On AG2, users can rate games that they play, but they can't rate threads. I think that (possibly for the AG3 equivalent of 1 AP), users could rate threads. I think that rating threads would help people to figure out which threads are really worth being checked out. Also, people could use ratings as a search filter if AG3 has a forum search and potentially earn an achievement. On a side note, I think it would also be a good idea if users could "follow" threads. There are threads I have been interested in keeping an eye on, but occasionally not found so I think that following these threads could save people a lot of time.
