I ran a skill challenge mixed with combat yesterday.
The setup:
The party is in a swamp where some vampire has performed a ritual centered on an obelisk. 4 sacrifices are bound to the obelisk, and their blood is powering the ritual. Their souls are being tormented and slowly ... "thinned" to fuel the ritual. The blood is entirely symbolic and it is regenerated as part of the ritual. Their bodies are beyond the turning point to death.
The ritual's actual effect is that it protects the Vampire and others of his kind from the effects of the sun _and_ it makes creating new undeads considerably easier (and cheaper).
The PCs have overpowered the Vampires and other undeads guarding the Obelisk, and they found a description of the ritual. Unfortunately, aside from some notes scribbled on the sides, the script is unreadable for them, written in Abyssal.
But the ritual book also contains a few traditional rituals, among them Comprehend Languages. None of the players are Ritual Casters, but the Warlord is a multiclassed Wizard, so he is well trained in Arcana. He determines he could try to bring down the ritual, even if it poses some risks - the victims might be turned into undeads if he is not careful enough, and the rituals energy will discharge possibly uncontrolled in the area. To improve his chances, he first wants to try performing the Comprehend Languages ritual. In this context, I decided to make it a kind of "Micro Skill Challenge". he could try an Arcana check multiple times, but each time he failed, he'd need to spend a healing surge to try again, and 2 failures would be enough to make it impossible to try again.
The reward - aside from being able to read the detailed description was a "reliable" reroll as part of the actual challenge. "Reliable" means he could decide to reroll a check, and if the reroll fails, too, he can try again for his next check, until he finally succeeds with it.
The actual skill challenge required 8 successes before 4 failures. The first 2 checks represented actually the major part of the ritual. Characters could use either Arcana or Religion for the ritual itself, and secondary skills were:
- Religion for gaining a +2 bonus to the next check. (No success or failure)
- Endurance. A player character succeeding this check could try to "attract" one of the energy strikes from the breaking ritual. A succesful check indicates that they manage to endure the pain long enough to absorb the entire blast, though this dealt moderate damage (1d8+5 necrotic and radiant damage).
The Warlord felt the presence of undeads in the area approaching the Obelisk and warned his comrades. On the third "round" of the ritual, actual combat started, as some Swamp Ghouls (basically normal Ghouls with Swamp Walk, people that drowned in the swamp) arrived. The Ranger and the Fighter moved to defend the Warlord. The first batch of Ghuls was quickly dispatched thanks to the Ranger's Bows.
This started the final stage of the encounter. Anyone performing the counter-ritual could attempt a Arcana (or Religion) Check as either a minor (Hard DC) or as a standard action (Moderate DC). A succesful check also meant that the PC could direct one of the energy spikes, making an Intelligence +3 attack vs Reflex, dealing 1d8+INT radiant and necrotic damage.
Endurance and Religion could be used as mentioned before, requiring a minor action each.
More and more undead arrived, including some tougher ones (the first batch was merely minions), and the PCs had an additional constraint - The Arcana Check could only be made within a certain distance of the Obelisk, and the Ghouls all have grabbing attacks... Their goal was to drag the ritual caster off the area. Each round they made no arcana check, they would gain one failure.
There were basically three possibly end results:
Success: The ritual ends and the victims die naturally, the undead in the immediate area are destroyed.
Failure: The ritual does not end, OR the victims rise as undead. This result could only be achieved if some Endurance check succeeded. Basically, every energy spike not directed by the caster or absorbed by his comrades would hit the victims. Every 2 successes would also free one victim.
Failure (Total): Ritual does not end, the victims rise as undead.
The PCs succeeded with 8 successes and 2 failures. The reroll saved them... The Warlord was grabbed multiple times, but only once did a Ghoul actually manage to drag him off. (But not far enough to get out yet.) Thankfully, he wasn't grabbed by the non-Minions, that could have ended badly...