|Title(s)||Keeper of Secrets under the Mountain, the Silent Keeper, the Mountain Shield|
|Home plane||Concordant Domain of the Outlands|
|Alignment||Neutral (LN tendencies)|
|Portfolio||Mining, mountain dwarves, underground exploration|
|Domains||Earth, Knowledge, Protection (also Cavern, Craft, Dwarf, and Metal in Forgotten Realms)|
In many campaign settings for the Dungeons & Dragons role-playing game, Dumathoin (DOO-muh-THOE-in) is the patron of mountain dwarves, and the dwarf deity of mining and underground exploration. He is also the protector of the dwarven dead. His holy symbol is a cut, faceted gem inside of a mountain.
Dumathoin was first detailed in Roger E. Moore's article "The Dwarven Point of View," in Dragon #58 (TSR, 1982). In Dragon #92 (December 1984), Gary Gygax indicated this as one of the deities legal for the Greyhawk setting. He also appeared in the original Unearthed Arcana (1985).
Dumathoin was first detailed as part of the dwarven pantheon in the Forgotten Realms in Dwarves Deep (1990). He was detailed in the book Monster Mythology (1992), including details about his priesthood. His role in the cosmology of the Planescape campaign setting was described in On Hallowed Ground (1996). He received a very detailed description for his role in the Forgotten Realms in Demihuman Deities (1998).
Dumathoin is described as a gigantic male dwarf with a barrel chest. His hair and beard are sculpted gray stone, and his skin is earth-brown in color. His eyes are silvery flame. He carries a two-handed mattock made from solidified magma.
As his title the Silent Keeper implies, Dumathoin never speaks. He communicates with gestures and the occasional grunt or sigh.
In many campaign settings, the dwarven pantheon of gods consists of the leader Moradin, as well as Abbathor, Berronar Truesilver, Clanggedin Silverbeard, Dugmaren Brightmantle, Dumathoin, Muamman Duathal, and Vergadain. Other dwarven gods may be present in different campaign settings.
Dumathoin is a rival of his brother Abbathor, who hoped to become patron of the mountain dwarves before Dumathoin was given that position by Moradin. Abbathor is also infuriated that Dumathoin hides precious metals and gems where he cannot find them.
The Silent Keeper is allied with Calladuran Smoothhands, Cyrrollalee, Grumbar, Flandal Steelskin, Segojan Earthcaller, Sehanine Moonbow, Skoraeus Stonebones, Urogalan, and every dwarf god except for Abbathor and Laduguer. He is friendly with other nondwarven gods of mines and smiths. He names among his foes Abbathor, Kiaransali, Laduguer, Urdlen, and the gods of the goblins, kobolds, orcs, and evil giants. His relationship with the illithid god Ilsensine, whose divine realm his realm overlaps, is nonhostile, though the exact relationship between the two gods is a mystery. Their respective worshippers are hostile to one another, however.
Dumathoin shares the Dwarven Mountain on the Outlands with Dugmaren and Vergadain. Dumathoin dwells in the deepest level of the realm, called Deepshaft Hall. Deepshaft Hall is dark, icy, and stale with the smell of the dwarves who mine it. The roughly cut mineshafts twist confusingly. The petitioners who dwell in Deepshaft Hall use special gems, called soul gems, as tools for gaining union with the realm and their deity. There is an illicit trade of these gems to shadow demons. Dumathoin's domain intertwines in places with the realm of Ilsensine.
Dumathoin does not object to tunneling, mining, or gathering the treasures of the Oerth, but he frowns on clumsy or haphazard mining. Dumathoin's worshipers are encouraged to seek out the hidden gifts that Dumathoin watches over and to enhance their natural beauty and the beauty of the mines from which they are taken. Dumathoin does not encourage greed, as he says that true beauty is found in discovery and crafting, not hoarding. Dumathoin teaches that tombs are to be kept inviolate and well tended. He deeply opposes the undead, particularly dwarven undead. Secrets are considered precious by the faithful of Dumathoin.
As previously noted, Dumathoin is the patron of mountain dwarves. He was presumedly worshipped by those mountain dwarves who lived in the Stark Mounds, where the Mines of Dumathoin are found.
Dumathoin's clerics dress in brown leather. Their heads are bare, but they wear earth-brown cloaks and robes. They never trim their hair or beards. Their favored weapon is either the warhammer or military pick. They seek to uncover the treasures of the earth without marring the natural beauty of the tunnels and mines and without succumbing to greed. They supervise mines, ensuring they are safe and secure from monsters. They also help with subterranean agriculture. They are morticians and protectors of tombs.
Dumathoin's holy days are on the nights of the new moons and the days following and preceding those nights. This day-night-day sequence is known to Dumathoin's faithful as the Deepstone Triad, for they teach that the moons hide themselves beneath the Oerth during these times.
Sacrifices of gems and jewels are made to the Keeper of Secrets Under the Mountain during the time of the Deepstone Triad. Precious stones are ground to powder and mixed with herbs and fungi to be used as fertilizer for subterranean flora.
The dwarven dead are cleaned and stone tokens are woven into their beards representing the deceased, their clans, and the symbol of Dumathoin. The corpses are dressed in armor regardless of their living profession, and a song is composed honoring the dwarf's living deeds. This song is not sung out loud, as the silent Dumathoin does not require or approve of unnecessary noise.
Myths and legends
According to dwarven myth, Dumathoin hides the treasures of the earth until dwarves are worthy of finding them. He lays veins of precious minerals where he feels his followers will benefit from them the most, and guides the worthy to them. Some dwarven myths claim that the veins of precious metals beneath the earth are hairs of Dumathoin's beard.
- Moore, Roger E. "The Dwarven Point of View." Dragon #58 (TSR, 1982)
- Gygax, Gary (December 1984). "From the Sorcerer's Scroll: Clerics live by other rules". Dragon (Lake Geneva WI: TSR) (92): 22.]
- Gygax, Gary. Unearthed Arcana (TSR, 1985)
- Greenwood, Ed. Dwarves Deep (TSR, 1990)
- Sargent, Carl. Monster Mythology (TSR, 1992)
- McComb, Colin. On Hallowed Ground (TSR, 1996)
- Boyd, Eric L. Demihuman Deities (TSR, 1998)
- Boyd, Eric L, and Erik Mona. Faiths and Pantheons (Wizards of the Coast, 2002).
- Noonan, David. Complete Divine (Wizards of the Coast, 2004)
- Conforti, Steven, ed. Living Greyhawk Official Listing of Deities for Use in the Campaign, version 2.0. Renton, WA: Wizards of the Coast, 2005. Available online: 
- Olsen, John. "Worth its weight in gold." Dragon #109. Lake Geneva, WI: TSR, 1986.
- Living Greyhawk Journal no. 3 - "Gods of Oerth"