The Swarm

Introduction

Swarm Mode is a cooperative variant of Commander for 1–5 players. Survivors (players) team up against an automated opponent called The Swarm, or face off against one player acting as The Overlord! Face overwhelming waves of creatures and Enforcers, survive the onslaught, and empty The Swarm’s deck to claim victory!

Swarm Mode is an unofficial cooperative variant compatible with Magic: The Gathering® Commander format. Swarm Mode is not affiliated with or endorsed by Wizards of the Coast LLC. Magic: The Gathering® is a registered trademark of Wizards of the Coast LLC, a subsidiary of Hasbro, Inc. All Rights Reserved.

Components & Setup

Survivor Setup

Each Survivor (1–5) prepares for the game as follows:

• Choose a Commander deck (casual power level recommended)
• Survivors form a team with a shared life total of 40 life
• Reminder: Survivors each take three full turns before The Swarm takes its first turn

The Swarm Setup

• The Swarm uses one Swarm Deck with accompanying Enforcers. No preparation needed — shuffle and play!
• Enforcers are sleeved separately and are never shuffled into The Swarm’s deck.
• Shuffle the Enforcer Stack and place it face-down. (See Enforcers & The Lair)

Format Rules

The following rules replace standard Magic rules for all Survivors:

• Vigilance has no effect for Survivor creatures. All attacking Survivor creatures tap as normal (this includes abilities that function like Vigilance as well)
• Lifelink only triggers when a creature attacks. Life is not gained from blocking.
• Special Statuses (such as the Monarch or the Initiative) and voting effects do not apply in Swarm Mode.
• Commander Damage does not apply. Only life totals and poison counters matter.

Win & Loss Conditions

Core Rules

The Swarm’s Characteristics

• The Swarm has no maximum hand size and no life total
• If The Swarm would gain life, take that many cards from the bottom of The Swarm’s Graveyard and place them on the bottom of The Swarm’s deck.

Milling and Poison Counters

• Damage dealt to The Swarm and life loss both mill The Swarm (one card per point of damage or life lost). This includes combat damage, damage from spells or abilities, and life loss effects. Mill effects targeting opponents have no effect on The Swarm. Only damage and life loss cause The Swarm to mill.
• The Swarm cannot receive poison counters. Damage from sources that would add poison counters to The Swarm only deals damage; the poison counter effect is ignored.

Mana and Costs

• The Swarm has no lands but has infinite mana of all colors, and can pay all mana costs including colored mana costs, and X always = 0
• The Swarm always pays additional costs (Kicker, Multikicker, Entwine, Escalate, Overload, Buyback, Bargain, Boast, Casualty, Collect Evidence, Discard, Echo, Offspring, etc.) when beneficial.

Creature Rules

• All Swarm creatures enter the battlefield untapped with Haste and must attack each combat if able. Any card text that would cause a Swarm creature to enter tapped is ignored.
• Swarm creatures with Defender or 0 or less power cannot attack.
• When a Swarm creature dies, it goes to the Graveyard (including tokens, treated as 0-cost creature cards). If a Swarm creature changes control, it loses Haste (unless printed on the card) and is no longer forced to attack.
• Swarm Creatures always choose the +1/+1 counter for abilities like Fabricate, Riot, or Unleash.
• Swarm creatures with Adventures automatically cast the Adventure spell before entering the battlefield, if it can be legally cast. The creature then enters the battlefield as normal.

Targeting and Effects

• “Each player” effects: Trigger once for each Survivor, plus once for The Swarm.
• “Each opponent” and “target opponent” effects: For life loss or poison, treat Survivors as a single team. Otherwise, “each opponent” triggers once per Survivor; “target opponent” targets one Survivor. (See Hive Mind or Overlord Mode for decision-making.)
• “You/Your” on Swarm cards: Refers to The Swarm; “defending player” refers to a Survivor.
• Annihilator: When a Swarm creature with Annihilator attacks, Survivors collectively choose which permanents to sacrifice from any Survivor’s battlefield, totaling the required number.
• Turn/Phase/Step Skipping: Has no effect. The Swarm always progresses through all phases normally.
• Vow cards only prevent attacks against the Survivor who controls them, not the Survivor team as a whole.

Countering Effects

• When a Survivor counters a Swarm spell, exile it instead. At the end of The Swarm’s turn, return it to hand.

Enforcers & The Lair

The Lair

• The Lair is the zone where Enforcers wait until they enter the battlefield. The face-up card on top is the Active Enforcer.
• Whenever an Enforcer leaves the battlefield for any reason (including being destroyed, exiled, bounced, or tucked) it is moved to the bottom of The Lair instead.

The Active Enforcer

• Static abilities on the Active Enforcer are in effect while in The Lair, if possible.
• Abilities that require it to be in play (attacking, blocking, etc.) do not apply while in The Lair.
• Survivors cannot target or interact with Enforcers in The Lair.

Emergence

• The Enforcer Stack starts face-down. At the start of The Swarm’s first turn, reveal the top card face-up as the Active Enforcer. It does not enter the battlefield this turn.
• Beginning on The Swarm’s second turn, the Active Enforcer enters the battlefield at the start of each Swarm turn. The next card in The Lair becomes the Active Enforcer. It is not cast and cannot be countered.
• If The Lair is empty, there is no Active Enforcer until one returns.

While in Play

• An Enforcer on the battlefield follows all Creature Rules (see Core Rules).
• Enforcers are Swarm creatures. All rules that apply to Swarm creatures apply to Enforcers unless otherwise stated.

Dread Level

The Reckoning

• One Reckoning card (a noncreature card) is shuffled into the Enforcer stack at setup. When The Reckoning is revealed as the Active Enforcer, it does not enter the battlefield. Instead, insert it face-up approximately halfway into the Swarm deck. The next Enforcer in The Lair becomes the Active Enforcer as normal.
• When The Reckoning is reached during the Swarm Step, or milled through damage or life loss, it resolves immediately and unconditionally. It cannot be countered, redirected, etc. After resolving, remove it from the game.
• Survivors cannot interact with The Reckoning while it is in the Swarm deck.

Turn Structure

Survivor Turns

At the start of each round, Survivors collectively agree on the turn order for that round. They may change the order each round.

The Swarm’s Turn

After Survivors each complete their third turn, The Swarm begins taking turns. Each Swarm turn follows this sequence:

Hive Mind Mode

In Hive Mind Mode, The Swarm operates autonomously. All decisions are made collectively by Survivors, always choosing what is most advantageous to The Swarm.

Hand Management

• The Swarm’s hand is kept face-down.
• Cards returned to hand are placed face-down.
• When forced to discard, discard a random card/cards from hand.

Pre-Swarm Step

• Cards with Foretell in hand are cast before other cards during the Pre-Swarm Step. The Swarm never proactively exiles cards using the Foretell mechanic.
• Shuffle The Swarm’s hand.
• Randomly reveal and cast cards one at a time, fully resolving each before revealing the next.
• Cards drawn during this step go to hand, are shuffled in, and are cast this same step.
• Continue until hand is empty.

Combat

• Attacking: All Swarm creatures that are able to attack must do so (See Creature Rules). If any attackable non-player permanents are in play, roll a d6 for each attacking Swarm creature: on a 5 or 6, that creature attacks a random attackable non-player permanent. All remaining creatures attack Survivors.
• Blocking: Untapped creatures block, assigned to The Swarm’s advantage. If at least one attacking creature remains unblocked, reveal cards from the bottom of The Swarm’s Graveyard one at a time until a creature is revealed (non-creature cards revealed are shuffled and returned to the top). That creature enters the battlefield untapped and blocks the Survivor’s highest-power unblocked attacking creature. This happens once per combat, regardless of how many creatures remain unblocked.
• Damage Assignment: When an attacking Swarm creature is blocked by multiple creatures, assign lethal damage to the highest toughness blocker first, then the next highest, until all damage is assigned.

Decision Making

• Survivors (as a group) make all choices most advantageous to The Swarm.
• Triggered abilities with optional costs (e.g., “you may pay {2}:”) are never activated.
• The following are determined randomly: “target opponent” effects (unrelated to life loss/poison), “defending player” effects, which Survivor is targeted when “each opponent” triggers separately, and any other choice with no determinable advantage.
• When choosing a creature card in the Graveyard, prioritize nontoken cards first.

Overlord Mode

In Overlord Mode, a player called The Overlord controls The Swarm directly, making decisions personally instead of relying on automated rules.

Hand Management

• The Swarm’s hand is known to The Overlord (not face-down).
• Cards returned to hand are known to The Overlord.
• When forced to discard, The Overlord chooses which card(s) to discard.

Pre-Swarm Step

• Cards with Foretell in hand are cast before other cards during the Pre-Swarm Step. The Overlord never proactively exiles cards using the Foretell mechanic.
• Token cards in hand must be cast before anything else this step; The Overlord casts them in any order.
• The Overlord may cast any nontoken cards from hand, in any order, or may stop and hold any remaining nontoken cards in hand.
• Cards drawn during this step go to hand and may be cast this same step (and must be cast if they are tokens).

Combat

• Attacking: All Swarm creatures that are able to attack must do so (See Creature Rules). The Overlord decides how to divide attackers among all attackable targets.
• Blocking: The Overlord may assign blocks using any untapped Swarm creature(s).
• Damage Assignment: When an attacking Swarm creature is blocked by multiple creatures, the Overlord assigns lethal damage to blockers in any order of their choosing.

Second Main Phase

• The Overlord may play any nontoken cards they wish from hand.

Decision Making

• The Overlord makes all choices for The Swarm.
• Triggered and activated abilities with optional costs (e.g., “pay {2}: Do X.”) may be activated up to Dread Level times per turn, counting all such activations across all cards combined.
• The Overlord chooses any/all targets for The Swarm.

Ban List Philosophy

This format bans any card that makes The Swarm completely ineffective or provides Survivors with an overly easy path to victory.

Quick Reference

Setup

• Survivors: 40 shared life, 10 poison limit
• The Swarm: Pre-constructed deck
• Enforcers: Shuffle separately, place face-down

Game Flow

• Survivors each take 3 turns before The Swarm starts
• Turns alternate between The Swarm and Survivors
• The Swarm’s turn: Beginning Phase → First Main Phase (Pre-Swarm Step, then Swarm Step) → Combat → Second Main Phase → End
• Pre-Swarm Step: Shuffle hand, then cast all cards one at a time
• Swarm Step: Reveal and resolve cards until a nontoken card with mana value greater than Dread Level is cast

Key Rules

• Damage/Life loss to The Swarm = Mill cards
• Life gain to The Swarm = shuffle cards from Graveyard, place on bottom of deck
• The Swarm’s hand is face-down; shuffle at start of each Pre-Swarm Step
• Cards drawn during Pre-Swarm are shuffled in and cast that turn
• Swarm creatures can attack immediately and must attack if able; always enter untapped
• Countered spells return to The Swarm’s hand at end of turn (delay, not removal)
• Commander damage does not apply
• On The Swarm’s first turn, the Active Enforcer is revealed but does not enter the battlefield
• Attackable permanents (Hive Mind): Roll d6 per attacker — 5 or 6 attacks a random attackable non-player permanent, 1–4 attacks Survivors

Win Conditions

• Survivors win: Empty The Swarm’s deck AND battlefield (hand doesn’t matter)
• Survivors lose: 0 life, any player deck empty, or 10 poison counters

Glossary

Active Enforcer — The face-up card at the top of The Lair. Its static abilities are in effect while in The Lair. Beginning on The Swarm’s second turn, it enters the battlefield at the start of each Swarm turn.

Dread Level — A number equal to the number of Enforcers currently on the battlefield. Dread Level changes immediately whenever an Enforcer enters or leaves the battlefield. It determines how far the Swarm Step progresses each turn.

Emergence — The process by which the Active Enforcer enters the battlefield at the start of each Swarm turn.

Enforcer — A Swarm creature kept in a separate stack called The Lair. Enforcers enter the battlefield one per Swarm turn and follow all Creature Rules.

Hive Mind — The automated mode of play in which The Swarm operates without a controlling player. All decisions are made collectively by Survivors, always choosing what is most advantageous to The Swarm.

Milling — The primary way The Swarm loses cards from its deck. Damage dealt to The Swarm and life loss both mill The Swarm one card per point.

Pre-Swarm Step — The first part of The Swarm’s First Main Phase, during which The Swarm casts all cards from its hand.

The Reckoning — A noncreature card shuffled into the Enforcer stack at setup. When revealed as the Active Enforcer, it is inserted face-up into the middle of the Swarm deck and resolves immediately when reached.

Survivor — A player on the cooperative team opposing The Swarm. Survivors share a life total of 40 and win by emptying The Swarm’s deck and battlefield.

Swarm Step — The second part of The Swarm’s First Main Phase, during which cards are revealed and resolved from the Swarm deck until a nontoken card with mana value greater than the current Dread Level is cast.

The Lair — The zone where Enforcers wait before entering the battlefield. The face-up card on top is the Active Enforcer. Survivors cannot target or interact with cards in The Lair.

The Overlord — An optional player who controls The Swarm directly in Overlord Mode, making all decisions personally instead of relying on automated rules.

The Swarm — The automated opponent in Hive Mind Mode, controlled collectively by Survivors always choosing what is most advantageous to it.

Swarm Mode is an unofficial cooperative variant compatible with Magic: The Gathering® Commander format. Swarm Mode is not affiliated with or endorsed by Wizards of the Coast LLC. Magic: The Gathering® is a registered trademark of Wizards of the Coast LLC, a subsidiary of Hasbro, Inc. All Rights Reserved.

Questions? jason@quorumgames.com