Every conjurer can try every spell or effect possible, but their spellcircle provides a kind of thematic descriptor for what effects look like. For instance, a fire elementalist can rip open a hole in space, creating a portal. The effect is described as a single flame seemingly burning a hole into reality. Or for a water elementalist, a certain portion ripples until the destination on the other side can be seen. For arcane bands, energy bands might connect to form a loop that creates the portal.
Under these rules, conjurers are also encouraged to come up with their own spellcircles.