Another concept we'll play with as we explore skill challenges in greater depth is the idea of having currencies -- something that the players can spend as they work their way through a challenge.  

In one sense, successes themselves are the primary currency in a skill challenge  -- the players work (make skill checks) to earn enough to buy the success they need.  In addition, a failed check in some challenges cost a healing surge, for example. We're going to stretch those rules a little, and present some challenges that include options for spending surges in new ways -- and that introduce some other currencies to spend, where we can. 

For example, lets imagine a skill challenge to pry open a massive, giant sized door in a Cyclopean ruin. We might set the DC for an athletics check to pry the door at high, and allow for few other skills to help).  It would probably take a character with a high strenght and good athletics several round to get the four successes necessary to open the door. 

But we could consider some options for faster/better performance:

A Character trained in athletics might be able to:

- spend a healing surge to turn a Hard DC into a Medium DC (or, to add +5 to a roll)
- spend a healing surge to turn one success on a check into two
- spend a healing surge to reroll a skill check in the challenge

Now, I doubt we would want to make all of those available in the same skill challenge -- each will have it's own flavor, and we may decide that we prefer one to the other, but it's important to see what we're doing here -- we're giving the player a choice. An option -- more than just roll the die and see how you do, now the player has the option to pay an important resource (a healing surge) to buy a success on the check.

Odds are it would not be worth it to spend a surge if the players are trying to pry open the door and time is not short, but if they're trying to pry open the door in combat because it's their only means of escape, the choice to spend a healing surge to get that door open sooner could be very tempting -- even necessary for the party's survivial.  

These options should be very situational. It is probably not appropriate to allow a PC trained in athletics to spend a healing surge for a reroll on just any athletics check he makes, for example -- keep the option tied to the specific skill challenge.