I'm brewing up an adventure to run next year during our club's 24hr Endurance Challenge that is going to involve the PCs travelling across the country at the beginning of winter with an ancient curse raising the dead and making the countryside darker and more wild.
I want to have some elements for the encounters and the space between that threaten the characters and make everything just a little more challenging and difficult, but how can I work these things into the CR without pushing encounters over the edge of survivability? Things I want to include:
-Sections of land falling away during a battle (10 randomly selected squares at the end of each round)
-Gradually decreasing temperatures
-Staying fed in the wilderness (most settlements they come to are either struggling to feed themselves or destroyed entirely)
-Unnatural darkness (days become low-light)
Well for one option you can make them encounters in their own right. Rather then adding them to the CR of another encounter.
An area of collapsing floors is basically going to be a series of acrobatics checks and reflex saves. You can control the CR by setting the DC for those saves and checks.
Another option is to use creatures of a lower CR and allow the environment to boost the encounter difficulty.
It's hard to give specifics without the party level or composition.
Just to add to your list of effects, you can also use stuff like permanent spell areas: unhallow, desecration, haunted ground etc.
The party level is going to be 5th. Because this is a continues story I'm thinking of granting levels at specific points in the story, mostly to allow for a more dramatic, powerful final boss. If I did implement this, it would be 7th maximum.
As for party composition, I haven't set that yet, but it's going to be 4 players (the easiest number fo balance in my opinion). They can be any base class, but they will have a choice of "item sets" to begin, which are your basic armored class, arcane class, druid/cleric, paladin/cleric, and engineer (any gun-wielding character) with magic items specific to the story.
The basic flow is like this:
Prologue:
-Battle with weak enemies
-No hazards
Act One: 5th level
-Deal with hunger
-Village Defense
Act Two: 6th level
-Getting colder and darker
-Fight increasingly old, powerful undead
-Uncover a traitor/enthralled NPC
Act Three: 7th level
-Constant night
-Deal with warring factions (the king has been overthrown)
-Gather allies and get into the Necropolis (storming it or sneaking in)
-Kill the risen Evil King
The falling away floor might be used for the final boss or for the big encounter in a catacomb in Act Two.
The basic flow is like this:
Prologue:
-Battle with weak enemies
-No hazards
Act One: 5th level
-Deal with hunger
-Village Defense
Act Two: 6th level
-Getting colder and darker
-Fight increasingly old, powerful undead
Well here is a place you can do your environmental stuff. Instead of ramping up the creature CR. Expand on the environment. You can have necrotic clouds, haunted ground, desecration. All of those could be hazardous to the pcs and give buffs to lower level creatures
-Uncover a traitor/enthralled NPC
This could be multiple lower level npcs, perhaps behind the environmental effects above.
Act Three: 7th level
-Constant night
-Deal with warring factions (the king has been overthrown)
-Gather allies and get into the Necropolis (storming it or sneaking in)
-Kill the risen Evil KingThe falling away floor might be used for the final boss or for the big encounter in a catacomb in Act Two.