There is already a total count of up- and downvotes, but please never add karma to Lemmy. We don’t want to deal with karma farmers and minimal karma requirements to post. I don’t care about the moderation issues because karma brought more harm than good. Please never add that bloody dreadful thing to Lemmy. I already saw a bunch of people supporting adding karma to Lemmy, which will turn Lemmy into a cheap Reddit clone and karma-farming hell. Please, never add karma to Lemmy. I beg you. No more karma hell.
It prevent things like mass-downvoting from counting much towards karma AFAIK, but that’s more/less the idea of karma. The exact way it was calculated had nothing to do with people trying to game it. Minimums to post in communities did mean spamming elsewhere just to be able to post where you wanted though and the economic worth of “trustworthy accounts” made karma a karma an issue. Upvotes - downvotes still functions for the latter purpose. If people decide the fediverse is worth scamming, then farming will be a thing. Right now, its a fairly small niche space with an average user who is more internet-savvy than most mainstream social media users, so its probably not worth the effort of trying to scam here yet…