<Li> Online magic tricks were designed to function on a computer screen . The computer essentially replaces the magician . Some online magic tricks recreate traditional card tricks and require user participation, while others, like Plato's Cursed Triangle, are based on mathematical, geometrical and / or optical illusions . One such online magic trick, called Esmeralda's Crystal Ball, became a viral phenomenon that fooled so many computer users into believing that their computer had supernatural powers, that Snopes dedicated a page to debunking the trick . </Li> <Li> Mathemagic is a genre of stage magic that combines magic and mathematics . It is commonly used by children's magicians and mentalists . </Li> <Li> Corporate magic or trade show magic uses magic as a communication and sales tool, as opposed to just straightforward entertainment . Corporate magicians may come from a business background and typically present at meetings, conferences and product launches . They run workshops and can sometimes be found at trade shows, where their patter and illusions enhance an entertaining presentation of the products offered by their corporate sponsors . Pioneer performers in this arena include Eddie Tullock and Guy Bavli . </Li> <Li> Gospel magic uses magic to catechize and evangelize . Gospel magic was first used by St. Don Bosco to interest children in 19th - century Turin, Italy to come back to school, to accept assistance and to attend church . </Li>

Where did the term how's tricks come from