Poisonous

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Poisonous
Keyword Ability
Type	Triggered
Introduced	Future Sight
Last used	Future Sight
Reminder Text	Poisonous N (Whenever this creature deals combat damage to a player, that player gets N poison counters.)
Storm Scale	10
Scryfall Statistics
cards

Poisonous is a keyword ability that allows the use of multiple poison counters. It appeared as one of the various "futureshifted" mechanics of Future Sight, but was first designed for Tempest. It was reworked into the very similar ability toxic, a major mechanic in Phyrexia: All Will Be One.

Description

Poisonous has only been printed on two cards so far, the timeshifted Snake Cult Initiation and Virulent Sliver.

This was Mark Rosewater planting a flag in the ground that poison was going to return one day. He just keyworded how poison had always been used in the past. Poison would later return with Infect in Scars of Mirrodin, but Infect having more issues than anticipated, it opening up space for a Poisonous rework. With the release of Toxic, Poisonous was retired with a Storm Scale of 10.

During Future Sight design, poisonous was known as venom. However, it had already earlier been concepted as "poisonous" during the design of Tempest.

Rules

From the glossary of the Comprehensive Rules (July 25, 2025—Edge of Eternities)

Poisonous

A keyword ability that causes a player to get poison counters. See rule 702.70, “Poisonous.”

From the Comprehensive Rules (July 25, 2025—Edge of Eternities)

• 702.70. Poisonous
  • 702.70a Poisonous is a triggered ability. “Poisonous N” means “Whenever this creature deals combat damage to a player, that player gets N poison counters.” (For information about poison counters, see rule 104.3d.)
  • 702.70b If a creature has multiple instances of poisonous, each triggers separately.

Rulings

• If all damage that a poisonous creature would deal to a player is prevented, the poisonous ability won't trigger (see rule 119.8).
• The player will get the stated number of poison counters each time the poisonous creature deals combat damage to them, regardless of how much damage that creature dealt.
• If a player has ten poison counters, that player loses the game.
• Although several older cards give players poison counters, none of those cards have abilities that trigger on combat damage.

Examples

Example 1

Snake Cult Initiation
Enchantment — Aura
Enchant creature
Enchanted creature has poisonous 3. (Whenever it deals combat damage to a player, that player gets three poison counters. A player with ten or more poison counters loses the game.)

Example 2

Virulent Sliver
Creature — Sliver
1/1
All Sliver creatures have poisonous 1. (Whenever a Sliver deals combat damage to a player, that player gets a poison counter. A player with ten or more poison counters loses the game.)

Older cards

Many older cards referencing poison counters use a wording very similar to the poisonous keyword, but trigger on any damage, rather than just combat damage. To avoid changing functionality, no errata were made for these cards when the poisonous keyword was introduced.

• Crypt Cobra
• Marsh Viper
• Pit Scorpion
• Sabertooth Cobra
• Serpent Generator
• Suq'Ata Assassin
• Swamp Mosquito
• Leeches