Utility

Utility cards are the flex slots. They don't fit neatly into ramp, draw, removal, or your strategy-specific categories. They answer specific problems, provide niche effects, or shore up weaknesses.

These slots change based on your playgroup. If you're playing against a lot of graveyard decks, load up on graveyard hate. If everyone runs artifacts, run more artifact removal. Utility is your response to the metagame.

Graveyard hate

Your opponents will use their graveyard. Even decks that aren't graveyard-focused benefit from recursion. Having at least one piece of graveyard hate is worth it.

Bojuka Bog — a land that exiles a player's graveyard when it enters. Costs you nothing but entering tapped.
Soul-Guide Lantern — 1 mana artifact, exile a card or sacrifice to exile all graveyards and draw. Low opportunity cost.
Rest in Peace — 2 mana enchantment, exiles everything going to graveyards. Shuts down all graveyard strategies. Don't run this if your own deck uses the graveyard.
Scavenger Grounds — colorless land, sacrifice to exile all graveyards. Another low-cost inclusion.

Haste enablers

Haste lets your creatures attack or use tap abilities the turn they enter. Especially valuable for commanders.

Lightning Greaves — also provides shroud. Already in most decks for protection.
Swiftfoot Boots — also provides hexproof. Same.
Concordant Crossroads — 1 mana enchantment, all creatures have haste. Helps opponents too. Best when your deck benefits more from haste than theirs.
Anger — a creature that gives all your creatures haste when it's in your graveyard and you control a Mountain. Self-mills and discard put it where it needs to be.

Artifact / enchantment staples

Cards that handle problematic artifacts and enchantments efficiently.

Reclamation Sage — 3 mana creature, destroys an artifact or enchantment on ETB. Good in creature toolbox and blink decks.
Acidic Slime — 5 mana creature, destroys an artifact, enchantment, or land. Deathtouch body.
Foundation Breaker — 4 mana creature with evoke for {1}{G}. Flexible between a body or a cheap removal spell.

Utility lands

Lands that provide effects beyond mana. These cost you a slot in your mana base but don't cost a spell slot.

Rogue's Passage — makes a creature unblockable. Voltron and creature-heavy decks.
War Room — draw a card for mana plus life. Colorless card draw available to any deck.
Reliquary Tower — no maximum hand size. Only run this if you regularly draw 10+ cards at once.
Command Beacon — puts your commander in your hand, bypassing command tax.
Boseiju, Who Endures — channel to destroy an artifact, enchantment, or nonbasic land. Can't be countered. Excellent in any green deck.

Meta-dependent choices

These cards are good against specific strategies:

Vs. token decks: Rakdos Charm, Elesh Norn, Massacre Wurm
Vs. voltron: Sacrifice effects (Fleshbag Marauder, Grave Pact)
Vs. combo: More counterspells, more targeted removal, Rule of Law effects
Vs. stax: Artifact/enchantment removal density goes up

If you don't know your metagame (playing at a new LGS, online), default to flexible answers. Beast Within, Chaos Warp, and generic graveyard hate cover the widest range of problems.