On SS13 there is a gamemode named "traitor" where a few (or one) member(s) of the crew are chosen as a traitor, they need to complete a set of objectives like assassinate a person or steal a jetpack and get off the station alive, by leaving on the emergency shuttle. This goal can be achieved anyway possible, whether blowing up half the station try to break into EVA or gassing the whole ship. So it is loaded with tons of paranoia and fun, even when there isn't a traitor game running.
Oh, i've played a ton of DarkRP too.