Lfun:	set_chance - set the spell chance in a monster

Synopsis:
	void set_chance(int spell_chance)

Description:
	The set_chance function sets the spall chance in a monster. The chance
	controls the spells of it during a combat. The chance may range from
	0 (no spells at all) to 100 (each combat round a spell).

Return value:
	none

Examples:
	set_chance(30);

See also: monster/set_spell_dam, monster/set_spell_mess1, monster/set_spell_mess2