The character may participate in group ritual magic where they combine their power to create effects that far exceed the normal limits of mortal spellcraft. While different traditions of circle magic exist, the most famous are those of the Witches of Rasheman, the Red Wizards of Thay, and the elven High Mages. The spell cast as a circle need not be a ritual spell. For each caster who contributes a spell slot of the original spell to the casting, the group increases the level of the overall spell by +1. Unlike casting the spell using a higher spell clot, there is no limit on the level-dependent variables (damage, number of creatures summoned, etc.). The spell still follows the pattern listed in the spell description for casting at a higher level. So if a spell increases the number of dice rolled for damage per additional level of spell slot, the bonus will be the same. If it increases the number of creatures summoned per ever two spell slot levels higher, it follows that pattern. The circle must have a center, usually the most powerful spellcaster in the group, who harnesses and shapes the power. Depending on the caster's tradition, there may be limits imposed on how many people may participate in the ritual casting.