Magic: The Gathering Advanced Guide

The Stack and Priority

The stack is MTG's system for resolving spells and abilities in the correct order. It's the single most misunderstood mechanic in the game and the key to intermediate and advanced play.

How the Stack Works

When a player casts a spell or activates an ability, it goes "on the stack" — it hasn't resolved yet. Both players receive priority in turn order to respond before anything resolves. The stack is LIFO (Last In, First Out) — the most recently added item resolves first.

In this example, Counterspell resolves first (countering the Lightning Bolt), then the stack is empty and your creature's enter-the-battlefield trigger resolves. The Lightning Bolt never resolved because it was countered.

Priority Rules

• After any player takes an action, priority returns to the active player (the player whose turn it is) first.
• When priority is passed by both players consecutively, the top item on the stack resolves.
• After resolution, the active player receives priority again.
• You can only cast instants and activate abilities while you have priority.
• During certain steps (like Cleanup), neither player normally receives priority unless a triggered ability triggers.

Instant Speed vs. Sorcery Speed

Instants can be cast whenever you have priority — including your opponent's turn, during combat, in response to spells, etc. Sorceries, creatures, enchantments, artifacts, and planeswalkers can only be cast during your main phase when the stack is empty and you have priority.

Split Second

Some cards have the Split Second keyword — while they're on the stack, no player may cast spells or activate non-mana abilities. This "breaks" the normal response window. Krosan Grip (destroy target artifact or enchantment) is famous for this — your opponent can't respond with a counterspell or sacrifice the target.

Replacement Effects

Replacement effects modify events before they happen — they don't use the stack. "If [X] would happen, [Y] happens instead." Leyline of the Void is a replacement effect (exiles rather than goes to graveyard). These interact with triggered abilities in subtle ways that require careful rule understanding.

The Layer System

When multiple continuous effects modify the same game object, they're applied in a specific order (Layers 1–8). This prevents contradictory results. The most commonly relevant layers for competitive play:

• Layer 6 — Ability adding/removing: "This creature loses all abilities" applies here.
• Layer 7b — Power/Toughness setting: Effects that set P/T to specific values.
• Layer 7c — P/T modifications: +X/+X effects apply here, after any setting effects.
• Layer 7d — Counters: +1/+1 and -1/-1 counters modify P/T last.

The practical impact: a 2/2 with "gets -1/-1" becomes 1/1, then if you cast a +3/+3 effect it becomes 4/4. The subtraction happens before the addition in this case because of timestamp order within layers. Understanding layers prevents mistakes with complex board states.

Format Deep Dives

Format Banned Lists

Each format maintains its own banned list. Modern's banned list (including Deathrite Shaman, Splinter Twin, Summer Bloom) reflects cards too powerful for that format's power level. Legacy's banned list is smaller. Understanding what's banned and why tells you a lot about what would break each format and helps you evaluate new cards for potential bans.

Mana Base Construction

The mana base — your lands and how you configure them — determines how consistently you can cast your spells on curve. A bad mana base makes even the best-built deck stumble.

Land Count by Deck Type

The Fetchland / Shockland System (Modern)

The gold standard Modern mana base uses Fetchlands (Scalding Tarn, Polluted Delta, Verdant Catacombs, etc.) to find Shocklands (Steam Vents, Breeding Pool, Hallowed Fountain, etc.). Fetchlands thin your deck (slightly increasing draw quality), enable instant-speed color fixing, and set up synergies with threshold/graveyard mechanics. Shocklands enter untapped if you pay 2 life, or tapped for free — competitively, you almost always pay the 2 life.

Fastlands, Checklands, Filterlands

• Fastlands (Copperline Gorge, etc.): Enter untapped if you control 2 or fewer other lands. Excellent in aggressive/tempo decks.
• Checklands (Dragonskull Summit, etc.): Enter untapped if you control a Mountain or Swamp (basic or relevant land type). Great alongside shocks/fetches.
• Filterlands (Fire-Lit Thicket, etc.): Pay 1 mana of one color to produce 2 of another. Exceptional for decks with demanding double-pip costs like {R}{R} or {G}{G}.
• Horizon lands (Sunbaked Canyon, etc.): Tap for mana or sacrifice to draw a card and lose 1 life. Provides late-game card velocity. Used in modern burn and midrange.

Color Ratio Calculation

Frank Karsten's mana base research (widely referenced in competitive MTG) provides probability tables for reliably hitting colored mana on specific turns. Key rules of thumb:

• To reliably cast a 1-drop requiring {R} on turn 1: run at least 14 red sources.
• To reliably cast a 2-drop requiring {W}{W} on turn 2: run at least 20 white sources.
• Each Fetchland searching a basic counts as that basic's color source.

Sideboard Theory

The sideboard is 15 cards you can swap in between games 2 and 3 of a match. You can make any number of swaps between games as long as your deck remains exactly 60 cards. Effective sideboard construction requires understanding the metagame and what cards efficiently answer specific threats.

Sideboard Archetypes

• Catch-all answers: Cards that answer multiple archetypes — Thoughtseize disrupts combo and midrange, Relic of Progenitus hates graveyard decks, Chalice of the Void stops low-curve strategies. Run fewer copies of more flexible answers.
• Hate cards: Narrow but extremely effective against specific archetypes. Leyline of Sanctity stops Burn targeting you and discard. Rest in Peace exiles graveyards completely. Damping Sphere stops Tron and Storm. Usually 2–3 copies of these.
• Threat upgrade: Sometimes you board in better threats for certain matchups — swap a slow card for a faster creature against aggressive decks.

The Sideboard 15 Framework

• 3–4 cards for your hardest matchup (the matchup you'd lose without help)
• 2–3 cards for your second hardest matchup
• 2–3 cards for graveyard hate (nearly always relevant)
• 2–3 cards for artifact/enchantment hate
• 2–3 flex spots (best cards for the expected metagame)

cEDH — Competitive Commander

cEDH (competitive Elder Dragon Highlander) is Commander played to win at the highest efficiency level, typically by turn 3–5. The politics of casual Commander disappear; every decision is optimized for winning.

cEDH Meta Concepts

• Fast Mana: Mana Crypt, Sol Ring, Chrome Mox, Mox Diamond, Lotus Petal, Ancient Tomb — produce mana significantly ahead of land drops. Essential in cEDH, banned or restricted in other formats.
• Stax: Taxing effects that slow all players down. If you're ahead, slowing everyone buys time to close. Rule of Law, Rhystic Study, Smothering Tithe.
• Turbo Ad Nauseam / Storm: Draw your entire deck and combo kill. Ad Nauseam pays life to draw; Storm copies spells for game-winning effect.
• Thoracle (Thassa's Oracle) Combo: Empty your library (via Demonic Consultation or Tainted Pact naming a card not in your deck), then cast Thassa's Oracle — win the game immediately even if your library is empty.
• Rule 0: cEDH tables agree on the power level before sitting down. A cEDH pod won't tolerate casual decks at the table; social dynamics are part of the format.