About 15 years ago or so (so, no, not Halting State) I read a science fiction book about a virtual reality MMO.
The protagonist in the story was female. There's a bit in there also where she was leading a new player orientation in game and referred to another woman who was, well, well endowed as having “great tracts of land”. (Just a phrase that sticks in my mind.)
The core of the plot dealt with the title to some virtual estate that was won in a joust(?) and was being used for nefarious purposes prior to her claim to it. The former owners were going to great measures (both in game and out of game) to reclaim the title.
One part of it involved a cross platform chase – her primary game was a fantasy dungeon crawl style... but in part of it they moved to other games on the system including a war reenactment game and a mecha game.
As I said, I remember reading this about 15 years ago (between 1995 and 2000) and it was likely newly published in that time frame (likely not from before '90).