Good point. Ambiguity isn't your friend here.
I threw a LAN party or two back in college (faculty sponsored gaming club). We actually got Bawls Energy and some now-defunct PC peripheral companies to sponsor. I designed and hung posters, put an ad in the student paper, did some word-of-mouth adverts in classes.
The first event had what I thought at the time was good turnout of about 30 people. Most people were OK with mainstream LAN multiplayer games of the time, but there is always that one dude who wants to play Hello Kitty Island Adventure or whatever.
In other words, maybe be somewhat specific and name games that are likely to be played.