For example, convincing NPCs in dialogue or limiting what people can join you?

Edit
Also, the manual recommends a half-elf cleric. It seems to be specifically a half-elf, not a full one. Can anyone explain why this is? The game says something about being able to "attain maximum levels" but I'm not sure what it exactly means by that. It seems odd to think it would reduce your max level because you're an elf rather than half-elf - and specifically only when you're a cleric.

2nd Edition AD&D (which is the version of D&D this uses) has racial max level caps, which is carried over from AD&D 1st Edition. The Gygaxian explanation for this is that as demihumans get higher in level, they become more concerned with racial concerns rather than adventuring concerns. The game balance excuse is that demihumans have abilities that humans don't from the very beginning, and so to make humans worth playing they get unlimited level advancement while demihumans top out. Similar to how they balanced class abilities with how much experience was required to go up in level, or how they also balanced classes by making their "sweet spots" to be at different levels (fighters start out strong, but gain very little as they go up in level, while wizards start out embarrassingly weak, but as their spells increase in level and variety they become nearly god-like at the upper levels of play).