A standard mission is meant to run for approx. 3 main challenges. I feel that going significantly over this number will lead to strong unbalancing, as the finite number of “trick” the characters have (stress, armor use etc.) is balanced against this recommendation.
Our starting mission (heavily inspired by the BoB actual play) consisted of the following stages:
- Getting into storm drains under a castle without being spotted by undead patrols (simple obstacle - 1 stress spent for support action)
- Navigating the storm drain/sewers under the castle and avoiding Rotters
(More complex obstacle/stage - 1 stress spent for flashback and 1 spent in a group action)
- Distracting the Horror and rotters in the castle yard and then sneaking into the keep
(2 stress spent to push roll for diversion, 2 stress spent on group action to sneak in)
- Bypassing or defeating Cinder Guard in the keeps 2nd floor
(Good planning by players and incredible lucky rolls - they defeated the level 3 threat with only 4 stress for the heavy to n push himself and reduce a consequence)
- Rescuing the commander from the ongoing transformation overseen by the Doctor
(6 stress across the players for pushes, avoiding consequences and group actions)
- Fleeing the keep while poison gas released by the Doctor fills the room (6 stress for resisting corruption and a group action with 4 rolls of 1-3)
So overall no character died, but they burned through all armor uses and had a total of 23 stress among 4 player characters (two character went above 6 stress in the final challenge).
You could say that such a close call is very rewarding (and it was - the players liked that it wasn’t a walk in the park), but they were very very lucky with their dice. With “average” rolls the pretty sure all would have died …
Did I use too many challenges? Even if you dismiss the first minor challenge of getting into the storm drain, the players faced 5 challenges (2 of which facing level 3 opponents). They rolled very well (except for the last group action), but still made it barely out.
I don’t like cutting down the number of challenges, as this doesn’t feel like it would suite the fiction in this case. If I always run such linger missions, should I grant all characters extra stress boxes for free (e.g. +2)?