Grixis Affinity Sideboard Guide

Introduction

Grixis Affinity is one of the most-played decks in Pauper, at 6.1% of the field. The plan is easy to state: flood the battlefield with artifact lands and cheap artifacts, then cast creatures printed at four, five, and seven mana for one or two while drawing enough cards to replace whatever the opponent answers. A one-mana Myr Enforcer with a fresh hand behind it is the deck in a single image. The fun is in the ordering: every land drop and artifact changes what the rest of your hand costs, and finding the line that ends in a free 4/4 and a two-card refill never gets old.

Its matchup spread is comfortable. The deck is at its best against slower blue decks that try to answer threats one for one, because most of its cheap artifacts draw a card on the way out and every new threat demands a fresh answer: it is favored against Dimir Faeries and Jeskai Ephemerate, and slightly favored against Blue Terror. Spell-based combo decks such as Ruby Storm are also clearly favorable ground. Against Mono Red Madness, itself 8.6% of the field, the games are close to even.

The trouble spots are specific rather than general. Elves is unfavored, Monster Tron is clearly the worst of the popular matchups, and aggressive white creature decks such as White Aggro are slightly unfavored. Everywhere else, expect close games decided by sequencing.

General Strategy

Everything in Grixis Affinity runs through one number: how many artifacts you control. Nineteen of the twenty lands are artifacts, the cheap spells either are artifacts or feed on them, and the payoff cards - Myr Enforcer, Refurbished Familiar, Utrom Monitor, and Thoughtcast - each cost one less to cast for every artifact on your side. The board that makes your mana is also the board that discounts your spells. Your job as the pilot is to grow that artifact count cheaply, sequence so it is at its highest when the big spells go down, and then convert the discount into oversized creatures and extra cards. Do it well and you are casting bigger spells on less mana than most opponents can match.

The engine is a set of artifacts that replace themselves. Ichor Wellspring draws a card when it enters and another when it goes from the battlefield to the graveyard. Blood Fountain puts two artifacts into play for one mana, counting its Blood token. Reckoner's Bargain converts any of those pieces into two cards plus life, and Thoughtcast refills the hand for one or two mana once a few artifacts are down. Because every piece pays itself back, the count climbs without really spending a card. The discounts are free.

Left alone, the deck curves out like this. Turn one, Vault of Whispers into Blood Fountain - with the Blood token, that is already three artifacts. Turn two, Great Furnace into Ichor Wellspring draws a card and makes five. Turn three, Seat of the Synod is the sixth artifact, so Myr Enforcer costs a single mana, and once it is in play Thoughtcast costs just one blue mana and draws two. Turn four adds Refurbished Familiar for one black mana, forcing a discard, while Myr Enforcer attacks for 4. From there the game ends the way most Affinity games end: Refurbished Familiar and Utrom Monitor attack in the air, Myr Enforcer rules the ground, and Makeshift Munitions converts leftover artifacts into the last points of damage.

When the opponent does interact, the deck leans on its draws instead of its board. Ichor Wellspring and Nihil Spellbomb trade themselves for cards, Reckoner's Bargain cashes in anything already doomed, and Blood Fountain returns dead creatures from your graveyard to your hand for four mana, so most removal fails to answer a threat permanently. Galvanic Blast and Krark-Clan Shaman hold off attackers while the next wave gets cheaper. You rarely need the first board to survive. The second one costs less and arrives with a fuller hand.

Two weaknesses are built into the plan. Half the mana base - the ten bridge lands - enters tapped, so the first turns are slow and a fast opponent lands real damage before the discounts come online; accept some early life loss and plan to stabilize rather than race. And the sacrifice outlets need fodder: Reckoner's Bargain, Krark-Clan Shaman, and Makeshift Munitions all sit idle when the cheap artifacts run out, so spend artifacts with the next sacrifice in mind instead of feeding every outlet the moment it is available.

The Cards

Ichor Wellspring

The engine's centerpiece and the best two mana the deck spends. It draws a card when it enters and another when it goes from the battlefield to the graveyard, so it raises the artifact count while replacing itself twice over. That second trigger makes it the premier fodder in the deck: every sacrifice outlet gains a card when this is what pays the cost. Cast it early even with nothing else going on; both halves come back around.

Blood Fountain

One black mana buys two artifacts, counting the Blood token it creates when it enters, and nothing grows the count faster than that. The Blood token is a small luxury later: one mana, a tap, a discard, and its own sacrifice trade the worst card in your hand for a new one. The card's own ability is the deck's mana sink and recursion in one: four mana with a tap and its sacrifice return up to two creature cards from your graveyard to hand. While it sits in play, removal on your creatures is never a permanent answer.

Reckoner's Bargain

Instant-speed conversion: sacrifice an artifact or creature as part of the cost, draw two cards, and gain life equal to the sacrificed permanent's printed mana value. The fodder choice matters - a Blood token banks nothing while Myr Enforcer banks 7 - and Ichor Wellspring is the default because its death trigger deepens the exchange. Its other job is rescuing a creature from targeted removal.

Thoughtcast

Printed at five mana and almost never cast for more than two. With a developed board it costs a single blue mana and draws two cards, which is the rate that lets the deck treat every threat as replaceable. Cast the turn's affinity creature first, since the new artifact discounts this too - the standard double-spell turn is threat first, then . It is the card that makes the second wave automatic.

Role Assignment

Grixis Affinity is a midrange deck with a deep card-advantage engine, a tempo-neutral start, and medium inevitability. It out-resources fair decks in a long game, but it does not automatically win the longest game, and its clock - flyers closing around turn six - is unhurried. Those traits fix the roles below, and they fix the terrain too: nearly every matchup is contested on the same four axes. Can removal attack the artifact count profitably, or does it trade down against pieces that draw a card as they die? How much damage do the tapped-land turns concede? Can one-for-one answers keep pace with the draws and Blood Fountain rebuys? And who owns the air while ground creatures play under the threat of Krark-Clan Shaman?

Vs. Aggro. You are the control. The tapped lands concede the first turns, the clock cannot win a pure race, and the whole matchup lives on the damage-during-setup axis - so do not fight over it. Trade early, spend Galvanic Blast on the attacker that hurts most, wall the ground with Myr Enforcer, and bank life with Reckoner's Bargain and Toxin Analysis. The role-defining play is the stacked Krark-Clan Shaman sweep: several activations at once clear a wide board in a single exchange while your flyers survive untouched. Once the board is stabilized, your draws bury them.

Vs. Midrange. You are the control first and the beatdown later, because attrition favors you. Spot removal trades down against artifacts that replace themselves, and up to two of the creatures that do get answered, Blood Fountain can return - most of those exchanges leave you even or a card ahead. Once the answers thin out, flip roles and push the air-war axis: Refurbished Familiar and Utrom Monitor attack over a ground that cannot profitably cross into Myr Enforcer. The defining play is rebuying a killed threat with Blood Fountain and redeploying it at a discount - the exchange that proves the resource war is unwinnable for the other side.

Vs. Control. You are the beatdown, and an unusually durable one. Spot removal is exactly what the artifact count blanks: cheap answers trade down against artifacts that draw on the way out, so the first axis is yours by default, and your draws keep threats flowing faster than one-for-ones can answer them. The real risks are a sweeper, mass artifact removal, and counterspells on the key threat, so deploy one discounted threat at a time with a rebuilt wave behind it rather than emptying the hand at once. is the role in one card: a flyer that lands for as little as one mana with three artifacts already out, forcing a discard on arrival, pressure and disruption together. Your inevitability is only medium, though - against a dedicated late game, keep a clock going rather than settling into a pure resource war.

Play Patterns

Play every artifact you can before casting an affinity spell, and hold sacrifice effects until after it is cast. Affinity checks the artifact count as the spell's cost is locked in, and everything counts: artifact lands, Blood tokens, Clue tokens. Each artifact that hits play first shaves one mana off the spell; each artifact you sacrifice first puts one back on. A validated line shows the stakes. Turn one, Vault of Whispers into Blood Fountain makes three artifacts with the token; turn two, Great Furnace into Ichor Wellspring makes five and draws a card. On turn three, play Drossforge Bridge first for six - a tapped artifact still counts - then cast Nihil Spellbomb for seven, and Myr Enforcer is free with Great Furnace still untapped. Cast Myr Enforcer before Nihil Spellbomb and it costs one mana; cast it before the land drop and it costs two. Misordering the same cards routinely wastes one to three mana a turn.
Decide how big a Krark-Clan Shaman sweep you need, then put every activation on the stack before the first one resolves. Krark-Clan Shaman is itself a 1-toughness creature without flying, so the first activation that resolves kills it and no further activations are possible - but activations already announced still resolve after it dies. If the board needs 2 or 3 damage, sacrifice two or three artifacts up front and let the whole stack resolve. Refurbished Familiar and Utrom Monitor fly over every activation; Myr Enforcer does not, so count its 4 toughness into the total before you go past three.
When removal targets a big affinity creature - or you need life in a race - cash the creature to Reckoner's Bargain in response. The life gained equals the sacrificed permanent's printed mana value, not the discounted price you paid, so banks 7 life plus two cards while a Blood or Clue token banks zero. Because the sacrifice is part of the cost, the creature is already gone when the removal spell tries to resolve: it has no target left and does nothing. You turn a clean answer into two cards and 7 life.

Black Sacrifice

Carrion Feeder - emblematic card for this matchup

Matchup - Favored

We take the control role here despite being the midrange deck. Black Sacrifice is the aggressor: a curve of almost nothing but one-mana creatures comes out ahead of our tapped-land development, so they press the race and we break it. Speed is theirs, and so are the sideboard and the play/draw split, but the cards are ours. Their interaction is a thin package of Snuff Out and Accursed Marauder that trades one-for-one at best, while Galvanic Blast, Krark-Clan Shaman sweeps, and Makeshift Munitions strip a board of 1-toughness creatures faster than the death-trigger tokens rebuild it - and their rebuild is tokens while ours is cards. Their race stays live only while a grown Carrion Feeder dodges our removal long enough for Rite of Consumption to convert it. Keeps follow from the role: weigh interaction over raw engine, because a hand that spends its opening turns only building the artifact count lets Carrion Feeder grow past our answers. The bar rises on the draw, where their swarm gets a full extra attack before our tapped lands come online.

Kill Carrion Feeder, Mortician Beetle, and whatever wears Sadistic Glee as early as the mana allows. The window is real: with spare fodder in play they grow the target in response to Galvanic Blast, and once counters push it past four toughness the spell still resolves but no longer kills. Early is the only clean shot. Krark-Clan Shaman covers the swarm itself, and because its cost has no tap symbol it sweeps at instant speed even the turn it enters - stack several sacrifices in one window to scale the sweep past counters, with Ichor Wellspring and Blood tokens as the fodder. If a creature wearing Sadistic Glee would live through the sweep, hold it until Toxin Analysis makes the damage lethal at any size; a sweep that leaves the carrier alive hands it a counter for every creature dying under it.

The board plan is a ground wall plus fliers. Myr Enforcer holds the ground - breaking through a discounted 4/4 costs them several sacrificed bodies fed to Bloodthrone Vampire - while Refurbished Familiar and Utrom Monitor race overhead past everything except the flying Insect token Infestation Sage leaves behind. Refurbished Familiar is the safest attacker: the black body dodges Snuff Out, and once their hand is empty the enters trigger draws us a card instead. When removal does come, cash the target: Reckoner's Bargain in response to Snuff Out, or to an Accursed Marauder trigger that would take our best creature, blanks the answer and banks two cards plus life equal to the creature's full mana value - seven off Myr Enforcer - and that life comes straight out of the Rite of Consumption drain math. Hold Nihil Spellbomb for the graveyard windows that matter: cracked in response to Unearth targeting Accursed Marauder or to a Supernatural Stamina death trigger, it leaves the return with nothing to find, and with black mana open it replaces itself.

Key Threats

Carrion Feeder is their fastest clock and the one creature that outgrows our removal if ignored. Every expendable body becomes a permanent counter at instant speed for no mana, and because it cannot block, it never slows our fliers - the race it creates is a pure damage exchange. Passing turns with it alive is the losing pattern: spare fodder lets them grow it in response to our burn, and once it sits past Galvanic Blast range and too big for a Myr Enforcer block, only the Toxin Analysis plus Krark-Clan Shaman line pulls the game back. Kill it on sight.

Rite of Consumption is why their race threatens even a stabilized board. The finish is one attack followed by the drain in their second main phase, so their biggest creature's power hits our life total twice in a single turn, and the drain half gains them that damage back as life - a gap that looked safe closes at once. The creature is sacrificed as a cost when the spell is cast, so removal in response no longer shrinks the drain. The defense happens earlier: keep the life race wide and kill the grown attacker before that turn exists.

Accursed Marauder is their cleanest answer to Myr Enforcer. The forced sacrifice ignores targeting and the 4/4 body, and our creature count is lean enough that the choice is often no choice. Deploying threats one at a time feeds it: each copy trades an expendable 2/1 for our best creature, while their own half of the trigger eats a body whose death pays them in tokens and triggers. Hold Reckoner's Bargain for the trigger when the doomed creature matters, and remember Unearth rebuys it for a second trigger unless Nihil Spellbomb strips the graveyard first.

Mortician Beetle turns our own lines against us. It grows whenever either player sacrifices a creature, so Reckoner's Bargain or Makeshift Munitions cashing a creature hands it a counter - even the response that blanks Snuff Out grows it a step closer to outsizing our blockers. It dies on sight, and while it lives, Ichor Wellspring and other noncreature artifacts become the preferred fodder.

Sideboard Plan

In:

2 Extract a Confession
1 Krark-Clan Shaman

Out:

1 Cryogen Relic
2 Nihil Spellbomb

Extract a Confession comes in for the creature that grows past Galvanic Blast range. With evidence 6 collected - easy off a spent Thoughtcast plus any one-mana card - each opponent sacrifices their greatest-power creature, taking the grown Carrion Feeder or Sadistic Glee carrier. Never cast it without evidence here: the base mode lets them hand over a death-trigger body and grow Mortician Beetle. Instant-speed dodges are plentiful, though - they can cash the big creature to a draw spell like Village Rites or eat it for free with Carrion Feeder or Bloodthrone Vampire - so assume the grown threat gets sacrificed in response whenever an outlet is up; only Rite of Consumption is stuck at sorcery speed and cannot.

The fourth Krark-Clan Shaman comes in because drawing a sweep on time is the highest-leverage variable in the pairing. Every mainboard creature they play has 1 toughness, so one activation clears everything but a grown payoff and the flying Insect token Infestation Sage leaves behind, and the extra copy matters because each one dies to its own activation and to the -1/-1 death trigger from Shambling Ghast.

Cryogen Relic goes out as the slowest card in the list in the matchup where their speed is the whole threat. Two mana of setup against a swarm of one-mana creatures never keeps pace: by the time it deploys and activates the board is already wide, and stunning one tapped attacker does little when Nested Shambler and Infestation Sage deaths rebuild the swarm for free.

Two copies of Nihil Spellbomb go out because their graveyard only matters in narrow windows - an Unearth rebuy of Accursed Marauder or a Supernatural Stamina return - and one held copy covers those at instant speed while still counting as a cheap artifact. Extra copies are redundant exile against a deck that wins from the battlefield, and the slots become removal for grown creatures.

Sideboarding shifts the pairing moderately toward them. Twelve of our fifteen sideboard slots are anti-red and anti-blue blasts with no target in a mono-black deck, so we upgrade three cards while they bring in cheap removal and hand attack aimed straight at our plan. We stay favored across the match, but post-board games run closer than game one.

Post-board Strategy

The engine stays intact after boarding, but the removal upgrades on both sides: Extract a Confession answers the grown Carrion Feeder that Galvanic Blast cannot, while their cheaper, denser removal makes every creature we tap out for less safe. Run the same game plan as game one with better top-end answers. Pay the evidence with spells and spent trinkets - Thoughtcast plus any one-mana card covers the six - so creature cards stay in the graveyard for Blood Fountain rebuys, and the clean timing for Extract a Confession is our main phase, after the threat has outgrown Galvanic Blast but before they can line up the attack into Rite of Consumption. The remaining Nihil Spellbomb becomes a bullet: hold it for the Unearth or Supernatural Stamina window rather than cracking it early for the draw.

Tragic Slip is the removal to respect most. It kills any of our creatures for one mana - a creature dying is trivial for them, so the -13/-13 mode is effectively always on - and it reaches the black Refurbished Familiar that Snuff Out cannot touch, taking away our safest game-one attacker. Some lists add extra copies of Snuff Out, still effectively free, and some bring Spinning Darkness, often-free 3 damage that kills Utrom Monitor and Krark-Clan Shaman; Myr Enforcer survives it, and it cannot target the black Refurbished Familiar. No creature we tap out for is unconditionally safe anymore.

Expect Mesmeric Fiend to take Thoughtcast, Reckoner's Bargain, or a held answer, and with a sacrifice outlet on the battlefield they can sacrifice it while its enters trigger is still on the stack, exiling the taken card for good - do not count on getting the card back. Against removal-dense draws, lean harder on the lines that beat one-for-one answers: Reckoner's Bargain responses, Ichor Wellspring as fodder, and Blood Fountain returning Myr Enforcer and Refurbished Familiar. That conversion turns their best removal draws into a long game their deck cannot win.

Grixis Affinity

Decklist

Introduction

General Strategy