Sun Magic is about power. Power to endure, power to persevere, and power to change. Wizards that choose to learn the supplementary school of Sun magic will charge up their strength and focus their efforts to cast stronger, more accurate main school spells, and even manipulate those spells into other forms.
The focus of the Sun School is primarily on enchantments & mutations. Enchantments from the Sun School operate in the same manner as all other enchantments in the game. At the basic level they just give boosts to accuracy and damage but at higher levels they will include mutates and larger bonuses. Mutation spells are a big part of Sun Magic, such as this Mutate Kraken into Inferno Kraken! One of the differences between Sun School enchantments and other in-game enchantments is that cards enchanted with Sun School cards disappear after combat is resolved. Sun School cards must be used on damage cards (not drains), and cannot be used on Rank 0 spells.
Moon Magic is about Change. Historically the moon represents change; in seasons, tides and even in the moon's phases. The moon is important in mythology; it is said the full moon brings on the change of the werewolf! Wizards choosing the supplementary school of Moon Magic can change themselves into other creatures. That change comes with all the strengths, weaknesses and spells associated with the chosen creature.
The moon school is focused on polymorphing. Polymorph is a way to play Wizard101 where players can use a spell card to transform the caster into another being and swap out their spell deck! You will not only LOOK like a creature, but you will also gain a whole new set of statistics for accuracy, health, pip chance, and more...allowing you to play different roles when grouping with friends. If a duel contains two Life Wizards on one side, one can cast the Draconian polymorph that will boost their damage. If a duel contains two Storm Wizards, one could cast the Gobbler polymorph to change their abilities to suit the duel and the partners in that duel.
Star Magic is similar to Sun Magic -- after all the sun itself is a star -- but where Sun Magic enhances individual spells, Star Magic enhances the Wizard. Wizards that choose to learn the supplementary school of Star Magic can boost themselves over the course of several rounds to raise shields, strengthen spells or improve stats.
The star school is focused around a new type of magic called Auras. Auras are magical energy that surround and protect or strengthen the Wizard. Auras are unique and different from other magic in that they can't be stacked, broken, or dispelled but they will disappear over time. Auras can boost accuracy, damage, resistance, or even convert incoming spells to pips for you. Auras are cast as normal spells and can only have a target of "Self". Auras have a timer on them that is counted in rounds. After this timer is complete the aura is removed. Auras cannot be stacked with other Auras and Casting a subsequent Aura spell will replace the previous one.