From time to time, I see people describe either campaigns or systems (not necessarily at the same time) as 'pulp' or 'pulpy'.
At first I thought it referred to pulp fiction (the literature, not the film!), which, one one hand, seems to be defined as being low quality and having 'lurid, exploitative, and sensational' content, and on the hand tends to be associated with such great classics as Mark Twain, Howard Phillips Lovecraft, Isaac Asimov, Ray Bradbury, Agatha Christie, Arthur C. Clarke, and Philip K. Dick.
But I have to conclude that the word has to mean something else than those two things, as none of the campaign and systems described by it seem to exhibit any of the two groups of characteristics: they seemed neither any more lurid, nor sensationalist, nor exploitative than 'usual' campaigns and systems, and they didn't seem to exhibit anything that would make me think 'Oh, this is Twain/Howard/Bradbury/etc.!' upon reading or playing them. (There's also the complication that the writing styles of those authors are quite different: Bradbury is unlike Twain is unlike Lovecraft is unlike Clarke.)
For example, Cypher- and FATE-based games are typically described as innately pulpy due to the game engine they use, but I wouldn't say that Numenéra, Transhumanity's Fate, Mecha vs. Kaiju, Tianxia, Crisp Line, or even the Core itself shares much, if anything, with Lovecraft, Bradbury or Twain; they also don't seem particularly more lurid or exploitative compared to RPGs in general. Similarly, I once joined a campaign that was pitched as pulpy, curious how that should feel, and after many years of play I'd say that it felt more like a cross between Dishonoured and X-Com (the two computer games) than with the writings of pulp authors as either described or experienced.
Thus I want to ask: if 'pulpy RPGs' are not characterised by any of the above, then by what are they characterised? What sets them apart from other styles or similar groupings of RPGs? Is there a difference between the things that define a pulpy system (rules and mechanics) and a pulpy campaign (plot, drama etc.)?