Summoning Circle is an orb modifier that summons additional orbs of the next orb in your loadout instead of firing a standard orb. It effectively acts as a free duplicator or a pseudo-Multiball applicator: when the circle is placed before an orb, it produces extra instances of that following orb according to the circle's level. Summoning Circle appears in normal runs and interacts with many other game systems that create, modify, or consume orbs.
Summoning Circle summons rather than fires, so summoned orbs do not trigger "When fired" effects. This means single-use orbs that have on-fire triggers will not grant those particular effects when summoned; however, Summoning Circle is useful for preserving single-use orbs (for example Egg or Potion Ball) while still gaining their non-fired benefits and outputs. Summoned orbs also ignore most self-damage or "when fired" penalties, so hazardous orbs that hurt the caster on use become safer when summoned.
Multiple Summoning Circles compound multiplicatively. If a Summoning Circle is followed by another Summoning Circle, the second circle’s output is multiplied by the first. For example, two Level 3 Summoning Circles in series will produce a total of nine copies of the orb that follows the second circle (3 × 3). Because of this multiplicative behavior, chains of Summoning Circles can rapidly produce large numbers of the following orb.
Summoning Circle has a few important practical interactions and caveats:
Placing Summoning Circle at the end of your loadout is weak: it will summon Demon Squirrels (1/2 Squirrel Balls) that have no special "when fired" effects and thus gain few benefits from buffs. End-of-deck Summoning Circles typically yield minimal value.
Summoned Demon Squirrels behave as normal orb instances for most modifiers and relics, but earlier versions had bugs where demon squirrels could be incorrectly buffed; those issues have been addressed in patches.
Visual and rotation effects related to Summoning Circle were refined in later updates to avoid misleading displays when summoned orbs deal no damage or when an enemy is defeated while summoning is mid-process.
Use Summoning Circle to multiply valuable orbs that benefit from quantity (damage-orbs, healing balls that trigger on landing rather than on firing, or orbs whose effects scale with number of instances). Avoid relying on it to trigger on-fire effects and avoid leaving it as the final orb unless you want plain Demon Squirrels.
