Looking at D6 Probabilities with the Wild Die,
If you're going to be purely technical about it, it's trivial to figure out the odds of success on a skill check in D&D assuming a set of characters with skills:
Therefore, assuming DC 10, and a bonus of 4, the above returns .75. For a strict translation, therefore, figure out the odds of success for every roll you desire, and simply compare to the chart at the bottom of this page, as a function of how many d6 you anticipate your players will roll.
I, however, would recommend against a literal translation, and instead adapt the mechanics from mouseguard for how challenges work, insofar as every roll matters and failures advance the plot but provide complications. The mouseguard system has already been hacked by the Chatty DM In: Mouseburning it. He notes:
- A task's outcome must be uncertain.
- The task must have significant stakes.
- Don't waste time on tasks and types of activity that have already been resolved (See: let it ride, scene economy).
- Only one Lead, but many helpers (and all share in the stakes)
- Everyone puts their cards on the table, and explains the difficulty and stakes.
- Failure must be interesting and awesome.