In a world this old, with magic having been common throughout history, there are literally thousands of magical traditions, theories, and methods. To reflect this heritage, all players with spellcasting characters should name their own spells and be able to describe the appearance of their effects fairly freely. One wizard might know magic missile as “Inoris’ slap of retribution” and cast it as a slapping hand made of energy, while another calls it “daggers of death” and causes it to manifest as white-hot daggers flying through the air.

Further, players creating spellcasting characters should be aware that a few spells—mostly of a planar nature, such as astral projection or banishment, function a bit differently in Ptolus. Your DM can provide you with details, should you need them.