Hazards are some of the most common challenges in Pathfinder, apart from monsters, and the most common hazards are traps. Most of the hazards in the Pathfinder Playtest are traps, but there are also environmental hazards like mold and quicksand, or even haunts. Rather than have different rules for each type of hazard, in the playtest, hazards all have a unified format, though how you might find them and deal with them can be quite different.
Noticing a Hazard
Most hazards can be noticed using Perception, although simple or obvious magical hazards are easily noticeable via detect magic and similar magic. Some hazards are so easy to locate that you might notice them even if you aren't even searching. Other hazards might be created or hidden in a particularly devious way and require a certain proficiency rank to notice them before it's too late, even if you're searching. (The rogue's Trap Finder feat improves this even further in the case of traps, but any character with legendary Perception can find any Perception-based hazard—not just rogues!) These harder-to-locate hazards don't appear until higher levels, since it's incredibly unlikely to encounter a level 1 trap created by a legendary crafter, though that doesn't mean all high-level hazards are hard to notice. For instance, the most dangerous example hazard below, the Armageddon Orb, is trivial for almost anyone to notice.
Disabling a Hazard
The skill needed to disable a hazard varies. Traps are usually disabled via Thievery, environmental hazards via Nature or Survival, and haunts via Occultism or Religion, though there are exceptions in every category. Many hazards require a certain number of successes before they are fully disabled, and a critical success typically counts as two successes. A critical failure means you've accidentally triggered the hazard! Many physical hazards can also be destroyed by brute force. In many cases, breaking the trigger mechanism might set the trap off prematurely, which you might be able to do from a safe distance. We felt it was really important to make dealing with hazards a more narrative experience without taking lots of extra time or requiring the GM to make up details on the spot, and so every skill that can be used to disable a hazard is listed in the stat block, along with a description of the how a PC would use that skill to do so.
Simple or Complex?
Out of everything in the playtest, hazards may be the one component for which you can get the best preview right now. How? Starfinder. We had already created an early framework for hazards by the time Starfinder came around, so when I was asked to create a framework for Starfinder's traps, I adapted what we had for the Pathfinder Playtest, and the rest of the Starfinder Core Rulebook team liked what they saw. We've refined the playtest's system since then, which means that we have two main types of hazards: simple hazards that trigger, take their reaction, and are then done, and complex hazards that roll into initiative and shift the game into encounter mode until the PCs deal with them (or at least escape).
Let's take a look at several sample hazards!
Hidden Pit Hazard 0
Stealth DC 16
Description A trapdoor covers a 10-foot-square pit that is 20 feet deep.
Disable Thievery DC 12 to remove the trapdoor, making the trap no longer hidden (Perception DC 0 to notice)
AC 10, TAC 7; Fort +1, Ref +1
Hardness 4 (trapdoor); Immunities critical hits, object immunities, precision damage
Trigger A creature walks onto the trapdoor.
Effect The triggering creature falls in and takes falling damage (typically 10 bludgeoning damage). That creature can use the Grab Edge reaction to avoid falling.
Reset The trap still causes falling damage if anyone falls in, but the trapdoor must be reset manually for the trap to become hidden again.
Ah, the pit, the most basic of all simple traps. Anybody can find a hidden pit, even if they aren't searching for it, because the Stealth DC doesn't require a proficiency rank. If someone walks onto the trapdoor, the pit uses its reaction to open up, and the triggering creature might fall. The Disable entry explains how a character can pop the trapdoor off and make the pit obvious to all. Still might want to be careful crossing, though!
Armageddon Orb Hazard 23
Stealth DC 10 or detect magic
Description A roiling red orb, forged from a drop of Rovagug's blood, rains fire from the sky when a specified condition is met.
Disable Thievery DC 51 (legendary) to imbue thieves' tools with aspects representing Asmodeus and Sarenrae and use them to drain away the orb's power over 10 minutes, taking 5 fire damage each round during that time
[[R]] Burn It All (divine, evocation, fire)
Trigger A special condition set by the trap's creator, typically on the event of her death.
Effect Fire rains from the sky in a 100-mile radius, dealing 10d6 fire damage to creatures and objects in the area (Reflex DC 46 for half damage, or no damage on a critical success). Any creature reduced to 0 Hit Points in this way dies instantly. This is not enough damage to completely burn away a forest or level a mountain or city, but it typically kills most creatures in the area.
This one was pure, over-the-top fun to write. What would a level 23 hazard even look like? This one is really obvious but incredibly difficult to disable. The effect's damage is not even remotely a threat to high-level PCs—but if they care about any NPCs in the region, chances are they're not going to want to set this thing off!
Bloodthirsty Urge Hazard 10
Stealth DC 29 (trained)
Description An object imbued with echoes of a vicious mind tries to kill someone who comes near.
Disable Religion DC 27 (master) to exorcise the spirit or Diplomacy DC 29 (expert) to talk it down
[[R]] Quietus (emotion, fear, illusion, mental, occult)
Trigger A creature moves within 10 feet of the haunted object.
Effect The haunt takes control of the triggering creature, forcing it to attack itself. The creature is affected by phantasmal killer (DC 25), except that instead of mental damage, the damage type is based on a weapon the creature has drawn, an object it holds, or its unarmed attack damage if it's holding nothing.
Here's an example of a haunt. As you can see, it uses the same basic framework as the other hazards, so once you learn the rules, you can use them flexibly for almost any hazard you can dream up! In this case, a PC could use Religion to exorcise the haunt, but a character could also potentially use Diplomacy to talk it down. Still, the master of Religion has the advantage with an easier DC. You could even imagine an adventure where it matters how the PCs deal with a hazard. Perhaps exorcising a haunt using Religion helps sanctify the area, while using Diplomacy might persuade the spirit to impart some hints to the PCs about what happened before it departs.
Spinning Blade Pillar Hazard 4
Complex, Mechanical, Trap
Stealth +10 (trained) or DC 24 (expert) to notice the control panel
Description A metal pole with three razor-sharp spinning blades is hidden in the floor, connected to trigger plates in up to eight floor tiles and a hidden control panel within 30 feet.
Disable Thievery DC 18 (trained) twice on the pillar, or Thievery DC 16 (expert) once on the control panel deactivates the entire trap
AC 19, TAC 15; Fort +6, Ref +10
Hardness 11 (2 dents) on the pillar, denting the panel causes the trap to stay constantly active and prevents disabling the panel; Immunities critical hits, object immunities, precision damage
[[R]] Rising Pillar (attack)
Trigger A creature steps on one of the floor tiles.
Effect The trap pops up in a grid intersection and makes a spinning blade attack against one adjacent creature (if any), then rolls initiative.
Routine (3 actions) On its initiative, the trap spends its first action making a spinning blade attack against each adjacent creature, its second action to move straight in a random direction (roll 1d4 to determine the direction), and its third action to attack each adjacent creature. This trap doesn't take a multiple attack penalty.
Speed 10 ft.
[[A]] Melee spinning blade +12, Damage 2d10+5 slashing
Reset The trap deactivates and resets after 1 minute.
This is the first complex trap ever created for the game. It was also responsible for the first death in the game, as Logan kept rolling randomly for the blade's movement, which just happened to be wherever Stephen's rogue had moved while trying to avoid it—and then it rolled right back over him after he fell unconscious. Note that the complex trap has a Stealth bonus, rather than just a DC, since it actually rolls for initiative in encounter mode (using Stealth). If your party has an expert in Thievery who can find the hidden panel (we didn't; our expert lay bleeding on the ground), this hazard is actually a breeze to disable, but even a trained character can disable it with patience, and a not-so-patient character can always smash it apart with enough big hits to deal 11 or more damage.
So what do you think? Care to hazard an opinion?