Horologium

Wondrous item, legendary

This complex astrological clock accurately reproduces the motions of all the heavenly spheres and celestial bodies, running ceaselessly despite its lack of motor or mainspring. The horologium can serve as a spellcasting focus for all divination spells, and when used as such you may call upon one or more benefits.

• Once per day when you use the horologium to cast a divination spell you may do so without expending a spell slot.

• Once per day when you use the horologium to cast a divination spell, the spell takes effect as if it were cast using a spell slot two levels higher than the level at which you cast it.

• When you use the horologium to cast divination, augury, or another divination spell that has a percentage chance of providing a random reading when cast multiple times, the spell fails instead of providing a random reading.

• Once per day when you use the horologium to cast conjure celestial or another spell that summons a being from the higher planes the spell’s duration doubles.

• While consulting the horologium you have advantage on all ability checks related to astronomy and astrology.

You may apply one or more of the horologium’s benefits to the same spell. The only way to destroy the horologium is to use it to cast divination and ask how to destroy the horologium. If you do so the horologium, crumbles into a mound of rust, iron filings, and corroded metal.