This would be a decent thing to have a news section (or at least a button) In-game, either on main menu or wherever you would like it to be.

As I've seen in most games, whenever devs make some event for the game they put some short description on prizes and short detail about the event then if they have any forum they put a link to the actual thread.

So the newcomers to Toribash who don't know where and what forum is can check out the news and get some idea off it. Then if they're interested they'll click on the link which will lead them to the actual thread to learn some more on how the event works.

(To be kept in mind that the Events are just to be game related. Not some kinda weirdo music events with shitty prizes).