending on your purposes.  See the
	inheritance(LPC) doc to understand the '::'.


NOTE
	Uses for this function include custom spells and the like.


NOTE
	It is rather common that you wish to create a monster that cannot
	be killed, but that won't be used for target practise by guilds
	using skills. One easy way to do so is to re-define hit_player so
	that it returns -1.

	hit_player() { return -1; }