All of our members are 18 or older (mostly older). Our main rule is "Don't be an asshat." It's worked well so far.
We play plenty of shooters and MMOs, as well as the occasional round of Rocket League and similar games.
Expect a mid-to-high skill level at most games. We don't like playing poorly and don't mind putting in the hours to get better.
Most of our members have been around for at least 4 or 5 years. It's not unheard of to meet with fellow members in real life.