Clerics specialize in two areas of magical expertise called domains. These domains are selected when first becoming a cleric and cannot be changed unless the first cleric level wasn't taken at level one (in which case you can relevel to change the selection). Domains grant added spells and sometimes a free feat or special ability. Realms of Trinity has none of the Kaedrin or other custom Cleric domains: only the official domains including the ones provided in Storm of Zehir and Mask of the Betrayer expansions. Realms of Trinity also does not grant the extra spells added by Kaedrin to the official domains. Only the spells granted in the original game are added.