DnD Poison Rules and Types

Poison in Dungeons & Dragons represents one of the oldest and most mechanically layered hazard categories in the game, spanning contact toxins, ingested compounds, inhaled vapors, and injury-based venoms. The rules governing poison interact with saving throws, conditions, damage types, and item acquisition in ways that require precise interpretation at the table. This page covers the 5th Edition rules framework for poison as published in the Player's Handbook and Dungeon Master's Guide, including poison types, application methods, mechanical effects, and the decision points that most frequently generate table disputes.

Definition and scope

Under the 5th Edition rules, poison is both a damage type and a category of hazardous substance. These two uses are distinct: a creature can deal poison damage without administering a poison, and a poison substance can impose the Poisoned condition without necessarily dealing poison damage.

The Dungeon Master's Guide (Chapter 8, "Traps") and the Player's Handbook equipment chapter both address poison substances. The free D&D Basic Rules (Wizards of the Coast / D&D Beyond) also reference basic poison as a purchasable item. The broader D&D rules framework treats poison as an environmental and equipment hazard, placing it in the same regulatory space as disease, exhaustion, and other debilitating conditions.

The Poisoned condition, as defined in the rules, imposes 2 specific penalties:
1. Disadvantage on attack rolls
2. Disadvantage on ability checks

This condition is mechanically identical regardless of which poison substance caused it, making the condition itself a reliable reference point across all poison types.

How it works

The 5th Edition Dungeon Master's Guide defines 4 poison delivery methods:

1. Contact — Takes effect when it touches exposed skin. No action is required from the target; touching a coated surface or object is sufficient.
2. Ingested — Must be swallowed. Mixing into food or drink is the standard method. A creature that only tastes rather than swallows takes no effect in most rulings.
3. Inhaled — Dispersed as a gas or powder, typically affecting all creatures within a defined area. Creatures that do not breathe (undead, constructs) are generally immune.
4. Injury — Introduced through a wound. The DMG specifies this applies when a coated weapon hits a creature. A weapon holds one application of injury poison, and the coating typically remains effective for 1 minute or until the weapon hits.

Each poison type has its own Constitution saving throw DC, onset time (instantaneous or delayed), and duration. Basic Poison — the entry-level purchasable item priced at 100 gold pieces — is an injury poison with a DC 10 Constitution save. On a failed save, the target takes 1d4 poison damage and is Poisoned for 1 hour. This contrasts sharply with higher-tier substances: Midnight Tears, for example, has a DC 17 save and deals 9d6 poison damage, activating only at midnight on a failed save.

The saving throw mechanics governing poison follow the standard Constitution save resolution: the target rolls a d20, adds their Constitution modifier and any relevant proficiency, and compares to the substance's DC. Creatures with resistance to poison damage halve the damage result. Creatures with immunity to the Poisoned condition or poison damage — including most undead and many constructs — ignore both effects entirely.

Advantage and disadvantage interact with poison saves when a creature has multiple sources of resistance or vulnerability, following the standard rule that these never stack beyond a single instance.

Common scenarios

Coated weapon timing: A Rogue or Ranger applying poison to a weapon mid-combat uses an action (or bonus action for certain class features). The action economy cost is a standard tactical cost players must weigh carefully. The coating is destroyed on the first successful hit; a miss does not consume the application.

Trap-delivered poison: Trap rules frequently pair mechanical triggers with poison mechanisms — a needle trap in a lock, a dart from a pressure plate. The DMG's trap construction guidance assigns these a save DC and damage value consistent with encounter level. See the encounter building framework for appropriate calibration.

Resistance stacking: Creatures with natural poison resistance (Dwarves via Dwarven Resilience, for example) have advantage on saving throws against poison in addition to resistance to poison damage. These are 2 separate benefits that coexist; advantage on the save does not negate the damage resistance, and vice versa.

Disease overlap: Poison and disease are related but distinct categories. The disease rules operate on different save schedules and do not interact mechanically with poison immunity or resistance unless a specific ability explicitly states otherwise.

Decision boundaries

The most contested rulings in poison adjudication cluster around 4 specific boundaries:

1. Does tasting trigger an ingested poison? The rules do not explicitly address partial ingestion. Most DMs rule that tasting without swallowing does not trigger the effect, consistent with the "must be swallowed" language in the DMG.
2. How long does a weapon coating last? The DMG states 1 minute. If a combat extends beyond 10 rounds — a rare but possible scenario — the coating expires unused.
3. Does Paladin Aura of Protection apply to poison saves? Yes. Aura of Protection adds the Paladin's Charisma modifier to all saving throws for nearby allies, and Constitution saves against poison are saving throws under standard rules.
4. Can a creature notice poison in food? A Wisdom (Perception) check or Intelligence (Nature/Medicine) check at DM-assigned difficulty class is the standard adjudication. No automatic detection exists in the base rules; noticing requires an active check. The skills and proficiencies framework governs which check applies.

The full rules index provides cross-references to related condition and hazard categories. For sustained poison effects that require tracking across multiple rounds — such as the Serpent Venom poison which deals 3d6 damage per failed save over 24 hours — exhaustion may also accrue if the DM incorporates optional lingering injury rules from the DMG.

References

• D&D Basic Rules — Wizards of the Coast / D&D Beyond
• D&D 5th Edition Player's Handbook — Wizards of the Coast
• D&D 5th Edition Dungeon Master's Guide — Wizards of the Coast
• D&D Beyond Rules Glossary — Conditions Reference