As the name implied, the Ruby Rods owned by the avatars and aspects looked like a big solid ruby that was formed into the shape of a rod. Those owned by avatars or powerful aspects were worth more than a million gp in material value alone, while weak aspects' were worth less, meaning upwards from 50,000 gp. However, the original owned by the Asmodeus' main body was made from a shard of evil and merely tipped with a ruby.
These four-foot (1.2-meter) rods had an opaline tip looking like a clawed fist clutching a skull and a jagged bottom that looked like the rod was actually part of something bigger and snapped off from that bigger something. They were covered with good deities' and celestials' names, all spelled in reverse and sullied with black blood.
These rods gave off a soft red light. Upon shooting energy blasts, the rods gave off beams of light in every direction.
One of the easiest ways to use a Ruby Rod of Asmodeus in combat was to use it as a bludgeon. Used like that, a Ruby Rod worked like a +6 unholy greatclub; however, versions that worked like a +2 unholy greatclub or +1 morningstar owned by weak aspects were also known. Whatever the strength of the Ruby Rod when used as a bludgeon, they did not damage the victim in physical ways but also in magical ways, as though affecting the body with a inflict critical wounds, or inflict light wounds in the +1 morningstar version. Having Asmodeus' permission to wield a Ruby Rod allowed a person to wield it without getting hurt.
As mentioned above, Ruby Rods could shoot energy beams. To be more precise, there were three versions—a 150-foot (45-meter) beam of electricity, a beam of acid that was the same length, or a 75-foot (23-meters) cone of intense cold. The abilities could be used as often as he wanted by Asmodeus but only once per day by other people.
The Ruby Rod had three protective abilities. One forced people to bow down before the wielder, thereby making it impossible for them to attack the wielder. The second one was about creating a wall of force around the wielder as well as a 50-foot (15-meter) radius antimagic field that magically repaired the wielder, first by making away with detrimental enchantment effects, then with mundane detriments like lost body parts that grow back, diseases, and poison-induced effects, and at last with a full recovery of the wielder's physical health and magical energy. The last ability could be activated intentionally but did so automatically whenever the wielder fell victim to an enchantment effect. The abilities could be used as often as he wanted by Asmodeus, but only once per day by other people. Third, it could protect the wielder from spells by absorbing them into the rod. However, this use of the rod was not unlimited.
The original Ruby Rod of Asmodeus was created by Asmodeus from the shard of evil, which he broke off from the bottom of the Abyss and killed He Who Was, his superior at the time. This was during the Dawn War. The crafting of the rod required the shard of evil and a huge ruby soaked in the blood of a thousand mortals, Tiamat's drool for its acidic qualities for quenching, and the tears from 777 angels. Given that it required Tiamat's drool, the time frame during which the rod was crafted was between Tiamat's birth, or Io's death at the hands of Erek-Hus, and He Who Was' death at the hand of Asmodeus who used the Ruby Rod for the deed.
According to the play The Trial of Asmodeus, which was allegedly based on facts, Asmodeus was obliged to always carry the Ruby Rod of Asmodeus by Primus. The rod would act both as a symbol for him and his devils' right to forge pacts with mortals and as a punishment device for all devils that do not respect the strictures of their bargains.
Sometimes, Asmodeus gave a Ruby Rod to somebody else. However, it was never known if what he gave was a replica or the genuine thing.
- Monte Cook (Oct 2002). Book of Vile Darkness. (Wizards of the Coast), p. 121. ISBN 0-7869-0672-3.
- Robin D. Laws, Robert J. Schwalb (December 2006). Fiendish Codex II: Tyrants of the Nine Hells. Edited by Chris Thomasson, Gary Sarli, Penny Williams. (Wizards of the Coast), p. 156. ISBN 978-0-7869-3940-4.
- Monte Cook (Oct 2002). Book of Vile Darkness. (Wizards of the Coast), pp. 121–122. ISBN 0-7869-0672-3.
- Robert Wiese (2007-02-16). Fiendish Aspects II (Zipped PDF). Wizards of the Coast. p. 23. Archived from the original on 2016-11-01. Retrieved on 2018-09-08.
- Mike Mearls, Brian R. James, Steve Townshend (July 2010). Demonomicon. Edited by Scott Fitzgerald Gray. (Wizards of the Coast), p. 9. ISBN 978-0786954926.
- Mike Donais, Skaff Elias, Rob Heinsoo, and Jonathan Tweet (October 2003). Miniatures Handbook. (Wizards of the Coast), p. 48. ISBN 0-7869-3281-3.
- Robert Wiese (2007-02-16). Fiendish Aspects II (Zipped PDF). Wizards of the Coast. Archived from the original on 2016-11-01. Retrieved on 2018-09-08.
- Chris Pramas (November 1999). Guide to Hell. Edited by Kim Mohan. (TSR, Inc.), p. 51. ISBN 978-0786914319.
- Rob Heinsoo, et al. (April 2010). The Plane Above. Edited by Cal Moore, et al. (Wizards of the Coast), pp. 65–66. ISBN 978-07869-5392-9.
- Mike Mearls, Stephen Schubert, James Wyatt (June 2008). Monster Manual 4th edition. (Wizards of the Coast), p. 74. ISBN 978-0-7869-4852-9.
- Mike Mearls, Jeremy Crawford (May 29, 2018). Mordenkainen's Tome of Foes. Edited by Kim Mohan, Michele Carter. (Wizards of the Coast), pp. 9–10. ISBN 978-0786966240.