Dark Dreams (1985) improves on The Last Grimoire. We get back to the weird and idiosyncratic.

For instance, an 8-page piece detailing an example street gang of Arduin called the Black Rabbit Gang, including their turf and bios for all 15 of the juvenile delinquents. Or the introduction of Rogue magick, which is a set of utility spells that any non-magic user character can have access to given the proper criminal background (Arduin always used an ability-score derived magic points system in addition to the traditional D&D memorization/level mechanic, so all characters have a mana pool, even if most can’t access it for  anything). I imagine most folks hated this, but I kind of love it. There is also lots of stuff on alchemy, different sorts of spider silk and a pretty hefty system for running gladiatorial bouts.

I think the thing I like most about Arduin is the lack of pretense on Hargrave’s part. You really get the impression that all of this stuff is coming directly out of his game sessions, willy nilly, as they happen. He and his players were coming up with such odd stuff constantly, then filtering it through a thoughtful process of codifying it for outsiders, but never fell into the trap of worrying about whether it seemed cool enough or even made any kind of sense. Hargrave just rolled with it and put it out there. I suppose that is a sort of naivety or guilelessness, but I like it.