I’ve long been less than thrilled with the cleric class as far as the mythological/religious aspects are concerned. With a few exceptions, we’ve generally played clerics as non-denominational, so to speak, and pretty much ignored the larger religious implications of the class.
For my Swords & Wizardry White Box game, I’m going to take it a step farther and declare that clerics do not serve the gods at all but are, in fact, mystic warriors somewhat akin to the Jedi Knights in Star Wars. As I’ve already decided that any class can use any weapon in my White Box campaign, this isn’t much of a leap at all.
Clerics must be either Lawful or Chaotic (no Neutral clerics allowed), and Chaotic clerics can only memorize the reversed versions of reversible spells (dark instead of light, cause light wounds instead of cure, etc.). Lawful clerics should not cast the reversed versions lest they risk the path to the dark side. Clerical magic originates from a mystic power with lawful and chaotic sides that constantly battle each other for supremacy.
Clerics attempting to cast spells while wearing plate armor must make a saving throw or their spell will fizzle.
Finally, turning undead is no longer an innate ability. Instead, a Lawful cleric may memorize the spell Turn Undead:
Turn Undead (Command Undead)
Spell Level: C1
Range: 120 ft
Duration: 3d6 minutes
This spell causes undead to turn and flee for the duration of the spell based on the results from Table 20: Turning Undead. Undead unable to flee will cower helplessly, though if the caster attacks any turned undead the spell is broken for all those affected.
Chaotic clerics can command undead successfully affected for the duration of the spell in a manner similar to charm person. Mindless undead will obey without question, but those of greater than 5HD may be able to resist commands contrary to their motivations.
A result of ‘D’ on Table 20 indicates that the target undead are destroyed (if the cleric is Lawful) or that the command period lasts for 24 hours rather than 3d6 minutes (if the cleric is Chaotic).
Qui-Gon Jinn from Episode I is the Jedi who immediately springs to mind here. Clerics in the service to various godlings, demons, and other supernatural powers do exist, but the spells of clerics come from the mystical power that binds the universe together.