August. Let’s not talke about RPGaDay. Let us rather embark on a journey into K-Space and through a selection of the endless possibilities for campaigns.
Sardaukar
Official Dune RPGs all fail me simply because they are not designed to enable playing as Sardaukar. But exactly that is the one campaign I would want to (need to) do first. A Sardaukar campaign. A campaign meant to let people experience first hand, viscerally (in the sense of their enemies’ viscera, probably) why that fighting force was so feared, how it came to be one of the pillars on which the structure of the Corrino Imperium rested.
After that, any number of other campaigns might be set up – all now with that undercurrent of knowing, knowing that it simply will not do to upset the Padisha-Emperor.
(Alternatively, a second Sardaukar campaign taking a look at their decline and finally their defeat by the Fremen might make for a follow-on all the more tragic based on that first campaign.)
(And of course all of this requires a long, hard look at the system to be used, if not created.)