When a PC decides that he want to add a subclass of Cleric, the DM can use Divine Intervention.
Theres 10% change of this event happening.
The DM has to roll a 1d10 every night that the player sleeps.
If the DM hits 1, the PC will recieve Divine Intervention, if not, nothing happends.
If Divine Intervention happends, the PC goes to another realm (while asleep), where he communicates with a God, depending on the Cleric Domain.
Since there are 14 Domains, the DM has to roll 1d20, to see wich one the PC while be communicating with (optional):
1- Arcana Domain - Selûne
2- Death Domain - Nerull
3- Forge Domain - Moradin
4- Grave Domain - Kelemvor
5- Knowledge Domain - Ogma
6- Life Domain - Lathander
7- Light Domain - Pelor
8- Nature Domain - Silvanus
9- Order Domain - Tyr
10- Peace Domain - Eldath
11- Tempest Domain - Auril
12- Trickery Domain - Tymora
13- Twilight Domain - Yondalla
14- War Domain - Tempus
Level
Cantrip
Casting Time
Special
Range/Area
Self
Components
None
Duration
Until Dispelled
School
Divination
Attack/Save
None
Damage/Effect