When I was a child/teenager, I remember reading a series about someone/someones playing some sort of augmented reality games. The players all wore glasses of some sort so they could see the game world, but underneath everything was a prop or robot. So while the glasses the player wore showed the players monsters, in reality they were actually robots walking around, and instead of a razor sharp sword, it would be a sword style object.
I can't remember if the books were in a series or just in the same game world, but there was more then one. It would have been before 2000. The games they played were like live action roleplaying, it would take several days. I remember in one book they went to some desert, maybe navada or somewhere like that in the US to compete in some event.
It's been bugging me trying to think of the series, so any help would be appreciated.