My understanding is that Roger was never really "into" role playing games, with dice or without. I believe that he played a couple of sessions with Erick to see how the game worked, but I've never seen Zelazny offer any real opinions about RPGs.
I have an anecdote to contradict that.
For years I ran community radio stations, and probably the coolest thing I got to do was interview Melinda Snodgrass. She's an unsung hero in Science Fiction media. Snodgrass was the chief Story Editor on the third season of
Star Trek: The Next Generation. She was brought on after writing the second season episode "Measure of a Man" (the one where they put Data on trial), which she sold as a spec script on the suggestion of her friend George R. R. Martin. Martin was writing scripts for the Ron Perlman starring TV show
Beauty and the Best at the time, and encouraged his friend Snodgrass into TV writing.
Melinda Snodgrass knew George R. R. Martin through their share New Mexico role-playing game group, which also included Roger Zelazny. They met weekly for a few years (I have no idea when, I'm guessing late 70s or mid 80s?) and played GURPS. She said they played other systems too, but she didn't remember exactly what, but most of the time it was GURPS. I asked, "Why GURPS?" and she gave me a hand-waving explanation about how they (or at least she) only used the rules when they didn't know what to do. She said they played in a pirate setting, an ancient roman setting, and a pulp setting that would eventually inform George R. R. Martin's
Wildcards series of short stories.
If Roger Zelazny can be in a weekly GURPS game, he was definitely a big role-playing geek.
//Panjumanju