I ran two of these yesterday, back-to-back, and totally improv. The group was returning from the dungeon but were in the vicinity of bandits, so they decided to try looking for the bandits, and I had to come up with something better than "OK, keep making Perception checks until you find them." Party members were level 2-4.
The first challenge was to figure out the location of the bandit camp. It started as a mental challenge, but at the end of segment 2 they flushed a runner, and had to chase him down, making segment 3 a physical challenge. Then, they had a social challenge to interrogate the guy (Intimidate primary). They got a partial success when the dwarven fighter decided to try for an extra intimidation bonus by cutting off the guy's leg. I ruled this an application of Going for Broke -- it didn't work and the guy passed out, but by then they had enough info to count it a partial success (I gave out a piece of info with each success).
I had printouts of the PDF but didn't show it to any of the players. I just explained it as I went, revealing options (Bold Recovery and Primary Skill) as they became needed. Everybody got the core concept right away.
At first people were trying to use whatever their best skills were but eventually they were trying wacky things. I think it clicked when I explicitly told them that the DC was always 19, and that the only real way they could get ahead was to do creative stuff in the hopes of impressing me enough to give +2 bonuses. Giving out the bonuses is something that I need to get better at, but by the end of the challenge I think it was working well. The party wizard is the type of player who is always trying crazy stuff (and usually it doesn't matter, which frustrates him) but for the challenge he kept getting +2 bonuses, so that was good. Also, I think a really great way to simulate "Aid Another" is through those bonuses -- for example, the warlord and the rogue got a "good cop/bad cop" routine going that used their skills well (Diplomacy/Insight and Bluff/Intimidate/Streetwise) and got them +2 bonuses to both actions on certain segments.
Overall I felt it went really well, and solved most of my issues with the
RAW system. The only real problem is the dwarf fighter, who has few skills, low mental scores, and tends to roll poorly. He was more engaged during the Obsidian challenge than the
RAW challenges, because he knew he couldn't hose the party by generating a failure, but it was still a little frustrating for him. I think that may be
4e's fault, really, for giving the fighter only 3 skill picks.
-- 77IM