Question: How many spells Per turn?

Hi, was there laying a game with some friends where one of them played as the wizard and he would basically just”cycle” through his smells one of the others then got the magic staff or what it’s called that allows you to always have one spell on hand and they just cycled through the spells as long as they met the requirements. Anyone know the rules behind this and if it legal to cast legit 5 spells in a row?