Below is a list of the gods that are supported by the game either in base or through remnants of Early Access content, as well as their respective 5e domains that I believe their clergy ought to be restricted to. In the case of domains unavailable in-game, I've substituted appropriate mods that could be given support to complete the gods' divine portfolios further below. Certain gods that are the patrons of specific races are also given racial restriction suggestions.
Available gods to choose from in the base game and their respective domains
- Selûne: Knowledge, Life, Twilight
- Bahamut: Life, War - Should be changed to only be able to be selected by metallic dragonborn (brass, bronze, copper, gold, silver).
- Tempus: War
- Tyr: Order, War
- Helm: Life, Light, Twilight
- Ilmater: Life, Twilight
- Mystra: Arcana, Knowledge
- Oghma: Knowledge
- Kelemvor: Death, Grave
- Moradin: Knowledge, Forge - Should be changed to only be able to be selected by gold/shield dwarves.
- Corellon Larethian: Arcana, Life, Light, War - Should be changed to only be able to be selected by high elves.
- Garl Glittergold: Trickery - Should be changed to only be able to be selected by rock gnomes.*
- Yondalla: Life, Twilight - Should be changed to only be able to be selected by halflings.
- Lolth: Trickery, War - Already restricted away from Seldarine drow, but ought to be restricted to Lolth-sworn drow in general entirely.
- Laduger: Arcana, Death - Already only available to be selected by duargar, but could be changed to be the only deity they are able to select akin to how Lolth-sworn drow can only select Lolth.
- Gruumsh: Tempest, War - Should be changed to only be able to be selected by half-orcs.
- Tiamat: Trickery - Should be changed to only be able to be selected by chromatic dragonborn (black, blue, green, red, white).
- Eilistraee: Light, Nature, Life
- Lathander: Life, Light
- Talos: Tempest
- Tymora: Trickery
- Mielikki: Nature
- Bhaal: Death
- Bane: Order, War
- Myrkul: Death
- Shar (otherwise only available to Shadowheart): Death, Trickery
As she is not a goddess, Vlaakith doesn't have any domains assigned to her. In fact, githyanki as a people have no religion whatsoever other than their worship of Vlaakith due to the way their society is organized, and even githyanki knights' single-minded devotion to Vlaakith - while compared to that of paladins in 2e material which granted them class abilities that are mirrored from the paladin's special abilities - doesn't even get them any actual spells. For the sake of the game's mechanics, if outright preventing githyanki from selecting cleric is an impossibility, then I would suggest assigning her the War domain, given the githyanki's war-like culture. Though as she is not an actual divine being, the optimal and ideal solution would be to find a way to remove githyanki clerics from selection outright, as any githyanki that does not worship Vlaakith is sentenced to be destroyed by her and Vlaakith should be unable to grant powers to her faithful as a goddess would be able to.
Missing Domains
The Arcana, Forge, Grave, Order and Twilight domains are missing from the portfolios of base game gods. This mod ought to provide all of the missing domains (as well as Peace, which has no associated god amongst the base game deities) with 20th-level support, but it hasn't been maintained in just under two years. The Death domain having since been added to the game further makes that part of the mod obsolete. A modified version that removes the Death domain and, at the discretion of the creator, also removes the Blood and Moon domains that are homebrew material from Critical Role and have no associated deities in Forgotten Realms (Peace could also be optionally disabled due to a complete lack of selectable gods that use it as a domain), and is made to work with patch 8 and this suggested mod would be needed.
*Forest gnomes' patron deity of Baervan Wildwanderer (Nature) and deep gnomes' patron deity of Callarduran Smoothhands (Knowledge, Nature) are not included in the game. This may go beyond the scope of the mod request, but I would suggest adding these gods to the list to complete the selection of gods relative to available races in the base game.