A while back I was arguing that it’s silly that so many people (especially fans of D&D 3.x/Pathfinder) are fine with “monster classes” but that Elf-as-class is somehow absolute madness. I was rebutted by a guy telling me that “Elves aren’t weird aliens. Are you telling me that elves don’t have clerics or thieves?” So here I am, telling you why Elves can’t be clerics (I might go into thieves later). Don’t think this means that I think that race-as-class is the end-all, be-all of D&Desque games; there’s a place at the table for an Elf Cleric, a Dwarf, and a Dragonborn Psionicist. Consider it an exercise in rules-driven world-building.
First, we need to consider why human clerics would exist in the setting. In D&D & Derivatives, Clerics are equipped with abilities to:
Next, let’s look at why a cleric would be important to humans. Humans both fictional and real are always worrying about mortality, which makes someone who cures diseases and heals wounds desirable. On the flipside, there are some human-exclusive curses (AD&D 1e lycanthropes) and undead are mainly spawned from humans (AD&D 2e wraith, older versions of vampires). So there’s a thread of reasoning that suggests that humans generally need clerics around, both to help the living and keep the dead peaceful.
Now let’s look at those clerics abilities in relationship to elves. Are they really that worried about mortality? If they’re long-lived like Tolkienesque and Gygaxian elves then probably not. They got through the first 100 years of their life without any of this magical healing and they can get through the next 500 just as easily (or at least, that’s what the elf thinks when he’s in elf territory). There aren’t any particular curses that necessitate a dedicated curse-remover and the only undead spawned from elves are basically just wyrds so they don’t need undead-hunters.
This also brings up a point about the relationship between gods and mortals. Did human “invent” or “discover” a way to become clerics? Did the gods approach humans and just drop this knowledge into their laps? Why is such magic, which is almost universally helpful to all humans, limited to a select few of them? It almost suggests that humans are actually terrified of the gods; that’s why they have a designated group (clerics) to deal with all that divine stuff while everyone else lives their lives. Therefore there might be another reason for elves to not have clerics, which is that their psychology cannot adapt the necessary way of thinking to access clerical magic. Perhaps humans view the gods as humans imbued with cosmic power, like nobles elevated to the Nth degree, mostly uncaring, rarely benevolent, and often malevolent; entities to be appeased, emulated, and feared. Meanwhile, elves may see the gods as elves who have reached a state of sublime perfection; entities to be emulated, but not appeased or feared.