The London Mulligan Rule
The London Mulligan is the official mulligan rule for all sanctioned Magic: The Gathering formats. It was formally adopted in July 2019 following a trial period at Mythic Championship London, replacing the Vancouver Mulligan that had been in use since 2015. The rule governs how players may redraw their opening hand at the cost of reducing the number of cards they ultimately keep.
The procedure is as follows. At the start of each game, every player draws an opening hand of seven cards. A player who is dissatisfied with the hand may declare a mulligan, shuffle the entire hand back into the library, and draw a fresh hand of seven cards. After drawing, that player must place a number of cards from the new hand on the bottom of the library in any order, equal to the total number of mulligans taken during that game. The remaining cards constitute the kept hand.
In practical terms, a first mulligan results in drawing seven cards and placing one on the bottom, leaving the player with six. A second mulligan means drawing seven again and placing two on the bottom, keeping five. The process may continue—drawing seven and putting three back to keep four, and so on—until the player chooses to keep or is reduced to a single card. Once a player keeps, the game proceeds to the first turn.
The critical advantage of the London Mulligan over its predecessors is that the player always sees a full seven cards before deciding which to relinquish. This grants significantly more agency in sculpting a functional hand, even at reduced hand sizes. A five-card hand under the London Mulligan tends to be considerably more competitive than a five-card hand under older systems, because the player selects which five to retain from a pool of seven rather than simply receiving five random cards.
Mulligan History
The mulligan rule has undergone three major revisions since its introduction to tournament play. Understanding the evolution helps clarify why the London Mulligan represents the most equitable system to date.
The Paris Mulligan was the original tournament mulligan rule used for many years. Under this system, a player who chose to mulligan would shuffle the hand back and draw one fewer card. The first mulligan produced a six-card hand, the second a five-card hand, and so on. The fundamental weakness of the Paris Mulligan was that players had no control over which cards they lost. A player mulliganing to five simply received five random cards from the deck, with no ability to shape the hand. This made aggressive mulliganing extremely punishing and created situations where the player who mulliganed was at a severe, often insurmountable disadvantage.
The Vancouver Mulligan was introduced in 2015 as an incremental improvement. It retained the Paris Mulligan's core mechanic of drawing one fewer card per mulligan, but added a scry 1 after the player decided to keep a mulliganed hand. This single scry provided a marginal amount of card selection—the player could look at the top card of the library and choose to leave it or send it to the bottom. While this was a step forward, the improvement was modest. The player still had no choice in which cards were lost during the mulligan itself; the scry merely offered a small correction after the damage was done.
The London Mulligan, adopted in July 2019, resolved the core problem by separating the acts of drawing and reducing. By always drawing seven and then choosing which cards to put back, the player retains full agency over hand composition. This was particularly significant for formats where specific cards or combinations are essential. The London Mulligan was tested at Mythic Championship London in early 2019, where it received overwhelmingly positive reception from both players and coverage teams. Wizards of the Coast subsequently announced it as the permanent rule for all formats.
The London Mulligan is widely considered superior for competitive play because it reduces the variance penalty of mulliganing while still maintaining a meaningful cost (fewer total cards). Games are decided more often by strategic play and less often by one player being locked into an unplayable hand after a single mulligan.
Evaluating Opening Hands
The decision to keep or mulligan an opening hand is among the most impactful choices in a game of Magic. A strong opening hand establishes tempo, deploys threats on curve, and ensures access to the colors of mana required by the deck. A weak hand forces the player to spend early turns recovering rather than executing a game plan. The following framework breaks down keepable hand criteria by the four primary deck archetypes in constructed play.
Aggressive Decks
Aggressive strategies live and die by their opening turns. The primary goal is to deploy threats as early as possible and maintain pressure before the opponent can stabilize. A keepable aggro hand should contain two to three lands and at least one creature or spell that can be deployed on turn one. The ideal hand includes a one-drop creature, a two-drop follow-up, and enough mana to cast both on curve.
Hands with four or more lands are generally mulligans for aggro decks, as flooding out removes the speed advantage that justifies playing an aggressive strategy. Similarly, a hand with only one land is risky unless the deck has an extremely low mana curve (average mana value below 1.5) and the single land provides access to the deck's primary color. Under the London Mulligan, aggressive decks benefit greatly from the ability to put back excess lands while keeping a concentrated set of efficient threats.
The clock—the number of turns needed to reduce the opponent from 20 life to 0—is a critical consideration. A keepable aggro hand should project a kill by turn four or five in most 60-card constructed formats. If the hand cannot do this, a mulligan is likely correct even if the hand appears superficially functional.
Midrange Decks
Midrange strategies occupy the middle ground between aggression and control, relying on individually powerful cards played on curve. A keepable midrange hand typically contains three lands and a sequence of plays spanning turns two through four. The hallmark of a strong midrange opener is flexibility: the ability to deploy a threat and hold up interaction, or to play defensively against aggro while maintaining pressure against control.
Because midrange cards tend to have high individual impact, these decks can afford to be somewhat less aggressive with mulligan decisions than other archetypes. A seven-card hand with three lands and a reasonable curve is almost always a keep, even if it lacks a specific removal spell or bomb. However, hands that are missing the deck's primary colors of mana or that offer no play before turn three should be mulliganed, as midrange decks without early interaction can fall too far behind against faster strategies.
Interaction is the secondary priority after curve. A midrange hand with three creatures and no removal can be overrun by a faster aggro draw, while a hand with all removal and no threats will struggle to close the game. The best midrange hands contain a mix of both.
Control Decks
Control strategies aim to answer threats, generate card advantage, and win the game in the later turns. A keepable control hand requires three to four lands, at least one piece of early interaction (a removal spell or counterspell), and ideally a source of card advantage to sustain the long game. Control decks can tolerate higher land counts in the opening hand because they need to make land drops consistently through turns four, five, and beyond.
The most dangerous trap for control players is keeping a hand that is entirely reactive with no card advantage engine. A hand of four lands, two removal spells, and a counterspell looks appealing in theory, but if the opponent deploys threats faster than the control player can answer them one-for-one, the game is lost. Prioritize hands that include a card draw spell, a planeswalker, or another source of repeatable advantage alongside the necessary interaction.
Against aggressive matchups, early removal is paramount. A control hand with three lands and a two-mana removal spell is often a keep even without card draw, because surviving the early game is the first priority. Against slower matchups, card advantage and counter-magic take precedence over spot removal.
Combo Decks
Combo decks have the most polarized mulligan decisions because their game plan revolves around assembling specific cards or reaching a critical game state. A keepable combo hand contains either key combo pieces or reliable ways to find them, such as tutors, cantrips, or card filtering effects. Two or more lands are generally required to begin executing the plan.
Combo decks mulligan more aggressively than any other archetype. A five-card hand containing a tutor, two lands, and a protection spell is frequently superior to a seven-card hand filled with cards that do not advance the combo. Under the London Mulligan, combo players benefit enormously from the ability to see seven cards and keep only the relevant ones, discarding redundant or irrelevant pieces.
Protection is the tertiary consideration after combo pieces and mana. In formats with prevalent disruption (counterspells, hand attack, removal for combo creatures), keeping a hand with a combo piece and a way to protect it is significantly better than keeping a hand that assembles the combo but folds to a single removal spell.
Land Count and Keepable Hands
The number of lands in a deck directly determines how often the opening hand contains a functional mana base. For a standard 60-card constructed deck running 24 lands, the probability of drawing exactly two, three, or four lands in the opening seven cards is approximately 77.5%. This means roughly three out of every four hands will fall within the acceptable land range for most strategies.
Decreasing the land count shifts the distribution toward fewer lands per hand. A deck with 20 lands will see a higher proportion of one-land and zero-land hands, which is acceptable for aggressive decks with very low curves but dangerous for anything else. Increasing the land count to 26 or 27 shifts the distribution upward, making three- and four-land hands more common while reducing the risk of mana screw—at the cost of increasing the frequency of five-land hands that may lack sufficient spells.
The relationship between land count and keepable hand rate is one of the most important deckbuilding considerations. Players who find themselves mulliganing frequently should examine whether their land count is appropriate for their curve. The ScrollVault Mana Base Calculator provides detailed land count recommendations based on color requirements, mana curve, and format, and the Hypergeometric Calculator can compute exact probabilities for any combination of deck size, desired cards, and sample size.
How to Use This Simulator
The Opening Hand Simulator allows players to test mulligan decisions with any deck before committing to a game. The process involves three steps.
Step 1: Load the decklist. Copy a decklist from any deck builder—Moxfield, Archidekt, MTGA export, or a plain text list in the standard format (e.g., "4 Lightning Bolt"). Select the appropriate format from the dropdown menu to set the expected deck size: Standard (60), Modern (60), Commander (99), or Limited (40). Click "Load Deck" to parse the list. The simulator will display deck statistics including total card count, unique cards, and a breakdown by card type.
Step 2: Draw an opening hand. Click "Draw Hand" to shuffle the deck using a Fisher-Yates algorithm and deal seven cards. Card images are loaded from Scryfall, providing a visual representation of the hand. The stats bar beneath the hand displays the number of lands, non-lands, average mana value of cards in hand, and the colors of mana available.
Step 3: Evaluate and decide. Assess the hand against the keepable hand criteria for the deck's archetype. Click "Keep" to lock in the hand, or click "Mulligan" to shuffle and draw seven new cards. On a mulligan, the simulator will prompt the player to select cards to place on the bottom of the library, faithfully implementing the London Mulligan rule. The number of cards to be bottomed equals the total number of mulligans taken. Click "New Hand" at any time to reset and start a fresh draw.
Repeated iterations build pattern recognition. By drawing dozens of hands with a given decklist, a player develops an intuitive understanding of which hands are keepable and which demand a mulligan—knowledge that translates directly to faster, more confident decisions at the table.
Understanding the Statistics Panel
After a deck is loaded, the simulator's WebAssembly (WASM) engine runs 50,000 simulated opening hands in the background at native speed. WASM—short for WebAssembly—is a binary instruction format that allows code compiled from languages like C or Rust to execute in the browser at near-native performance. This enables the simulator to complete all 50,000 trials in seconds rather than minutes, with no server round-trip required. The results populate four key statistics.
Keep 7 represents the percentage of simulated games in which the initial seven-card hand met keepable criteria: at least two lands, at least one non-land spell, and access to the deck's primary color of mana. A well-constructed 60-card deck typically produces Keep 7 rates between 75% and 90%. Rates below 70% suggest a structural problem with the mana base or the deck's color requirements.
Mull to 6 indicates how often the first hand was unsuitable and a single mulligan was required. For most decks this figure falls between 8% and 18%. A Mull to 6 rate above 20% is a strong signal that the land count, color distribution, or both need adjustment.
Mull to 5 and Mull to 4 track the frequency of deeper mulligans. These should be rare events in a healthy deck. If the Mull to 5 rate exceeds 5% consistently, the deck likely has a fundamental construction issue that the Mana Base Calculator can help diagnose.
Average starting hand size is the mean number of cards kept across all 50,000 simulated games. This is a single-number summary of the deck's mulligan profile. A value above 6.5 indicates a consistent deck that rarely needs to mulligan. Values between 6.0 and 6.5 are acceptable but suggest room for improvement. Values below 6.0 indicate serious mana base problems.
Commander Mulligan Considerations
Commander presents unique mulligan challenges compared to 60-card constructed formats. The format uses 99-card singleton decks (plus the commander in the command zone, totaling 100 cards), which introduces significantly higher variance in opening hands. Because each non-basic-land card appears only once in the deck, the probability of drawing any specific card in the opening seven is roughly 7%, compared to approximately 40% for a four-of in a 60-card deck.
The official mulligan rule in Commander is the same London Mulligan used in all other formats. However, many casual playgroups adopt an unofficial house rule known as the "free mulligan," which allows each player one mulligan with no penalty before the London Mulligan procedure begins. This house rule is not part of the official Commander rules as maintained by the Commander Rules Committee, and it is not used in sanctioned Commander events. Players should confirm with their playgroup whether a free mulligan is in effect before the game begins.
Historically, some Commander groups used the "Partial Paris" mulligan, which allowed players to exile any number of cards from the hand, draw that many minus one, then shuffle the exiled cards back. This rule was deprecated in 2016 in favor of the standard mulligan rules.
When evaluating Commander opening hands, the priorities differ from 60-card formats. The most important elements are:
Lands: A Commander hand should contain three to four lands. The format's higher average mana values and the commander tax (an additional two mana for each subsequent casting from the command zone) make consistent land drops essential through at least turn five. A two-land hand is risky unless it includes mana-positive ramp such as Sol Ring or Mana Crypt.
Ramp: Early mana acceleration is critical in Commander. A hand with three lands and a two-mana ramp spell (such as Arcane Signet, Fellwar Stone, or Nature's Lament) is typically superior to a hand with four lands and no ramp. Ramp allows the player to deploy the commander ahead of schedule and maintain resource parity with the table.
Card draw or card advantage: Because Commander games run longer than 60-card games, the opening hand represents a smaller fraction of the cards a player will see. Keeping a hand that includes a card draw engine or repeatable source of card advantage ensures the player does not run out of resources in the mid-game. Examples include Rhystic Study, Sylvan Library, and Phyrexian Arena.
Color access: Multicolor Commander decks face particular challenges with color fixing. A hand that contains three lands but only one color of mana in a three-color deck may be unable to cast the majority of spells in hand. Prioritize hands that provide access to at least two of the deck's colors, or that include color fixing (Command Tower, fetchlands, signets) to fill gaps.
Frequently Asked Questions
What is the London Mulligan rule?
The London Mulligan is the official mulligan rule for all sanctioned Magic: The Gathering play, adopted in July 2019. When a player chooses to mulligan, that player draws a full hand of seven cards again, then places a number of cards from the hand on the bottom of the library in any order equal to the number of mulligans taken. A first mulligan means drawing seven and putting one back to keep six. A second mulligan means drawing seven and putting two back to keep five. The process may continue until the player decides to keep.
How many lands do I need to consistently keep 7-card hands?
For 60-card constructed decks, most strategies run between 22 and 26 lands. Low-curve aggro decks can function with as few as 20, while control decks often require 26 or 27. For Commander (99-card decks), 35 to 38 lands is the standard range. Use the ScrollVault Mana Base Calculator to determine the optimal count for a specific deck based on its mana curve and color requirements.
What makes a keepable opening hand?
A keepable hand typically satisfies three criteria: the correct number of lands for the deck's curve (usually two to four for 60-card decks), at least one play available in the first two turns, and access to the deck's primary colors of mana. A hand consisting entirely of lands or entirely of spells is almost always a mulligan. Beyond these fundamentals, the decision depends on the deck's archetype and the expected matchup.
How does the simulator work?
The simulator parses the decklist, shuffles it using a Fisher-Yates algorithm, and deals seven cards as the opening hand. Card images are loaded from Scryfall for visual evaluation. The player can keep or mulligan following official London Mulligan rules. A WebAssembly (WASM) engine runs 50,000 simulated hands in the background to calculate mulligan statistics for the specific deck composition, completing all trials in seconds at native browser speed.
Can I simulate Commander/EDH opening hands?
Yes. Select the Commander (99) format option and paste the full 99-card decklist. The simulator handles any deck size and correctly draws 7-card opening hands from the deck. This is particularly useful for testing whether a Commander deck's land count and ramp package produce consistent starts in the singleton format, where variance is inherently higher than in 60-card constructed.
What is the difference between a free mulligan and the London Mulligan?
The "free mulligan" is an unofficial house rule common in casual Commander playgroups. It allows each player to shuffle and draw a new seven-card hand once with no penalty before the standard London Mulligan procedure begins. The London Mulligan is the official tournament rule in which every mulligan costs one card from the player's final hand size. There is no free mulligan in sanctioned play under any format.
How many times should I mulligan?
As a general guideline, going below five cards should be rare. Each mulligan costs one card of resources, which represents a significant disadvantage in both tempo and card advantage. Most six-card hands that contain lands and a reasonable plan for the first few turns should be kept. Mulligan to five only when the six-card hand is genuinely unplayable—for example, zero or one land with a high-curve deck, or no cards that advance the deck's primary game plan.
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