Hunting in Urbinia
Skill challenges are groups of skill checks with a common goal in mind that the entire party (or applicable members) participate in. Play will proceed in initiative order. Skill challenges will primarily be used to pass the time in place of more drawn out individual skill checks.
The number of passing checks needed in the challenge will be dependent on the amount of time available/needed to complete the task (anywhere from five to ten, usually eight). There will also be a certain number of failures allowed, usually three. As long as the number of passes is reached before the number of failures is reached, the challenge succeeds. No one can use the same skill twice in a row and no one can use the same skill immediately after the person before them. The target number will usually be 12 + the average party level.
For example, the party must navigate through the Underland. Rather than having one person roll five Survival checks, the GM declares this to be a skill challenge needing five checks (or three failures) and initiative is rolled. The ranger declares she will roll Survival to determine the right direction to travel (pass). The barbarian, who was getting ready to say she will roll Survival to avoid the ravenous Wheatstalkers, switches to saying that she will roll knowledge (nature) to avoid places where the ravenous Wheatstalkers would be expected to be (pass). The cleric says she will roll Perception to watch out for pit traps (pass). The ranger cannot roll Survival since she did last time, so she decides to roll Heal to watch the party for signs of dehydration during the trek (pass). The barbarian says she will make an Athletics check to break down a stuck door at the end of their trek (fail). Since the barbarian failed, it is now the cleric's turn. She says that she will roll knowledge (religion) to give a secret sign to a nearby farmworker who is a member of her religion and get him to tell them about another nearby hidden entrance (pass).
While passing a skill challenge is great, failure does not end the game, nor does it deny XP (although it may halve it). What it does do is temporarily give some kind of advantage to the enemies. This may be a surprise round, it may be that the heroes have to fight to get their quest item instead of protect it, it might be that the BBEG gets away.
There is another way the skill challenge can be run, and this is when the party rolls to reach a sum total. The general rules are the same, but instead of rolling against a target number, the party is trying to get enough skill rolls to hit a target number (150, for example). These will be used when success can be assumed and the question becomes how quickly it can be achieved. Each roll will represent a discrete block of time and reaching the target number earlier will mean that less time has been spent.