3e SRD:Calling Subschool
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The spell fully transports a creature from another plane to the plane the character is on. The spell grants the creature the one-time ability to return to its plane of origin, although the spell may limit the circumstances under which this is possible. Creatures who are called actually die when they are killed; they do not disappear and reform, as do those brought by a summoning spell (see below). The duration of a calling spell is instantaneous, which means that the called creature can't be dispelled.
Spells that call powerful extraplanar creatures are most useful when the conjurer has a magical trap to hold the summoned creature. The simplest type of trap is a magic circle spell (magic circle against chaos, magic circle against evil, etc.). When focused inward, a magic circle spell binds a called creature for a maximum of 24 hours per caster level, provided that the character casts the spell that calls the creature within 1 round of casting the magic circle. However, if the circle laid down in the process of spellcasting is broken, the effect immediately ends. The trapped creature can do nothing that disturbs the circle, directly or indirectly, but other creatures can. If the called creature has spell resistance, it can test the trap once a day. If the character fails to overcome the spell resistance, the creature breaks free, destroying the circle. A creature capable of any form of dimensional travel can simply leave the circle through that means. The character can prevent the creature's extradimensional escape by casting a dimensional anchor spell on it, but the character must cast the spell before the creature acts. If successful, the anchor effect lasts as long as the magic circle does. The creature cannot reach across the magic circle, but its ranged attacks (ranged weapons, spells, magical abilities, etc.) can. The creature can attack any target it can reach with its ranged attacks except for the circle itself.
The character can use a special diagram to make the trap more secure. Drawing the diagram by hand takes 10 minutes and requires a Spellcraft check (DC 20). The DM makes this check secretly. If the check fails, the diagram is ineffective. The character can take 10 when drawing the diagram if the character is under no particular time pressure to complete the task. This also takes 10 full minutes. If time is no factor at all, and the character devotes 3 hours and 20 minutes to the task, the character can take 20. A successful diagram allows the character to cast a dimensional anchor spell on the trap during the round before casting any summoning spell. The anchor holds any called creatures in the diagram for 24 hours per caster level. A creature cannot use its spell resistance against a trap prepared with a diagram, and none of its abilities or attacks can cross the diagram. If the creature tries a Charisma check to break free of the trap, the DC increases by 5. The creature is immediately released if anything disturbs the diagram—even a straw laid across it. However, the creature cannot disturb the diagram itself either directly or indirectly, as noted above.