I'm setting up a forum for a game guild. I would like users to be able to record and update just three stats, one text and two numbers. The stats should appear in the user's profile but also appear automatically in every post users make, preferably in the section where it has the user's post count and join date. 

Is the RPG addon overkill for that? Can I create custom profile fields instead?

And what are the RPG dice for? I know they roll random numbers, and I know why you need random numbers in an RPG, but what are they used for in a forum?

Thanks!

When you create customized profile fields, there should be an option to display them in profiles and messages.  Check the box for messages so they will appear in posts.  Can modify, check members.

https://help.forumotion.com/t3347-the-rpg-feature