This article needs additional citations for verification. (May 2016) (Learn how and when to remove this template message)
The worker formian, the warrior formian, the myrmarch formian, and the queen formian appeared in the second edition for the Planescape setting in the Planes of Law boxed set (1995), and reprinted in Monstrous Compendium Annual Volume Three (1996).
The formian worker, the formian warrior, the formian myrmarch, the formian taskmaster, and the formian queen appeared in the third edition Monster Manual (2000), and the revised 3.5 Monster Manual (2003). The formian worker familiar appeared in Tome and Blood (2001), and in the 3.5 revised Dungeon Master's Guide (2003). The formian armadon, the formian observer, and the formian winged warrior appeared in the third edition Fiend Folio (2003).
Formians first appeared in the first edition Advanced Dungeons and Dragons Monster Manual II, where they were presented as an otherwise ordinary species of intelligent creature from the Prime Material Plane. Full statistics for three main castes of formian were given; the workers (about the size of a large dog), the warriors (the size of a pony) and the myrmarches (the size of a horse). Special types mentioned as being found only inside Formian hive-cities were the male gymarches and the queen.
Formians were later expanded upon by the Planescape campaign setting expansion Planes of Law, in which they were described as one of the primary inhabitants of the plane of Arcadia, the Outer Plane of borderline Lawful Neutral/Lawful Good alignment.
In the Dungeons & Dragons third edition Monster Manual, formians were adapted to the new edition's core rules, in which they are presented as the exemplar species of the Lawful Neutral alignment. In the third edition version of the Manual of the Planes, formians are implicitly described as being the primary inhabitants of both Arcadia and the Lawful Neutral Outer Plane of Mechanus, which is in contrast to the earlier Advanced Dungeons & Dragons Second Edition, where the Modrons were the exemplar Lawful Neutral race and the primary inhabitants of Mechanus.
The Taskmaster caste of Formian is a man sized Formian that lacks the combat abilities of the Warrior but is able to use Dominate Creature as a spell-like ability. It is encountered with a slave creature.
Formians are absolutely bound by the law of their queen. Due to this, all but the highest ranking Taskmasters and Myrmarchs are merely slave-like pawns.
- Gygax, Gary (1983). Monster Manual II. TSR, Inc.
- McComb, Colin and Wolfgang Baur. Planes of Law (TSR, 1995)
- Pickens, Jon, ed. Monstrous Compendium Annual Volume Three (TSR, 1996)
- Williams, Skip; Tweet, Jonathan; Cook, Monte (2000). Monster Manual. Wizards of the Coast.
- Cagle, Eric, Jesse Decker, James Jacobs, Erik Mona, Matt Sernett, Chris Thomasson, and James Wyatt. Fiend Folio (Wizards of the Coast, 2003)