Spam signups on a game community forum

Earlier attempts had knocked the spam registrations down for a couple of months, then the problem came back each time. This one had to hold for longer than that.

The objective

A game studio's forum had started getting far more spam signups than usual. Other freelancers had cut the numbers before, but the spam came back a few months later every time.

That pattern usually means the fix was a single filter the spam operators eventually worked around, rather than several checks that all have to be passed together.

The client was willing to move to different forum software entirely if that turned out to be the honest answer.

What I did

I looked at how the registrations were actually arriving before changing anything, since a CAPTCHA does nothing against accounts created by hand.

I put several independent checks in place instead of one, so getting past a single check isn't enough to register.

I kept the board on phpBB, because the problem was in the registration path and not in the software itself.

The result

Registration spam dropped, and the community stayed on phpBB rather than moving to different software.