This powerful spell is similar to the 6th-level contingency spell.
Chain contingency allows the caster to designate either two or three spells that will take effect automatically under a specific set of conditions. In other words, when a set of conditions is met, the designated spells are "cast" immediately without the caster's intervention.
Chain contingency must be cast together with the spells it is to trigger. The caster may choose either two spells to occur simultaneously or three spells to occur consecutively, one per round. Spells must be of 8th level or lower. Only the 6th-level contingency spell may not be included. The casting time of 2 turns includes the casting of the spells to be triggered.
Unlike the contingency spell, spells "stored" in chain contingency can affect creatures other than the caster. These instructions must be carefully worded; the spell obeys the letter of its instructions and not the caster's intentions.
In casting chain contingency, the wizard defines the conditions that will trigger the "stored" spells. This definition must be carefully worded, but may be as limiting or general as the caster desires. The caster also states the exact order, target, range, and manner in which the stored spells are to be cast.
The spell has several limitations in triggering its spells. It does not have any powers of discernment; thus, an instruction to "target the highest-level enemy" is not possible. Furthermore, the conditions cannot involve a delay; a spell cannot be ordered to trigger "three turns after I sneeze."
When the named conditions are met, the chain contingency is automatically triggered. If all specifics of casting a spell are not specified (e.g., target or area of effect), the effect is automatically centered on the caster.
Possible triggers might include a fall from a distance greater than the caster's height, the appearance of the first beholder within 30 feet of the caster, or the wizard pointing his finger and pronouncing a specified word.
Only one chain contingency can be placed on the spellcaster at any one time. If a second is cast, the first chain contingency is cancelled. It is possible to have both a contingency and a chain contingency operating at the same time, provided that there is no overlap in the conditions specified for triggering the two spells.
Spells triggered by the chain contingency have a casting time of 1. If the spell is triggered under conditions that are impossible to fulfill, it fails. If one of the spells in a series cannot be fulfilled, the remaining spells in the series are lost. Normal conditions, including line of sight to the target, must be fulfilled. All spells originate from the caster; thus, it is not possible for a caster to teleport and leave behind a series of fireballs to blast his enemies. In this case, the fireballs would either fail or destroy something at the caster's destination.
The material components are (in addition to those of the companion spells) 500 gp worth of quicksilver; a gem of at least 1,000 gp value; an eyelash from an ogre mage, ki-rin, or similar spell-using creature; and an ivory statuette of the wizard (which is not destroyed in the casting of the spell) which must be carried by the spellcaster in order for the chain contingency to perform its function when triggered.
Notes: Uncommon spell (ToM).