I'm not a very active here in posting stuff but I do read (and play ) a lot. Mostly via RSS feed. I do notice a spam problem on the forum though and I kindly ask to take actions against.
* Spam posts make it to my reader.
* Spam is in profiles of bot accounts (e.g. About Me links)
* Spam is in replies that looks legit (because it's copied from humanz) but riddled with random links.
* Spam is in replies that are edited after a while.
There are various approaches how you could deal with this.
* Mitigate e.g. by making sure that _no_ links can be added until a certain amount of credibility is reached (you _do_ run a ranking system already)
* Weed out "new users" having no posts within months
* Add a moderation queue for new users (you're not really overrun here, eh? :))
* Add a moderation queue for new users if their first posts have links
* Add a game purchase verification (e.g. game key to "link" with a purchase)
* Make use of spammer databases (like StopForumSpam) during the registration (can be checked against local for the privacy concerned)
* Make use of abusive IP databases (like iplists from e.g. Firehol)
Some require action on the system level (hosting), some can be implemented in the software (forum) as plugin.
…just don't add one of those dreaded Captchas - it's 2020 and they are all broken (by design, AI, cheap labour or privacy concerns)