Duodrones were the second simplest type of modron.[2]


Duodrones were block-shaped constructs capable of two tasks at a time. Unlike the more limited monodrones, they were fully capable of communicating in their own language of clicks and whirs.[2][4]


Like all modrons, duodrones had an absolute sense of hierarchy and order, and could not be persuaded to disobey their instructions or betray their purpose in any way.[2]

It was possible, however, for a defective duodrone to go rogue and start acting in its own interests or no longer in accordance with its instructions, sometimes even becoming violent. Such rogues were relentlessly hunted by other modrons, although, unlike their properly operating fellows, they could be reasoned with.[2]


Duodrones were capable of wielding weapons and were competent combatants, capable of performing two attacks at a time. If destroyed, a duodrone disintegrated completely into dust and a monodrone was instantly upgraded into a duodrone to fill its position.[2]


Duodrones could communicate with other duodrones and with monodrones and tridrones. They were incapable of comprehending more advanced modrons.[2]

In modron society, duodrones were responsible for supervising units of monodrones. They were always created as the result of upgraded monodrones to take the place of destroyed units.[2]


Sometime in the late 1480s DR, a duodrone that was part of a group of modrons that were stranded in the Underdark was held prisoner in the Wormwrithings. The duodrone had been captured by Karazikar, who hoped to learn information about the Maze Engine.[4]




  1. 1.0 1.1 David "Zeb" Cook (1994). Planescape Campaign Setting, Monstrous Supplement. (TSR, Inc), pp. 16–19. 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 2.11 Wizards RPG Team (2014). Monster Manual 5th edition. (Wizards of the Coast), pp. 224–225. ISBN 978-0786965614.
  3. Gary Gygax (August 1983). Monster Manual II 1st edition. (TSR, Inc), p. 87. ISBN 0-88038-031-4.
  4. 4.0 4.1 4.2 Christopher Perkins, Adam Lee, Richard Whitters (September 1, 2015). Out of the Abyss. In Jeremy Crawford ed. (Wizards of the Coast), p. 177. ISBN 978-0-7869-6581-6.