Bigby's interposing hand was an evocation spell that created a hand of force to block a targeted opponent from approaching. Priests who could cast this spell named it for their deity—Selûne's interposing hand, for example. To Zakharan mages, always reluctant to acknowledge ajami names and accomplishments, the spell was known simply as interposing hand, and counted among the spells of the universal province.
This spell was one of the Bigby's hand family of spells. It created a hand about the size of an ogre or about 10 ft (3 m) tall with a finger span about the same as the height (earlier versions could be even larger) that was placed between the caster and a chosen opponent to gain partial cover from a ranged attack. The hand also slowed the approach of an opponent to half their normal speed if they weighed 2,000 lb (910 kg) or less, or at least made it difficult to advance if the opponent was stronger than the hand.
All versions of this spell relied on the caster's senses to detect and locate the target, the hand did not have senses of its own, but once a target was designated the hand would remain interposed regardless of movement by the caster or the opponent and was unfazed by invisibility, darkness, polymorphing, or other means of concealment or disguise. The hand was difficult to injure, but could be destroyed by inflicting damage equivalent to what it would take to kill the caster in prime condition. The hand could be disintegrated or dispelled if it failed to resist such spells.
Range and duration varied widely over the history of this spell. For the earliest versions, a wizard that was just able to learn this spell could maintain the hand for nine minutes and cast it 90 ft (27 m) indoors/90 yd (82 m) outdoors. Later version lasted between 45 seconds and a minute but the reach was extended from 120 ft (37 m) to 190 ft (58 m) at a minimum.
In addition to verbal and somatic components, this spell required a glove of some sort that varied as reported by different recordings of the spell. The earliest version could use any glove. A later version specified a "soft" glove and the next version made it a focus instead of a component, so it wasn't consumed in the casting. After the Second Sundering this was refined to a snakeskin glove and additionally required an eggshell (because many types of hand options were combined into one spell).
- Mike Mearls, Jeremy Crawford (2014). Player's Handbook 5th edition. (Wizards of the Coast), pp. 211, 218. ISBN 978-0-7869-6560-1.
- Jeremy Crawford, James Wyatt, Keith Baker (November 2019). Eberron: Rising from the Last War. (Wizards of the Coast), p. 56. ISBN 978-0-7869-6692-9.
- Jonathan Tweet, Monte Cook, Skip Williams (July 2003). Player's Handbook v.3.5. (Wizards of the Coast), p. 204. ISBN 0-7869-2886-7.
- Hal Maclean (May 2007). “Seven Saintly Domains”. In Erik Mona ed. Dragon #355 (Paizo Publishing, LLC), p. 26.
- David "Zeb" Cook (August 1989). Player's Handbook (2nd edition). (TSR, Inc.), pp. 165–166. ISBN 0-88038-716-5.
- David "Zeb" Cook (April 1995). Player's Handbook 2nd edition (revised). (TSR, Inc.), p. 210. ISBN 0-7869-0329-5.
- Mark Middleton et al (November 1996). Wizard's Spell Compendium Volume One. (TSR, Inc), pp. 83–84. ISBN 978-0786904365.
- Richard Baker (1996). Player's Option: Spells & Magic. (TSR, Inc), p. 184. ISBN 0-7869-0394-5.
- Dale Donovan (January 1998). Cult of the Dragon. (TSR, Inc), p. 125. ISBN 0-7869-0709-6.
- Sam Witt (January 1994). The Complete Sha'ir's Handbook. (TSR, Inc), pp. 124–125. ISBN 978-1560768289.
- Gary Gygax (1978). Players Handbook 1st edition. (TSR, Inc.), p. 79. ISBN 0-9356-9601-6.
- Adam Lee, Christopher Perkins (September 17, 2019). Baldur's Gate: Descent into Avernus. (Wizards of the Coast), p. 77. ISBN 0786966769.
- Jeff Grubb and Ed Greenwood (1990). Forgotten Realms Adventures. (TSR, Inc), p. 153. ISBN 0-8803-8828-5.