Relentless Rats Deck Guide: Breaking the Four-Copy Rule
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Relentless Rats is a three-mana 2/2 from Fifth Dawn (2004) whose text overrides one of Magic's core deckbuilding rules: a deck can have any number of cards named Relentless Rats. Each Rat gets +1/+1 for every other creature named Relentless Rats on the battlefield, so the more you jam, the bigger they all get.
It was the first card to break the four-copy limit this way, and twenty years later it still defines an entire archetype: the deck where the answer to every deckbuilding question is 'more Rats.'
How the rule exception works
Normally a constructed deck can include at most four copies of any card that isn't a basic land. Relentless Rats carries its own printed exception, and the game rules explicitly allow a card's text to override deck construction limits. The ability functions before the game begins — it's not something an opponent can interact with.
In Commander the same text overrides the singleton rule, so a 100-card deck can legally run dozens of Rats plus a commander. The exception applies only to cards that say so; you can't extend it to anything else in the deck.
Building the swarm
The classic shell is mono-black: a critical mass of Rats, a handful of tutors and removal spells, and Swamps. Most builds land somewhere between twenty and thirty copies — enough that every draw step improves the board, while leaving room for the support cards that stop the deck from folding to a single sweeper.
The signature power play is Thrumming Stone. Ripple 4 means each Rat you cast reveals four more cards and casts every Relentless Rats among them for free — and each of those Rats ripples again. With a deck that's mostly Rats, one three-mana creature routinely becomes an entire battlefield.
In Commander, Marrow-Gnawer is the traditional general: he gives Rats fear and multiplies the swarm. Swarmyard, an old favorite land, regenerates a Rat for free each turn and keeps the engine running through removal.
- Core: 20-30+ copies of Relentless Rats and reliable ways to keep the mana flowing
- Thrumming Stone: the ripple engine that dumps the swarm in one turn
- Marrow-Gnawer: the go-to Commander general for Rat tribal
- Support: cheap removal, card draw, and recursion to survive board wipes
The family it started
Relentless Rats spawned a whole lineage of any-number cards, each with its own archetype: Shadowborn Apostle for demon summoning, Rat Colony for faster, cheaper swarms, Persistent Petitioners for mill, Dragon's Approach for spellslinger burn, Slime Against Humanity for graveyard-fueled oozes, and Hare Apparent for white weenie swarms. Seven Dwarves plays a capped variant of the same idea.
The original remains the most iconic. Rat Colony copies hit harder per mana but die to a stiff breeze; Relentless Rats grow in both power and toughness, which is why the old Rats still win the long game.
Collecting a deck that's mostly one card
Buying twenty-plus copies changes how you shop. The Fifth Dawn original has been joined by multiple reprints over the years, plus the Year of the Rat Secret Lair with alternate art, so you can chase a matching playset aesthetic or mix printings for character. Individual copies are typically a few dollars or less, so even a full swarm is one of the cheapest tribal decks you can assemble — foils and the Secret Lair versions are where completionists spend real money.
Relentless Rats printings tracked on RareWell
| Card | Set | Rarity | Price |
|---|---|---|---|
| Relentless Rats | Secret Lair Drop | rare | $153 |
 Relentless Rats | Secret Lair Drop | rare | $98 |
 Relentless Rats | Secret Lair Drop | rare | $95 |
 Relentless Rats | Secret Lair Drop | rare | $90 |
 Relentless Rats | Secret Lair Drop | rare | $88 |
 Relentless Rats | Secret Lair Promo | rare | $24 |
 Relentless Rats | Magic 2011 Promos | rare | $20 |
 Relentless Rats | Secret Lair Promo | rare | $8.04 |
Collections featuring Relentless Rats
1 public collector has this card on RareWell — tap through to see it in their collection.
Cards mentioned in this guide
Frequently asked questions
- How many Relentless Rats should I put in a deck?
- Most 60-card builds run 20-30 copies; Commander decks often go higher. The floor is wherever the swarm stops being reliable — below roughly twenty, the pump effect and Thrumming Stone both lose their punch.
- Does Relentless Rats count opponents' Rats too?
- Yes. Each one gets +1/+1 for every other creature named Relentless Rats on the battlefield, regardless of who controls it. In a Rat mirror, everyone's Rats get huge.
- Is Relentless Rats legal in Commander?
- Yes. Its printed text overrides the singleton rule, so you can run any number of copies alongside your commander — Marrow-Gnawer is the traditional choice.
- How does the Thrumming Stone combo work?
- Thrumming Stone gives your spells ripple 4: when you cast a Rat, reveal the top four cards and cast any copies of Relentless Rats among them for free. Each free Rat ripples again, frequently chaining most of your deck onto the battlefield.