Game was canceled due to illness or conflicts for three players. So, as a side discussion...
My Merchant Prince game last Tuesday was really interesting. The PCs are in a Dragonborn city, trying to deal with diplomatic niceties so that they can pass northwards to their actual destination. The problem is that this city is at war with another one to the north, and as members of the Ridolfi family the PCs are (like it or not) official representatives of their empire. Blow off the local Imperator and it may have diplomatic repurcussions, even if the Imperator is only 7 years old and his senior minister hates your country.
That game began with the PCs messing with a local gang boss, the dragonborn who runs the illegal and unofficial gladiatorial battles. They'd just been caught ganking the guards outside his club down in the bad section of town, a labyrinthine sandbar covered with hovels. I had the session planned - giant fight!
Not so much.
Instead, the group decided to run. Actually, they decided to split up and then run, with the elven rogue and half-elven ranger accompanying Sarah Ridolfi (iron chef bbq's half-elven bard) to get her to safety, and the other three (a warforged cleric, a dragonborn paladin and Blood Jester's genasi fighter) escaping separately. The first group had all the stealth and streetwise skills, and escaped the ghetto with no problem whatsoever -- four consecutive successes in a stealth-and-streetwise skill challenge.
The other group, though? Those three had a max streetwise skill of +6, and an even worse stealth skill.
So off they go, blundering into the night through winding paths and around hovels. Almost immediately they're at 1 success and 2 failures for the "getting out without getting lost and caught" skill challenge. I can still have my fight! I describe how they find themselves almost trapped by a small inlet, and then accidentally double back on the building they were trying to escape from. But then the paladin pulls off three consecutive streetwise checks, the last one exactly spot on the target number, to successfully escape. It was beautiful... and I got to handle the rest of the session (politics, diplomacy and investigation) on the fly.
We ended the game with the group deciding to harass the gang boss by taking out his lieutenants. If they systematically dismantle his protection, they figure he's going to get scared and get sloppy. First person to blink loses, as certain members of the local government are looking for a sign of weakness to take him down, just as other members of the government are looking for an excuse to catch the PCs at something. Our heroes decided to set an ambush.
As a result, I've given the group homework. Next game they are responsible for designing the encounter. They can provide the map, the set-up, and the location; they decide where the ambush takes place and what it looks like, including any interesting terrain. I'll provide the bad guys. It can be in an arena gladitorial combat or in the sewers, or any fantastical place in between. I'm looking forward to seeing what they come up with to give themselves an advantage. In return, I get to provide interesting bad guys for them to take on. This sort of "thrust encounter design back to the players" thing is unusual for me, but I'm finding it exciting.