Well, I don't want to speak for Stalker0 as to how he intended it or how he does it. In a fast-paced scenario, like say a chase where the PCs have to decide quickly I might well have them all roll simultaneously, one dodges left, the other dodges right, suddenly they find themselves separated. Its the kind of thing that happens. The alchemist drops a flask so he can pull out his wand, the dwarf lights a match, oops!Thanks for the link. I did read it, but I'm afraid I'm still confused. How did you, as the GM, play the bear as simultaneously soothed and intimidated? Or did you decide that one canceled out the other, and if so, how did you decide which one got priority?
I just prompted the players to say what they were doing and had each one roll immediately after declaring. I can see that it might have taken away some of the suspense, but the all-roll-at-once option just seemed like too much work for the GM. Maybe it depends on the nature of the challenge, but it seems like most challenges (especially social challenges) would not be quite so jumbled that everything would have to happen at once.
Particularly if there are knowledge checks involved--the GM would have to remember "Okay, Mary says she's making a knowledge check" while Bill, Bobby, and John all declare their actions; then the GM has to pay attention to whether Mary succeeds or fails at the end of the round and give her appropriate feedback if she makes a success. Then Bill, Bobby, and John can't do anything based on Mary's knowledge check until the next round after that. Have I got that right, for the classic Obsidian system?