How can I scale traps in a published adventure for a larger party?

Question

I'm about to start DMing for a group of 7, mostly new to Pathfinder. I myself have not DMed Pathfinder before, and haven't played it recently. We'll be going through the Mummy's Mask adventure path, which (reportedly) has a considerable number of traps.

For normal fights I can always just double the number of enemies, and for bosses I can just throw in some extra mooks and give the boss slightly better stats. But I'm not sure how to scale traps up for a larger party in a balanced way. Should I increase the skill DCs? By how much? Should I increase the damage the traps deal? By how much?

Note that this is an existing, published adventure path, not something I'm designing explicitly for this party. I'd prefer easy solutions, like adjusting numbers, over harder ones like adjusting placement, mechanics, etc.

Answer 1

Depends on the party composition.

Rogues here refers to any character with Trapfinding and ranks in Perception and Disable Device.

1 or more rogues

When there are rogues in your party, traps become basically a rogues-only minigame. The rogue gets to roll Perception and Disable Device, everyone else gets to stand around and wait for the next combat to happen. It doesn't matter if there are 4 or 40 people in the party, since the rogues will be dealing with all the traps.

So if there's only one rogue, don't do anything to the traps. If there are two, you've got two people looking for traps and disarming them. The average result on two d20 rolls is 13.825 so you can just add 3 or 4 to the DCs.

No rogues

When nobody in the party has invested in a way to find or disable traps, you have two ways of going about it:

• Take out all the traps.
• Have them disarm traps by walking into the traps.

If you decide to remove the traps, replace them with some combat encounters and you'll be fine. If you decide to have your party disarm traps with their chests, double the number of traps. Increasing the DC would do nothing since the checks will never be rolled, and doubling the damage risks sending a character from full to 0.

Answer 2

If environment allows, spread the traps over a larger area. For instance, if there is normally a single trap in a 5' wide hallway, instead, increase the size of the hallway, and put two traps side by side.\

Alternatively, a cheesy solution for people who like to play gnome/halfling/short rogues is to put the trigger for the trap higher up, where it will brush the forehead of the party's ork, but would be several feet above the halfling.

All kidding aside, the general answer to large parties is generally more encounters, be they traps or monsters. Scaling up DC's can quickly make rolls unfeasible for low-level players unless they're min/maxing. Similarly, increasing the damage they deal is more likely to severely hinder one character, rather than harm the whole party. Instead, increase the number of encounters to deplete the increase in resources (hp, potions, /day skills, spells, etc.) they have from more party members.

Answer 3

Add guardians to the trap, someone who will attack or harrass players as they try to overcome it.

Suppose the party has to cross a pit: most of the time, they'll do this one-by-one, rather than all fly/leap/teleport to the other side at the same time. Have hidden enemies step out and attack them when they've effectively been split into two smaller and (presumably) weaker parties. Or add archers when they're crossing a rope bridge.

This isn't hard to justify in-game, either. If the trap is a natural occurrence like a pit or a ravine, scavengers would naturally be drawn to it as a source of fresh carrion. If it's a mechanical device, well, someone's got to be there to re-set it, and if the complex is already on alert because there are intruders, trapped locations would be natural places to set a watch. Or there's a spirit cursed to watch over it eternally.

It would be best if players had a chance to detect their presence beforehand: awareness rolls, detection spells, and the like. Electing to use them, of course, is up to the players, but that's standard dungeon faring caution.

Answer 4

Something else to keep in mind is magical means of detecting and disabling traps. A lot of people seem to forget that it is possible to disable and detect traps magically, despite it being potentially costly as well depending on caster level.