[MENTION=42582]pemerton[/MENTION] That's a good description of the idea. I think one of the differences between a "you failed your Stealth check, you get caught with your pants down" DMing approach and a fail forward DMing approach is the focus on the overall goal of the PCs rather than the micro task resolution. The other major difference is the idea of "degrees of success".
To illustrate an example of how I'd handle a party of 5 PCs sneaking past bugbears...
0. Decide whether this is the focus of the adventure (make it a more involved challenge) or it is just one scene in the adventure (make it a single check if 1 PC or group check if all PCs). Let's say it's just a scene involving all the PCs...
1. Make a group Stealth check against a set DC. But do so sequentially, not all at once, so you can respond to the strategy/roll of each player and present interesting choices/complications as they go.
As a side note: it is very possible that some of the PCs may try other tactics besides Stealth, I'm just simplifying for this example.
2. For the first three failed checks introduce a complication, a "fail forward", or the DM makes a "soft move." This would be like the example I gave of a prisoner hearing the PCs and pleading for help. The idea is to give the players a chance to prevent the situation from getting worse; but that if they really blow it or ignore it entirely then they are going to get caught, period.
I choose three because it felt right for the group size and given that there are usually only 1-2 folks trained in Stealth in any D&D party.
3. If four checks are failed, the PCs are flat out caught. Or whatever the failure condition is the DM decides upon; could be the bugbears execute the prisoners, trigger an alarm or trap, or become stealthy themselves and try to ambush the PCs or move the prisoners.
It's very much a mash-up of 4e skill challenge/group checks with Dungeon World. But when I think about what would make for the most satisfying way to resolve the stealth check for DM and players both.
