Trap Generator

Design fully mechanized D&D 5e traps — trigger, detection DC, disarm method, damage, saving throws, area of effect, and GM notes — scaled to your party and ready to run at the table.

Quick Start

1. Navigate to Generate → Trap Generator
2. Choose a Category (Mechanical, Magical, or Environmental)
3. Set the Difficulty (Simple through Deadly)
4. Select a Theme that matches your dungeon
5. Set Party Level and Party Size using the sliders
6. Optionally specify a Damage Type or enable Complex Trap mode
7. Click Generate Trap
8. The trap appears in the right panel with all mechanics ready to use

Form Inputs

Category (Required)

The fundamental nature of the trap's mechanism:

Mechanical — Physical devices built from gears, springs, and pressure-sensitive mechanisms. Detected with Perception and disarmed with Thieves' Tools. Examples: pressure plates that launch crossbow bolts, tripwires that drop portcullises, counterweight crushing ceilings.

Magical — Arcane constructions powered by glyphs, runes, or stored spells. Detected with Arcana or Investigation; Detect Magic also reveals them. Dispel Magic can suppress or remove them. Examples: spell-triggered alarm glyphs, arcane fire runes, teleportation circles that send victims elsewhere.

Environmental — Hazards created by the dungeon's natural or architectural conditions rather than deliberate construction. Examples: unstable floors over deep pits, natural gas pockets ignited by torches, flood channels that fill on a timer, rot-weakened bridges.

Difficulty (Required)

Scales all DCs and damage values to produce an appropriately dangerous trap for your party:

Theme (Optional)

Ties the trap's flavor, name, and construction to the location:

Party Level (Slider, 1–20)

Scales damage dice and DC values to remain relevant to your party's tier. A trap that is Dangerous for level 3 characters should produce meaningfully different numbers than Dangerous for level 13 characters.

Party Size (Slider, 1–8)

Informs area-of-effect sizing. Larger parties spread through corridors differently, and the generator calibrates how many targets a trap is likely to catch.

Damage Type (Optional)

Prefer a specific type of damage for the trap's effect. Useful when you want thematic consistency with the dungeon (fire traps in a volcanic temple, cold traps in a frost giant's stronghold, necrotic traps in an undead crypt):

Acid, Bludgeoning, Cold, Fire, Force, Lightning, Necrotic, Piercing, Poison, Psychic, Radiant, Slashing, Thunder

Leave this blank for the generator to choose a type appropriate to the category and theme.

Complex Trap (Optional Toggle)

Standard traps are discrete events — triggered once, effect applied, done. Complex traps are multi-stage hazards that run on initiative. They work more like monsters:

• The trap has an initiative count and takes "actions" each round
• Multiple active elements run simultaneously (spinning blades AND a rising ceiling AND fire jets)
• The trap evolves over its duration — conditions worsen as rounds progress
• The encounter ends when the trap is disarmed or all characters escape or fall

Complex traps are high-preparation, high-drama set pieces. Use them for important dungeon rooms, final approaches to a villain's lair, or any time you want a trap to be the entire encounter rather than a speed bump.

Additional Notes (Optional, 500 characters)

Specific design requests:

• "Hidden behind a secret door; the pressure plate is under the welcome mat"
• "Targets only the first creature to enter; others can see it trigger"
• "The trap has already been partially triggered — one element is broken"
• "Must work in a room full of treasure the players can't destroy"
• "Should be subtle enough that players might not realize it triggered until they're already hurt"

What Gets Generated

Quick Reference Card

A condensed summary for immediate use at the table:

• Detection DC: Active Perception check to spot the trap
• Disarm DC: Thieves' Tools or relevant skill check to deactivate it
• Save DC: Saving throw DC (if the trap has a saving throw)
• Damage: Dice expression and damage type
• Effect: Primary condition or secondary effect applied

Print Card

A condensed table reference with trigger, effect, and counterplay — formatted to copy into your session notes.

Trigger

How the trap activates:

• Type: Pressure plate, tripwire, proximity, touch, sight, verbal, time delay, magic, and more
• Description: Exactly how and when it fires in narrative terms
• Area of Effect: Single target, line, cone, sphere, burst, or cube; with dimensions in feet

Detection

How the party can find the trap before triggering it:

• Active DC: Perception check (or other skill) to spot it while searching
• Passive Perception DC: What passive score automatically notices it (typically Active DC + 5)
• Search Methods: Which skills apply — Investigation, Perception, Survival, or Arcana
• Visual/Physical Clues: 1–3 specific things a perceptive character might notice (scratches on the floor, faint smell, hairline crack in the ceiling)

Disarming

What it takes to safely neutralize the trap:

• Skill and DC: Which skill (usually Thieves' Tools) and what DC
• Time Required: Instant, Action, Bonus Action, 1 minute, or 10 minutes
• Failure Consequence: Exactly what happens if the disarm attempt fails
• Retryable: Whether the character can try again after failure

Effect

The full mechanical consequence of triggering:

• Damage: Dice expression, type, and whether a saving throw halves it
• Saving Throw: Ability (STR/DEX/CON/INT/WIS/CHA), DC, and what a success vs. failure means
• Conditions: Any status conditions applied (poisoned, restrained, blinded, etc.) and their duration
• Secondary Effects: Additional consequences beyond the primary damage or condition

Reset Mechanism

Whether and how the trap resets:

• Single Use: Fires once and is done
• Manual Reset: Requires a creature to physically reset it (a lever, a key)
• Automatic Reset: Resets on its own after a set time — the corridor is dangerous again in 10 minutes

Magical Properties (Magical Traps Only)

• School of Magic: Which school powers the trap (Evocation, Abjuration, Enchantment, etc.)
• Detect Magic: What Detect Magic reveals when cast near the trap
• Dispel Magic Effect: Exactly what happens if a caster Dispels the trap — suppressed temporarily, destroyed, or triggering its effect on the caster

Creature Interaction (Where Applicable)

Tactical notes for using the trap alongside a monster encounter:

• Synergy: Which creature types or specific monsters work well with this trap
• Tactics: How aware creatures use the trap to their advantage (herding players toward it, timing ambushes after it fires)
• Positioning: Where to place guards relative to the trap's area of effect

Complex Trap Details (Complex Mode Only)

• Initiative Count: When the trap acts in initiative order
• Active Elements: Named simultaneous effects with their individual actions and timing
• Round Duration: How many rounds the trap runs before expiring
• Dynamic Change: How the trap escalates — what changes between round 1 and round 3
• Escape Plan: How characters can exit the trap's area entirely

GM Notes and Warnings

Optional notes generated alongside the mechanics:

• Warnings: Rules interactions to be aware of (e.g., how flight interacts with the trigger)
• GM Notes: Suggested read-aloud descriptions, timing advice, and pacing suggestions

XP and Encounter Budget

Every trap includes an XP value and a brief encounter budget statement (e.g., "Medium encounter for 4 level 5 PCs"). Use this to track trap XP alongside monster XP for the session.

Tips & Best Practices

Tell the players about the trap before it fires. D&D 5e design philosophy assumes players have a reasonable chance to detect traps before triggering them. Run the detection phase honestly. If the rogue rolls a 22 Perception and the DC is 15, they notice it — even if triggering the trap would be dramatically convenient for you.

The clues section is your read-aloud trigger. Before the party enters a trapped room, pick one clue from the detection section. Work it into your room description. "The dust on the floor has a strange pattern — there's a clean line about four feet in, as if something sweeps the floor there." This rewards attentive players without telegraphing everything.

Disarm failure consequences make traps memorable. The standard consequence is "trap triggers". But some traps generate more interesting failure consequences — the mechanism jams and the trap can't be disarmed at all, or the failure sets a timer, or the trap fires at the person attempting the disarm rather than the normal trigger zone. Read the generated consequence and lean into it.

Complex traps need a physical map. Before running a complex trap in session, sketch the room. Mark where each active element operates. Mark the escape routes. Know exactly where the safe zones are. Complex traps that aren't clearly spatially understood at the table devolve into "take damage and make saves" very quickly.

Use the creature interaction notes. A trap designed to work with a specific monster type is twice as dangerous as a standalone trap, and half the effort to run. If the notes suggest "goblin ambush", position three goblins on a ledge overlooking the pressure plate. They know it's there. The party doesn't.

Environmental traps reward exploration, not punishment. A natural gas pocket that ignites when someone carries an open flame is a different design than "fireball when you walk in". The first rewards players who think before acting. The second rewards paranoia. Consider which behavior you want to encourage.

Vary reset mechanisms across a dungeon. If every trap in the dungeon is single-use, players stop respecting them after the first triggered trap. Mix in some auto-resetting traps — especially at chokepoints players might retreat through. A "safe" corridor becoming dangerous again on the return trip is a useful pressure tool.

Scale to party tier, not to punish. A Deadly trap is designed to be genuinely life-threatening, not automatically lethal. Use Deadly difficulty for traps you want the party to work hard to avoid or overcome, not as a gotcha. Simple and Moderate traps are the workhorses — they create tension without threatening a TPK from a single bad initiative roll.