Since we’re doing skill challenges, here’s this from another thread. I’d love for something like this to be in 5.5.
I really, really loved skill challenges in 4E. They had their flaws but it was a great idea. We found it really hard to come up with interesting consequences to failure that weren't forced combat, death, or lose a healing surge. To us that was boring. So we loosened up the already loose framework, but made it more concrete instead of abstract. Though it could still easily handle abstract and montage scenes well. The DM would set up some montage or action scene and would include obstacles to overcome. There was generally either a separate timer (be done in X rounds or bad thing Y will happen, survive the night, etc) or some consequential fail state, NPC dies, lose some resource, lose favor with NPC, etc.
You rolled as normal, a regular success counted as one and a crit counted as two. A failure counted as one but fumbles weren't used. A failure would either add a new obstacle (usually one success' worth) or would add one to a given obstacle. So you need to climb a wall that takes two successes. Get one success and you're halfway up the wall. Fail and you slide back down and now you need two successes to climb the wall. But it had to make narrative sense. If you're halfway up a wall and you fail the wall doesn't get taller. You slide down. And you populate a skill challenge with a few obstacles that take different skills to overcome and that require differing numbers of successes. You can see an official 4E skill challenge that basically works like this in Dungeon 173. The Colossus of Laarn. Because we'd already converted to doing it this way, switching over to 5E didn't mean abandoning skill challenges.
Two of my favorites were the giant obstacle course and the zombie horde.
We were captured by giants and forced to go through an obstacle course while the giants were cheering, jeering, and throwing boulders. A failure could mean either you fell, slid down a wall, or a giant threw a boulder at you. A PC was halfway up a wall, failed and fell down, failed again so a giant threw a boulder. DEX save or take damage. The player then used the boulder to climb up the wall. There was more to it, of course, but that was the most memorable part.
We were in a town attacked by a zombie horde and had to survive the night. Checks to sneak from building to building without being caught. Checks to scrounge for supplies. Checks to barricade the building we were in. Failures meant time wasted or attracting zombies. The zombie horde would degrade the barricades by one every few hours depending on how many were there. If we were loud more would show up and degrade the barricade faster. Each success made the barricade stronger so it would last longer, but we only had so many resources to work with. We went to the inn and broke up the tables and chairs for wood to barricade the door. One PC was a guild artisan carpenter and handled that while the barbarian pulled larger bits of furniture, barrels, etc in front of the barricade.
It's a loosey-goosey system but it was a lot more fun, dynamic, and interesting than the nailed down skill challenges as written.