Secundi were the most powerful of hierarch modrons. They were second in power only to Primus itself.[4]


Secundi appeared like very thin and tall humanoids, with long faces and deep-set eyes.[2]


If forced into combat, secundi used a combination of innate abilities, spells, fists, and psionics.[2]


Like all hierarch modrons, secundi had the innate ability to duplicate the effects of clairaudience, clairvoyance, command, dimension door, teleport without error, and wall of force spells at will.[5] Secundi were able to cast arcane spells as well as divine spells from the Law, Protection and War domains. Secundi were immune to all effects that influenced the mind, all psionic-based attacks and had a resistance to acid, cold and fire.[2]


There were only four secundi in modron society.[4] They could communicate with other secundi and relayed their orders to tertians under their command, but reported directly to Primus itself. Each secundus was a viceroy in charge of one of the four quarters of their realm in Mechanus. They could communicate telepathically with anyone in a 420‑mile (680‑kilometer) radius.[2][4]

Secundi were always created as the result of a tertian being promoted to take the place of a killed or further promoted secundus. If Primus died, one of the secundi was promoted and took its place as the new Primus.[6]


Secundi were able to communicate telepathically with any sentient creature within 420 mi (680 km) and could see in darkvision up to 60 ft (18 m).[2]


Around −346 DR, Netherese archmage and explorer Lady Polaris came upon Mechanus and the modrons. She summoned several decatons to her home to guard her treasures, but was stymied as they kept disappearing after several days. She suspected that a secundus was behind the disappearances as a form of extraction, and later had more sucess with the pentadrones she focused on next.[7]

After Orcus killed Primus and triggered an unexpected Great Modron March, he left the Energy Pool in Regulus to search for the Wand of Orcus, leaving the way open for a secundus to be promoted into the new Primus. However, prolonged contact with the Pool caused Orcus's evil influence to taint a fraction of the modrons. One tainted secundus disputed the ascension of any one of the other three and demanded that the successor be chosen by a rite of challenge: the successor would be the one who slew the largest number of chaotic creatures.[8]

The challenged secundus proceeded to Limbo and killed vast numbers of slaadi, but the tainted one ordered an army of modrons to invade Bytopia and destroy entire settlements of gnome petitioners. Once his treachery was discovered, in particular the breaking of the rules that involved the secundus not slaying creatures with his own hands and not destroying creatures diametrically opposed to pure law, the two remaining secundi denied him victory in the challenge. The enraged tainted secundus left Mechanus, taking almost a million modrons with him, and settled a modron colony in Acheron. This schism crippled the modron race and paved the way for a formian invasion of Mechanus.[8]



The Great Modron March
Evil at Baldur's Gate #3


  1. 1.0 1.1 David "Zeb" Cook (1994). Planescape Campaign Setting, Monstrous Supplement. Edited by David Wise. (TSR, Inc), pp. 16–20. ISBN 978-1560768340.
  2. 2.00 2.01 2.02 2.03 2.04 2.05 2.06 2.07 2.08 2.09 2.10 Mark Jindra (2001-09-21). The Modrons (Zipped PDF). Wizards of the Coast. pp. 17–18. Archived from the original on 2016-11-01. Retrieved on 2018-09-09.
  3. Gary Gygax (August 1983). Monster Manual II 1st edition. (TSR, Inc), p. 91. ISBN 0-88038-031-4.
  4. 4.0 4.1 4.2 4.3 Mark Jindra (2001-09-21). The Modrons (Zipped PDF). Wizards of the Coast. p. 2. Archived from the original on 2016-11-01. Retrieved on 2018-09-09.
  5. Monte Cook, Colin McComb (1997-10-28). The Great Modron March. Edited by Michele Carter. (TSR, Inc.), p. 126. ISBN 0-7869-0648-0.
  6. Mark Jindra (2001-09-21). The Modrons (Zipped PDF). Wizards of the Coast. pp. 2–3. Archived from the original on 2016-11-01. Retrieved on 2018-09-09.
  7. slade (1996). How the Mighty Are Fallen. (TSR, Inc), pp. 3, 31. ISBN 0-7869-0537-9.
  8. 8.0 8.1 Ken Marable (April 2007). “Return of the Modrons”. In Erik Mona ed. Dragon #354 (Paizo Publishing, LLC), p. 36.


Mechanical Beings of Inherent Order
Base Modrons: MonodroneDuodroneTridroneQuadronePentadrone
Hierarch Modrons: DecatonNonatonOctonSeptonHextonQuintonQuartonTertianSecundus
The One and the Prime: Primus
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