My first experience was just last night. I was interested in both how Roll20 worked, and how Roll20 would handle a game like MWP's Marvel Heroic Roleplaying.
MHR requires you to be able to physically track a lot of things – distinctions, plot points, assets, complications, stress and not just die totals, but the *type* of die rolled. I was concerned at how Roll20 would be able to track these sorts of things.
The game opened with my players (taking on the roles of Colossus and Wolverine) travelling to The Raft, a high-security SHIELD prison built for detaining supervillans. There had been a recent break out at The Raft, and Colossus and Wolverine had been called in to tour the facility, check security refits and rebuilds, and generally just use their expertise to make sure everything looked kosher. While there, an alert signal sounded, coming from the detainment cell of the villain known as The Mad Thinker.
[i]This entire scene was essentially a Transition Scene, building up to the action and laying some groundwork for the rest of the story[/i]
The Mad Thinker wanted an audience so he could blather on about some master plan that nobody would be able to stop him from achieving. There was some back and forth (including a comment from Wolverine suggesting that he just carve open the Thinker's head and look for the master plan himself), but it was cut short with a loud crash and several explosions from somewhere above on ground level. Alerts sounded that there was an intruder of some kind of the Landing Deck. Colossus and Wolverine got back to ground level to find The Mad Thinker's Awesome Android tearing the place apart.
[i]This is where we got into using Roll20 in earnest.[/i]
<a href="http://i.imgur.com/tkG5U.png" rel="nofollow">http://i.imgur.com/tkG5U.png</a>
We used the coloured dots to track plot points (which limited us to 5, but the players should be using them up regularly and shouldn't be collecting more than that). The grey square was a drawing I created to store the Scene Distinctions (specific traits about the area that the players can use in their actions), and the orange square was to be used for tracking Assets and Complications that may get created throughout the action. I used the text tool so simply add in the various dice that got collected into my Doom Pool, which is used against the heroes throughout the game. All of these were collected in the top corner, away from the action.
Wolverine's enhanced reflexes allowed him to go first, and as per the Marvel rules, the player could choose anybody to go. He chose Colossus, so Colossus attempted a support action to pick up Wolverine and chuck him at the android. The support was a success, so Wolverine got to use Colossus's strength trait in his attack roll, which came next (and failed miserably). The android reacted and shot poor Wolverine out of the air with its energy blasters. This left the android's turn, where he used his blasters again, targeting both heroes at once – but they either ignored the hit (Colossus) or dodged out of the way (Wolverine). Wolverine's reaction was an extraordinary success, which gave the android the complication of "Flanked". I added this to the orange box on the map.
As per the rules, as I (controlling the android) went last, I chose who got to go first at the beginning of the next round, so I chose myself. The android swung a backhand at Wolverine, but missed so badly that another complication got added – this time, Wolverine's player created the "Off Balance" complication which I added into the orange box. Flanked had been removed already because Wolverine had made use of the complication when dodging the android's punch. Colossus then attacked, and delivered a mighty smash that gave the android d12 physical stress (the highest amount that can be delivered in one hit). Using the health trackers, I added in "d12", which the players could see. As an android, it couldn't take mental or emotional stress, so one more hit with even a measly d4 could take the android out of the action.
We had started late, so it had gotten much later by this point and we needed to stop. I found that Roll20, with some heavy user interaction, can track all the variables required for a game of Marvel Heroic. The drawing tool is a little clunky (I would like it to retain it's colour fill / line settings instead of defaulting back to red), and I found that sometimes the text tool would retain it's settings, sometimes it wouldn't.
Dice tracking works if you are rolling a die pool like this; 1d8+1d10+1d8+1d8, instead of like this; 3d8+1d10. This way you can see which die rolled which result, which is important in a game of Marvel.
Voice and video was a little clunky off the start, and I found that I couldn't seem to select the "allow" button when trying to give it access to my camera. Also, for some reason it disabled my headset, so I needed to go into my control panel and re-enable it. Voice was laggy (probably a 3-5 second delay), to the point that in the future I might just have my players turn off their voice and video and use Skype instead.
The biggest issue, though, was not with Roll20. None of us were that familiar with the system, so we did spend a lot of time looking at the rules.
We'll do this again!