James just put up a post about D&D, specifically Clerics. I played obsessively for a few years in the 1980's and occasionally after that. Clerics as a category don't quite work. The game requires some healing and rescue, so that got stuffed in the bin. The original formats were somewhat medieval, and not only was the church important in that context, but many knight and paladin types were tied in pretty closely to particular saints, shrines, or causes. Another thread in the creation was in battling against monsters that had a spiritual or unearthly component, so you had to have someone for that as well. It was a mixed grill that didn't entire fit together. A typical party was a fighter, a magician, a thief, and a cleric. We like fours. It feels balanced. As one went further, there were specialty and mixed categories of the four. In retrospect, these were an unnecessary aid to creative character design. No need for a specialty category of illusionist, ranger, or assassain. You could just be that in your basic category. I suppose you could propose as you went to the DM that you wanted to specialise at something and were willing to give up some advantage in some aspect in order to gain it in another.
I never played a cleric, and didn't see the advantage. A good NPC to have along, maybe.