Introduction
Hazards are GM Core's answer to danger that is not just a creature swinging a weapon. They can be traps, haunts, environmental threats, collapsing rooms, magical engines, cursed relics, wilderness dangers, or encounter participants with routines.
Use this with GM guide, rules, combat, skills, equipment, classes, ancestry guides, and archetypes.
Fast Hazard Workflow
| Step | Question | Good output |
|---|---|---|
| 1 | What is the scene job? | Alarm, damage, delay, separation, clue protection, supernatural warning, terrain pressure, or resource drain. |
| 2 | What is the clue? | Scorch marks, old victims, strange silence, warped stone, residue, symbols, tracks, smell, or local warnings. |
| 3 | What detects it? | Perception, Thievery, Crafting, Survival, or a tradition skill. |
| 4 | What disables or bypasses it? | Tools, skill checks, magic, timing, alternate route, sacrifice, object interaction, or social knowledge. |
| 5 | What happens on failure? | Damage, condition, alarm, time loss, resource drain, separation, monster advantage, or changed environment. |
| 6 | What escalates? | Repeated routine, spreading danger, reinforcements, collapsing structure, rising water, or worsening curse. |
| 7 | What does success reveal? | Safety, treasure, clue, shortcut, tactical advantage, reputation, or control of the hazard. |
Hot take: if the only interaction is "take damage," the hazard is not a scene. It is a receipt.
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Player Core Foundation
Player Core matters because hazards ask players to use Perception, skill actions, movement, reactions, saves, conditions, tools, and spells. A hazard that can be noticed, understood, disabled, endured, bypassed, or exploited gives more characters a real turn.
| Player tool | Hazard use |
|---|---|
| Perception | Notice triggers, seams, pressure plates, magical oddities, hidden movement, and danger signs. |
| Thievery | Disable locks, triggers, mechanisms, traps, and delicate devices. |
| Crafting | Understand construction, repairs, alchemical residue, engineering, siege devices, and unstable structures. |
| Survival | Read natural hazards, tracks, weather, unstable ground, plants, animal signs, and wilderness danger. |
| Arcana | Identify runes, magical engines, arcane wards, and spell-shaped hazards. |
| Occultism | Interpret haunts, psychic residue, curses, dreams, and weird supernatural patterns. |
| Religion | Understand haunts, holy or unholy sites, undead traces, rituals, and divine wards. |
| Movement actions | Leap, Climb, Swim, Step, Take Cover, Escape, and Interact can be valid answers. |
Player Core 2 Updates
Player Core 2 makes hazards more interesting because new ancestries and classes bring different answers. Kobolds and Ratfolk can lean into traps, Crafting, and scrounging. Alchemists bring item answers. Investigators bring clue logic. Monks and Swashbucklers bring mobility. Champions can protect allies from the fallout.
Let those tools work. A Monk crossing a collapsing bridge quickly, an Investigator spotting the pattern, an Alchemist neutralizing a chemical leak, and a Champion protecting an ally from the aftermath are all wins for the system. The hazard should test the party, not pretend their sheets are decorative placemats.
GM Core Procedure
GM Core separates quick simple hazards from complex hazards that keep acting. The key is fairness. Hidden danger needs clues. Damage needs context. Disable routes need skills that match the fiction. Complex hazards should create choices during encounter mode instead of becoming automatic damage every round.
Simple Vs Complex Hazards
| Hazard type | Best use | GM warning |
|---|---|---|
| Simple hazard | A one-time trap, burst, alarm, collapse, poison needle, deadfall, or hidden magical strike. | The clue matters more because the scene may resolve quickly. |
| Complex hazard | A ritual engine, haunt, rotating blades, flooding room, living storm, siege device, or magical machine that acts over time. | Give players visible routines and ways to spend actions meaningfully. |
| Environmental hazard | Heat, cold, smoke, water, storms, altitude, disease, rubble, or unstable ground. | Use environment when the danger is ongoing terrain rather than a discrete trigger. |
| Encounter-integrated hazard | A trap or hazard that acts while monsters fight. | Count action pressure, not just XP math. Too many threats can dogpile the party. |
| Social or narrative hazard | Reputation traps, legal traps, cursed contracts, cult tests, magical bargains. | Make stakes and escape routes clear; do not hide the entire premise behind one secret roll. |
Telegraphing Without Spoiling
Telegraphing does not mean announcing the stat block. It means giving enough fiction that cautious players can choose caution.
| Clue type | Example use | What it rewards |
|---|---|---|
| Physical trace | Scorch marks, broken blades, cracked stone, blood trails, wet footprints | Perception, Crafting, Survival, tactical caution. |
| Sensory oddity | Silence, smell, vibration, cold air, flickering sparks, echo delay | Seek, Recall Knowledge, spell detection, slower exploration. |
| Victim evidence | Old skeletons, damaged armor, melted tools, abandoned packs | Inference, Medicine, Crafting, monster or hazard identification. |
| Local warning | Rumors, signs, maps, superstition, NPC fear | Social skills, research, preparation. |
| Pattern | Repeating pulses, rotating lenses, rising water, chanting cadence | Timing, Read the room, action planning. |
| Magical residue | Runes, holy symbols, psychic pressure, occult geometry | Arcana, Religion, Occultism, counteract planning. |
Hot take: "you did not say you checked the exact flagstone" is not clever GMing. It is a trust leak with masonry.
Quick Reference
| GM question | Use this when |
|---|---|
| Simple hazard | one burst of danger, quick resolution, strong clue required |
| Complex hazard | initiative, repeated effects, multiple rounds of interaction |
| Environmental hazard | terrain or climate as the threat |
| Haunt or magical hazard | lore, tradition skills, and story clues matter |
Fair Hazard Design
A fair hazard telegraphs itself before it hurts the party. Use suspicious architecture, residue, scorch marks, supernatural silence, broken tools, old victims, warnings, or NPC behavior. Let different skills reveal different truths: Perception spots the trigger, Thievery handles the mechanism, Crafting understands construction, Religion identifies a haunt, Arcana reads a rune, and Survival reads natural danger.
Detection, Disable, Bypass, And Exploit
For important hazards, prep more than "detect or take damage." Strong hazard scenes usually have four layers.
| Layer | What it means | Example |
|---|---|---|
| Detect | Notice that something is wrong. | The altar hums when metal approaches. |
| Understand | Learn what kind of danger it is. | Religion identifies it as a haunt tied to broken vows. |
| Disable | Stop or suppress the hazard. | Thievery jams the mechanism, Religion performs a rite, Crafting vents pressure. |
| Bypass | Avoid the danger without disabling it. | The party takes a side passage, uses cover, times movement, or sends a decoy. |
| Exploit | Turn the hazard into an advantage. | Lure enemies into the rune, redirect steam, use the alarm to mislead guards. |
Not every hazard needs every layer. A quick pit trap can be simple. A campaign-important haunted gate should have more than one way for the table to engage.
Hazards That Include More Players
A good hazard gives different characters different ways to help. The Rogue can disable the trigger, the Wizard can identify the magic, the Cleric can recognize a haunt, the Fighter can hold a door against a moving blade, the Druid can read natural danger, the Alchemist can neutralize a chemical threat, and the Investigator can piece together clues before anyone touches the suspicious altar. Build hazards with at least two interaction paths whenever the stakes are high. If only one trained skill can participate and failure means damage, the scene will feel narrow. If multiple approaches reveal partial truths, the hazard becomes a table problem instead of a tax.
Hazard Roles In Encounters
| Role | What it does | Good pairing |
|---|---|---|
| Alarm | Changes the next scene if ignored. | Guards, stealth missions, faction bases, urban play. |
| Divider | Splits movement or line of sight. | Skirmishers, bridges, doors, collapsing halls. |
| Timer | Forces action before the room worsens. | Rituals, flooding, fire, unstable magic. |
| Punisher | Punishes a specific behavior like clustering or rushing. | Brutes, controllers, defensive enemies. |
| Objective | Must be disabled, redirected, protected, or survived to win. | Boss fights, rituals, siege scenes. |
| Clue lock | Protects information rather than treasure. | Investigations, tombs, secret societies, cult sites. |
| Terrain engine | Changes the battlefield every round. | Complex hazards, magical rooms, machinery. |
Use encounter building and adjusting encounters when a hazard and monsters both pressure the party. A hazard that consumes actions can make an encounter harder even when the creature math looks polite.
Example Hazard Skeletons
| Concept | Type | Clue | Interaction paths |
|---|---|---|---|
| Oathbroken chapel haunt | Complex haunt | Whispered vows repeat whenever a weapon is drawn. | Religion calms it, Occultism reads the pattern, Diplomacy addresses the spirit, retreat and apology change the scene. |
| Alchemical pressure room | Complex mechanical hazard | Pale vapor leaks from cracked pipes and dead vermin lie near vents. | Crafting vents pressure, Thievery locks valves, alchemical items neutralize residue, Athletics opens a jammed hatch. |
| Collapsing rope bridge | Environmental/simple hazard | Frayed ropes, missing planks, and wind stress are visible before crossing. | Acrobatics crosses carefully, Athletics secures ropes, Crafting repairs, ranged support covers, flight or climbing bypasses. |
| Whispering legal contract | Narrative hazard | Clauses rewrite themselves when spoken aloud. | Society identifies legal traps, Occultism detects binding magic, Diplomacy renegotiates, Deception creates a loophole. |
| Siege rune mortar | Encounter-integrated hazard | The rune flashes in a repeating cadence before each shot. | Arcana disrupts timing, Crafting damages the mount, movement avoids marked zones, enemies can be baited into fire. |
These are not stat blocks. They are prep frames: clue, type, responses, and table role first; numbers second.
Hazard Prep Template
For each hazard, write trigger, clue, detection, disable, consequence, escalation, and bypass. Trigger is what sets it off. Clue is what fair play gives before the trigger. Detection is how the party notices it. Disable is how they interact with it. Consequence is what happens if they fail. Escalation is how it changes if ignored. Bypass is how clever players avoid it. This template keeps hazards from becoming surprise damage. It also gives Player Core and Player Core 2 characters room to contribute through Perception, Thievery, Crafting, tradition skills, Survival, mobility, alchemy, and protective reactions.
Hazard Prep Checklist
| Prep line | Fill it in |
|---|---|
| Trigger | What starts the hazard: movement, sound, magic, light, blood, theft, time, proximity, or a failed disable attempt. |
| Clue | What players can notice before triggering it. |
| Detection | Which senses, skills, exploration activities, or magic can reveal it. |
| Interpretation | What a successful check teaches beyond "trap here." |
| Disable | Which skills, tools, spells, rituals, or actions stop it. |
| Bypass | How clever play avoids it without solving it. |
| Escalation | What gets worse if the party waits or fails. |
| Reward | Treasure, clue, shortcut, safety, reputation, or tactical advantage. |
| Failure consequence | Damage, condition, alarm, separation, time loss, resource drain, or worsened encounter state. |
Treasure Vault And Equipment Hooks
Hazards are where gear should matter. Rope, poles, light sources, tools, climbing gear, repair kits, containers, alchemical items, scrolls, and protective consumables all become more interesting when the environment asks for them. Use equipment, adventuring gear, alchemical items, consumables, and Treasure Vault when hazards are a recurring campaign pillar.
Common Mistakes
| Mistake | Fix |
|---|---|
| Treating the rule as isolated math | Connect it to character choices, scene stakes, and consequences. |
| Ignoring Player Core 2 options | Check whether new ancestries, classes, archetypes, feats, spells, or items change the party's tools. |
| Hiding every procedure | Keep mystery in the fiction, not in the basic rules the players need to make decisions. |
| Overbuilding the scene | Use the lightest GM Core procedure that creates useful pressure. |
| Giving no clue before harm | Add visible, audible, social, magical, or environmental warning signs. |
| Making one skill the whole solution | High-stakes hazards should allow multiple ways to learn, disable, bypass, or mitigate the danger. |
| Forgetting action pressure | A complex hazard that acts during combat changes encounter difficulty through actions, not just numbers. |
| Treating hazards as gotchas | Hazards should reward attention and preparation, not punish players for failing to read the GM's mind. |
| Ignoring consequences after success | Disabling a hazard can create treasure access, a shortcut, reputation, clues, or control of the battlefield. |
| Reusing the same trap shape | Mix alarms, timers, haunts, terrain engines, social traps, and environmental dangers. |
Best Links
Use Thievery, Crafting, Survival, Arcana, Occultism, Religion, detection and senses, environment, encounter building, adjusting encounters, skill check DCs, subsystems, and equipment.
Hot Take
A trap with no clue is not clever. It is just a damage tax wearing a disguise.
