[quote=@Vilageidiotx]
I've been wanting to do a Roman RP, but it is difficult to get them off the ground. I have been thinking of making an RP set in late antiquity based on a world where a unified Roman Empire survives long enough to face Islam, but i don't feel confident that there are enough period interested in that time period to justify it. 
[/quote]

Well, the Eastern Roman Empire fought Islam didn't it? Came off pretty bad if I recall. 

In fact, didn't we send the Crusaders over, because the Byzantine Emperor was like "yo, we're losing, and when we lose, then you Catholics are gonna get a face full of Islam"? 

But yeah, the idea of a Western Roman Empire, or indeed, a totally Unified Empire (No Byzantium) would be interesting. I did a lot of research into the how the western Empire fell; poorly managed multiculturalism was a big factor, if memory serves. Also the whole pagan vs Christianity thing went down like a boat on fire full of orphans. 

Your best bet, to make it simple, but also credible, is to inject a highly competent Western Emperor in 300-400 A.D who managed to reverse Rome's fortunes, stabilize the frontiers and the flagging economy, and who through political means reunited Rome with Constantinople. That way you haven't got to read through tonnes of history books to grasp the finite details of what went wrong, and why. 

EDIT: Unless that's what you want to do; may take you a while though. In any case, I'll keep an eye on things and see how they develop.