Virtual tabletop (VTT) applications are great. I remember playing some great campaigns over OpenRPG back in the day, and run a campaign over MapTools for a bit. That said, VTTs also have their limitations, especially when it comes to trying to emulate the in-person RPG experience.
These days Roll20 seems to be the VTT I hear about the most, although MapTools and Fantasy Grounds also have a cult following. (And there are numerous other VTT programs.) My most recent experience is with Roll20, so I'm going to talk about that the most.
VTTs have come a long way since my OpenRPG days. The rise of integrated VoIP and video has done wonders in bringing online play closer to the in-person experience. Many VTTs support 3D dice that look like they roll, and some support custom skins to reinforce the game's feel.
In particular recently I've been looking at what it would take to run a Saga Machine game (Against the Dark Yogi, Shadows Over Sol) in Roll20, and the experience isn't as smooth as I would like. Both these games by default use decks of poker cards in their core mechanic. And while Roll20 provides a deck of poker cards by default in campaigns, its event handling with cards is far less developed than its dice-based event handling.
Technically I can see why. Cards are a more complicated programming challenge than dice. They're also less frequently used in RPGs than dice are. It makes sense then to spend less programming fleshing out their use. It is, however, unfortunate.
Since cards are not handled as well as I would like, I decided then to look at the alternative dice-based mechanic provided in Against the Dark Yogi: Campaign Options. This has better supported event handling in Roll20, but it is still somewhat lackluster.
The real difficulty with this mechanic is when to take the primary die and when to add the two dice. Roll20 supports roll commands for "take highest," "take lowest" or "exploding dice," but it doesn't handle "add matching pairs" very well.
Well... That's not quite true. Roll20 has an option where if one pays for a "Mentor Account" then one gets access to a programmatic API. So with some monthly payments, programming knowledge and time banging out the right scripts, the Saga Machine dice mechanic can be made to work. The card mechanic might be made to work, too, but it would take some even more complicated scripting, and even then I'm not entirely sure about it.
As more and more tabletop games move online, VTT support is increasingly important. That said, in the future I hope to investigate some of the options that would make Saga Machine VTT support more smooth.