A Lurker is a player who rarely posts, and when they do post, it's insubstantial, shitposting, or otherwise unhelpful. A good benchmark to see if someone is lurking is if a player has fewer posts than the game's moderator, whose postcount is typically very low.
Types of Lurkers
- Standard Lurker: a player who is clearly in over their head, doesn't have the time to post substantive content, and can barely keep up with the thread. A mod should replace them if it is going to be a chronic problem. This type can be town or scum, since they are lurking for reasons generally unrelated to their alignment.
- Scum Lurker: a scum player who is intentionally posting infrequently in order to avoid suspicion. This person is scum in real life.
- Power Role Lurker: a town power role lurking to avoid getting attention of a nightkill. This is lame. If you're a townie you do far more for your team by posting frequently, making cases, and breadcrumbing your results, than you do by hiding in the shadows.
- Content Lurker: a player who posts frequently, but rarely says anything substantive. This is seen as very scummy, since by posting often a player can dodge accusations of being a lurker, but by saying little they still have the same problems as lurkers: being impossible to determine if they are town or scum.
Players have tried to organize systematic lynches on lurkers, in order to both remove the uncertainty, and to punish lurking so as to encourage active posting in the community. Most players are reluctant, however, because lynching a lurker is seen as a crapshoot.
Still, anecdotally, it seems to be the case that in most games, most of the scum are lurkers. But townies often lurk right with them. And that's terrible.