These call on what is believed to be the ultimate source of power, which differs from spell to spell.
Quite literally, they call up that power and ask for permission to use this influence for a stated purpose.
Meddling with this power and calling up negative forces is extremely unwise and very foolish.
Spells for selfish personal power or to gain power over others will often backfire on the unwary and may cause damage to the individual who casts them.
Invocations of positive forces can do no harm, except that the results can sometimes be highly disconcerting due to the sheer energy created, although the eventual outcome may be good.
