The heat mirage is a simple illusion spell that is used to augment the desert's natural illusory properties. When cast upon an area that is already affected by a natural mirage, it enhances that image and produces auditory and olfactory illusions as well. Anyone who fails a saving throw vs. spell will believe that the illusion is an actual oasis.
This spell is often used to lure unwary travelers to an area so that they may be ambushed. Because the illusion isn't dispelled until someone tries to drink from the “oasis,” bandits can hide within the affected area and spring upon their unwitting victims.
Good wizards use this spell to lure foolish travelers away from dangerous areas or creatures. While not exactly the most polite method, those wizards valuing their privacy find that the heat mirage works much better than an open meeting.
Notes: Uncommon in Arabian settings; otherwise very rare.