Traps

In Secrets of Xendix, pg.88, Eberron presented rules for making Encounter Traps that are presented more like monsters than the traditional traps already presented in 3.5. However, given the current Pathfinder rules, the mechanics for creating Encounter Traps is redundant, provided that one takes into account the following pre-existing rules from Pathfinder. So long as these rules are observed, an Encounter Trap can be readily recreated through the use of combining multiple traps (even the same exact trap multiple times) to provide a higher CR.

1. Designing the Trap

Every trap has both a trigger and an effect. These two parts of a trap are usually in the same square or in adjacent squares, but they do not have to be. So long as the reach or range of the effect covers the desired area, a trigger square(s) can be placed as far away from the effect square(s) as desired. Often, Encounter traps will also have a bypass option, located in the same square as the trigger(s) or somewhere outside of the affected area. The exact locations of the trigger and effect squares, and the bypass square, if any, should be predetermined and set when creating the trap.

2. Detection of a Trap

In the Pathfinder Corebook, pg. 416, the detection of a trap refers specifically to the detection of the trigger square(s). If successful, the character learns that the square(s) have a trap trigger in them and the means that it activates (location, touch, proximity, etc). This means that the Trap Spotter rogue talent, and other similar qualities, would only allow secret GM Perception rolls as the character passes within 10 feet of a trigger square(s). The character would not know the location of the effect square(s) unless he beats the Perception DC by 5 or more, and even then, he would only learn the effect square(s) that are directly related to that specific trigger square(s).

And remember, a trap that attacks an unaware character is resolving against the Flat-Foot Armor Class.

3. Disabling of a Trap

As per the Pathfinder Corebook, pg. 94, by default, disabling a trap, whether it is a regular trap or a complex trap, requires 2d4 rounds of full round actions. Certain qualities can reduce this time requirement. The Disable Device check is made in secret by the GM and if the check fails by 5 or more, that trap triggers. While it is probable that the disabling of the trap occurs outside of combat with the rest of the team holding still, if it is needed to know exactly when the trap triggers, I recommend first determining the amount of time it takes and randomly determine that the trap triggers either immediately upon the attempt or just as the attempt is finishing (50/50).

What is not explicitly mentioned, but assumed in that the person disabling the trap needs to be physically manipulating the trap. If the trigger is a location or touch trigger, this can be done at the trigger square(s). If the trigger is a proximity, sound or visual, it has to be done at the effect square(s). Based on the exact nature of the trigger, like in the case of magical detection, getting to effect square(s) or manipulating them from afar without triggering the trap is part of the challenge.

4. Disabling of Multiple Traps

When designing a trap that is comprised of multiple smaller traps, the final EL is determined using the individual trap's CR, just like determining an encounter. However, disabling a single trap does not disable the entire Encounter Trap as a whole unless the traps are dependent upon each other. While chaining multiple traps to the same trigger is possible, disabling the trigger negates the entire Encounter Trap. As such, when designing Encounter Traps, be careful about using the same trigger. And be aware that the trigger of one trap can be the activation of another.

5. Bypassing a Trap

As per the Pathfinder Corebook, pg. 95, bypassing a trap through the use of Disable Device requires beating the Disable Device DC by 10 or more. Without making this higher DC, the trap is still armed and while the original character can pass safely, subsequent characters are still in danger. As the Disable Device check is also made in secret, this means that a trap that is safe for the disabling character and is not for his companions would not be known until someone else attempts the trigger event.

However, on pg. 418, an optional bypass element is available for traps as well. Encounter traps are often used at key junction points inside of buildings or underground in order to filter out those that are supposed to pass from those that are not. Thus, I would recommend making regular use of the Bypass option when designing Encounter Traps. It is important note that bypassing a trap is not the same knowing how to avoid the trigger event. A priest that knows which squares to walk through down a corridor is still in just as much danger if he takes a misstep as the adventurers that come through later.

Bypass options are also located in their own squares, usually at the same square(s) as the trigger or otherwise outside of the potential affected area. Magical traps that rely on proximity, sound or visual triggers often have their own method of bypassing the Encounter Trap, based on what stimuli is the exception for the trigger.

6. The Effects of the Trap

As characters get to higher levels, the types of traps that would actually challenge them need to get exponentially more inventive. In order to help keep up with the curve, remember these key aspects about traps.

6a. The Never Miss Quality

Some traps are designed with the Never Miss quality, meaning that the effect of the trap applies to everyone equally regardless of Armor Class or Reflex save. These are often poison traps (so Fortitude saves still apply) or traps where the structure itself is changing, like a crushing wall trap.

6b. The Onset Quality

Having a trap's effect wait for a set period of time after it is triggered gives time for the party to be distracted by other things (combat, looting bodies, healing). This can easily allow a surprise round or attacking flat-foot Armor Class.

6c. Non-Damaging Magical Effects

When making magical traps, it is easy to get into the habit of damage, damage and more damage. This is a poor strategy. Instead, use critical debuffing techniques, such as Bestow Curse, Dimensional Lock, Dimensional Anchor, Dispel Magic, Mind Fog, and Slow. Effects that also good terrain control work equally well.

6d. Non-Damaging Non-Magical Effects

Traps do not have to do damage in order to be threat to the party. Alerting creatures further inside the building or lair is a good example. Closing and locking a critical door is another. In both of these examples, the impediment to the party isn't measured in hit points, Armor Class or saving throws, but is equally dangerous. A closed door can be made of either wood, stone or metal. An alarm can cause multiple encounters to join as one larger encounter.

6e. Relocation and Separation

One quality not explicitly mentioned in the Pathfinder Corebook, but is again assumed as valid under the laws of physics, is the forceful relocation and separation of the party. Having a trap cause two halves of a floor to drop into two different chutes to two different areas or simply having a metal wall separating two halves of a room is a good way to threaten the party without affecting hit points, Armor Class or saving throws.