The Skill system in playtest has some rough edges, but offers opportunities as well. Table 4-4 (particularly if modified to scale-in the upper right corner values) provides results for any skill, while Table 10-2 can provide matching DCs. Yes, Table 4-4 is listed in silver pieces, but stretch for a moment and consider it to be a measure of progress.
Example Challenge: A journey for 19th level PCs, with various choices of route. It could take 1 day through extreme hazards, or much longer with less. (the only reason I'm using 19th level is that 4-4 isn't scaled quite right all the way through until you pass the level for legendary proficiency).
Table 4-4 lists 1500 for 19th level Legendary, so take that as what they need - the possibility of a single day's journey. If they ask about the easy road (Trivial DC28), a 4-4 Trivial/Failure nets 60, so will take 1500/60= 25 days. If they choose a little risk (Trained/Low DC37), that will get them there in 1500/300=5 days. If they choose higher risk (Expert/High DC 40, 4-4 result of 600), they'll get there in 2.5 days. With greater risk (Master/Severe DC 42, result 1200), they'd have a relatively easy trip left after the first day, and at Legendary, a single day.
Essentially, 10-2 and 4-4 outline four options to scale progress.
Sometimes, expertise in an appropriate skill is required for higher DC/rewards, but sometimes not. The players can 'bid' for an option and get nothing (or little) if they fail. Sometimes, have 1 roll resolve that stage of progress (what DC does it beat - they get that result).
Failure may result in no progress, negative progress, or Trivial/Fail progress. Risk can be represented by Hazards - a Perception check and hit by the Hazard on each PC, appropriate to the risk taken. The GM could require that one character lead, but that half of the party need to make the check at the next lower difficulty.
While this works better with a smoother/wider distribution of 10-2 and population of 4-4, and works better with Hazards scaled so the GM can judge lethality better, the potential is there for a relatively easy system for a GM for resolving any number of challenges creatively, and allowing players space to guide the story of how they do, or don't, succeed this time.
