Deck Construction

Preamble

Because of how flexible and versatile the Doomsday shell is, and how relatively compact the combo can be, there is a lot of potential variance to be found in terms of deck construction. Because of this, combined with individual pilot preferences, metagame shifts, new printings, meta changes and general brewing, it is almost impossible to simply list a default deck to start from and try online or at a local event. If you do wish to find a decklist to start with, consider checking out the #decklists-archive channel in the Doomsday Discord for the most recent successful lists people are trying out.

Because of this, in this chapter instead of presenting just a decklist and explaining the card choices in it, we will instead try to discuss the construction of the deck from the ground up, explore what changing different elements or ratios of card choices can do and hopefully give you an idea of how you might wish to tailor the shell to your own individual playstyle.

We will start by exploring the main card groups which are incorporated into the archetype and then look to explore what considerations are made when putting them together.

Doomsdays

Tutors

The namesake of the deck, Doomsday is a requirement in all variants of the archetype. You will always need to have access to this as a four of in any dedicated build played. As you will need to access and resolve one of these in order to win the game in 99% of cases, often it is advantageous to try and increase the number being played. Because of deck construction rules limitations in Legacy, this means running other cards to try and locate more copies of Doomsday.

The two most common examples are Personal Tutor and Lim-Dul's Vault. Both of these are card disadvantage but allow you to locate a copy of Doomsday and place it on top of your deck. Personal Tutor is more favoured for faster style lists costing only and is good for setting up earlier combo turns whilst LDV is slower but has more flexibility by avoiding Chalice of the Void set to X = 1, being an Instant and being able to tutor for cards other than Sorceries.

Another option, albeit a slower one again is Solve the Equation. This costs but allows you to place the Doomsday, or other target, directly into your hand. It can be favourable for lists that either want access to a more toolbox approach to some of the deckbuilding choices or a slower, more controlling one. There are many other options that could be considered like Burning Wish, Profane Tutor or Spoils of the Vault however the majority of these have been found to not be effective.

Deckbuilding Ratios

In terms of deckbuilding ratios. You should have at a minimum four copies of Doomsday. If you prefer a slower, more control-esque style of play then you don't need to have any more as you should naturally find them through your other cantrips and general desired length of play. If you want a balanced style list then you should look to have around six copies of Doomsday (four Doomsday and two tutors). If you want a faster build then you want to aim for seven to eight copies of Doomsday (four Doomsday and three to four tutors). For faster builds the cheaper mana cost tutors are favourable whilst for slower ones the more expensive may be better options.

If you want to increase the number of copies of Doomsday through the use of tutors, these often replace cantrip slots with numbers of Preordain and numbers of tutors balancing out. This isn't always the case but is the general rule of thumb. You could also consider decreasing interaction as some tutors can act as additional copies of those as well.

Lands

Land Choices

As with the majority of the decks in Legacy, or Magic in general, lands are required in order to be able to cast your spells. Doomsday tends to be a deck centered around the colour pairing with occasionally secondary and tertiary splash colours being integrated in. The deck runs a fetchland manabase normally consisting of four copies of Polluted Delta and four to five additional off-colour fetchlands. The off-colour fetchlands tend to be the based splash ones (where a splash is applicable) as the majority with occasional incorporation of the based splash fetchland.

For example: In a Grixis based Doomsday list you might elect to run four Polluted Delta, three Scalding Tarn and one Bloodstained Mire as your fetchlands of choice.

An eight fetchland configuration is not required with some people opting for running nine with a reduced mana-producing land count. Additionally for more controlling builds, some may elect to replace some of these with copies of Prismatic Vista in conjunction with an increased basic lands count however these are considered not as effective as other fetchlands.

In terms of fetchable lands, Underground Sea is the dominant dual land used. For most straight lists this is a four-of that is run however for less aggressive lists or lists with splash colours in this can often be a three of. Some very aggressive lists which have started to forgo basic lands entirely are option to run four Seas and a copy of Watery Grave as a pseudo fifth copy. In this instance, if no basic lands are being run, the fetchland configuration can be changed to run any combination of /x or /x fetchlands. Diversification is important to avoid Pithing Needle type effects. Conversely, in a more control-based list this can drop down as far as only one or two copies of Underground Sea with an Island dominant manabase being favoured with copies of Urborg, Tomb of Yawgmoth being run as a mana fixer of choice.

If splash colours are being run then it is generally accepted to run one /x dual land of the splash colour and one /x dual land of the splash colour but again you can elect to only run one splash dual with the /X being favoured.

For example: In a BUG based Doomsday list you might elect to run three Underground Seas, one Tropical Island and one Bayou as your dual lands of choice.

The final land type to discuss (for this section) is your basic land count. Traditionally only two to three basics were run normally in a 2-1 ratio of Island to Swamp. More recently though some are opting to run only one of each, some only the Island and others (as mentioned above) are opting to run no basic lands at all. If you want to opt for a more control style build then you will probably need to look to increase your basic land count to four or five. Normally you wouldn't consider running a splash basic such as a mountain or forest however in the heavier control builds it might be worthwhile.

Deckbuilding Ratios

The majority of Doomsday lists like to run between fourteen and seventeen lands as part of their core manabase. The number tends to decrease with a more aggressive playstyle and an increased number of free cycle effects and Lotus Petals. It is normally split as eight fetchlands, two basics and five dual lands with numbers changing based on your preference and playstyle. You can supplement your land count with other toolbox lands like Cavern of Souls or Shelldock Isle however these will be discussed later as part of the Pile Cards section and should not be considered as part of your mana producing land count. Some people also opt to use other toolbox lands like Wasteland in their lists in an effort to be more disruptive. Again this should not factor as part of your mana requirements and instead be considered as interaction.

Let's consider some example mana bases for different styles of play for the deck. We shall present an aggressive, straight Turbo manabase, a more balanced Grixis manabase and a control style Esper manabase.

Turbo

• 2 Polluted Delta
• 2 Flooded Strand
• 2 Scalding Tarn
• 2 Misty Rainforest

• 4 Underground Sea
• 1 Watery Grave
• 1 Island

If you were to run a splash colour you could replace the Island with the /x dual land of the appropriate type here.

Balanced

• 4 Polluted Delta
• 3 Scalding Tarn
• 1 Bloodstained Mire

• 3 Underground Sea
• 1 Volcanic Island
• 1 Badlands
• 1 Island
• 1 Swamp

You can consider swapping basics for additional fetchlands if you want to be a little less resilient vs. Wasteland or Blood Moon effects. Inversely you can also go down to three Seas to add an additional basic land if desired.

Control

• 4 Polluted Delta
• 4 Flooded Strand

• 2 Underground Sea
• 1 Tundra
• 1 Scrubland
• 1 Plains
• 2 Island
• 1 Swamp
• 1 Urborg, Tomb of Yawgmoth

Once again you can play around with numbers of different fetchlands, duals and basics to find a ratio that fits your playing style preferences.

Mana Acceleration

Accelerant Choices

Because Legacy can be a very fast and efficient format, additional help is needed in order to facilitate casting a spell which costs . One advantage of the deck is the speed with which you can deploy a Doomsday to the stack, hopefully outracing any pressure that is on the board or avoiding your opponent being able to obtain interaction in hand or the mana resources to use it. To facilitate this we use a few cards that temporarily accelerate our mana.

The core ones played are Dark Ritual and Lotus Petal. Dark Ritual is a key tool which conveniently, on resolution, produces the exact mana required to cast Doomsday. It allows you to be able to aggressively fetch basic Islands and still have and it can even enable you to cast Doomsday on turn one of the game. You should almost always be running four copies of Dark Ritual.

Lotus Petal is both a mana accelerant that helps cast your spells and can be easily incorporated effectively in your piles. It helps fix your mana to enable you to pivot from cantripping to casting Doomsday and can also facilitate a turn one or turn two Doomsday though not as effectively as Dark Ritual does. The number of Lotus Petals increase as number of lands decreases and higher counts are favourable for either decks looking to win fast or that have greedier mana requirements due to splash colours. In a control style list you may only wish to run two whilst most other lists will probably wish to run three or four.

Some people opt for additional acceleration in the form of Cabal Ritual. This is simply a way to ensure you have more consistent access to and is generally just a way to jump from two mana to three mana. The Threshold effect is normally not something that is required. You would want to run Cabal Ritual if you really wanted to cheat on mana and try to make your deck as consistent as possible for mulliganing purposes or to enable aggressive searching of basic lands more frequently. If running alternate plans that can make use of the mana such as Grief or Sheoldred, the Apocalypse you can also use them to power these out quicker.

Deckbuilding Ratios

As Dark Ritual is pretty much a core staple, the only consideration to changing ratios tends to be around the number of Lotus Petals run. If you are on fifteen or less mana producing lands then you should very much consider running the full four. At sixteen to seventeen you can consider running maybe three and at eighteen you should probably be running two at most. You should always consider running at least two because of the usefulness in pile building such as in the example below:

+ Cantrip

Interaction

Under interaction, there are two additional sub-categories of cards. Proactive and reactive. Proactive interaction is one you can use at any time to try and either interfere with your opponent's game plan or to protect your own. Examples of this include discard spells like Duress. Reactive interaction are cards that rely on your opponent making an action before they can be used. Examples of this include counter-magic like Spell Pierce.

Proactive Interaction

Proactive interaction is most commonly found in Doomsday lists as either discard effects such as Duress and Thoughtseize or tools like Teferi, Time Raveler. They are generally useful in every matchup but can be considered slow as they normally cost mana and are at Sorcery speed meaning they will not help prevent turn one plays when on the draw.

Discard effects are good at providing information about a matchup early on and either preventing your opponent landing relevant threats or taking away their own interaction from them. They tend to excel in based fair matchups or against opposing combo decks. They are often weaker against fair non- decks or stompy type shells. The main limitation of discard effects is that, if they are used on a turn prior to the combo turn, the opponent may have a chance to draw into what they need.

Almost all styles of Doomsday list will run some number of discard effects, normally splitting between Duress and Thoughtseize and ranging between two and five copies. The ratio of the split normally favours Duress due to the impact of the life loss from Thoughtseize and the bias of non-creature spells being more impactful in matchups however this is meta-dependant and sometimes it is better to favour Thoughtseize. You should always include at least one of each in order to be able to incorporate the appropriate one in pile building. Some have tried alternatives like Cabal Therapy and Inquisition of Kozilek however they have been found to be not as effective as Duress and Thoughtseize.

Teferi is a very strong tool in the Doomsday arsenal. It prevents almost all interaction during your combo turn and allows you to easily deploy your threats whilst disrupting theirs with minimal fear of reprisal. It also has the handy ability to act as slow card advantage and removal for troublesome permanents with the -3 ability. The main weaknesses of Teferi include the fact that it is a three mana spell which means it can be slow to be deployed. It is also removable once down through opposing cards like Abrupt Decay and requires you to be splashing into . Because of this Teferi is not favoured outside of slower, more controlling lists in general.

If running Teferi, it will normally be as a one to two of in the deck and will be run alongside discard effects and other reactive disruption.

There is one more main class of proactive disruption in the form of running a creature package. The most commonly found card for this is Baleful Strix however other options like Uro, Titan of Nature's Wrath and Sedgemoor Witch have been tried. The idea behind these is they act as delays to your opponent's pressure whilst also providing additional card draws. Uro and Sedgemoor both also provide an alternative way to win without casting Doomsday for matchups where that may be useful.

If running Strixes, these normally are swapped out for some mix of free cycle effects, Daze or Preordains. Adding some of the other creature packages are less simple to map out but can also take the place of those slots alongside Lotus Petals. Strixes are normally run as a two to four of and creature plans like Uro a three to four of (where incorporated).

The final proactive interaction that can be run is some combination of Wasteland and Stifle. Some use this as a way to actively disrupt their opponent's manabase, much in the same vein that a tempo deck like Delver would, and use that to accrue pseudo card advantage and prevent your opponent from being able to interact with their resources. When run they are normally a compact package never more than in a 3-3 split, normally around 2-2. They tend to be run with faster to more balanced builds rather than slower ones and they take the slots from free cycle effects and other interaction.

Reactive Interaction

Reactive interaction is most commonly found in Doomsday lists as either counterspell effects such as Force of Will and Daze or tools like Veil of Summer. They are effective at efficiently interacting with your opponent's cards and can help in both offense and defense. These tend to be more mana efficient than the proactive interaction available.

Countermagic is the most common form of interaction found in Doomsday. As with many blue decks in Legacy, the first card to consider is Force of Will. Force allows for interaction from turn one, even without lands in play, and provides a catch-all answer to anything your opponent is trying to do. It also can be used to help push through your own combo turn. As the Doomsday shell is predominantly a heavy deck, the cost can almost always be paid. Force of Will is almost always run as a four of and should be considered a core staple of the deck.

Daze is another excellent tool in terms of interaction. It provides a second, mana-efficient piece of interaction that can help defend against key tap-out threats like Trinisphere or Sylvan Library whilst also providing the ability to push through early Doomsdays. As the game progresses they start being less effective but can be used pitch to Force of Will meaning they are never truly dead cards. For non-control based lists this is almost always a four-of include into the deck as it really helps push through a lot of matchups. In control lists it tends to not be included at all, instead being replace with alternative tools like Baleful Strix and Teferi.

There are a couple of additional counter spell effects you can elect to run but these are normally personal preference choices. Flusterstorm and Spell Pierce are both viable options with the former being good at protecting your combo and against opposing combo and the latter being better at protecting from permanent hate like Blood Moon or planeswalkers like Karn the Great Creator. These normally contend with the proactive interaction slots and are only ever featured as a one or two-of at most. Some will also elect to run some number of Pact of Negation however this will be discussed as a pile card.

Veil of Summer is an interesting interaction card. It can act both as proactive interaction by initiating a combo turn with it, but can also act as reactive interaction as part of a counter war or defending against opposing discard effects or similar. We have elected to include it as reactive interaction because the most common usage is in a reactive sense over a proactive sense. It is very effective against opposing or based decks however it has almost no text in non- matchups and thus is normally relegated to the sideboard. If it is run in the main it tends to replace some number of discard spells and is only run as a two to three-of.

Deckbuilding Ratios

When combining the two interaction types, most lists will have around a total of eleven to thirteen interaction slots in them. These tend to be split into eight to ten reactive slots and anywhere between two and eight proactive slots depending on the style of the list being played. As mentioned, almost all lists will have at a minimum four copies of Force of Will and at least one Duress and one Thoughtseize. The rest becomes quite flexible.

Let's consider some example mana bases for different styles of play for the deck. We shall present an aggressive, Grixis Turbo package, a more balanced straight package and an Uro style BUG package.

Turbo

• 4 Force of Will
• 4 Daze
• 2 Thoughtseize
• 1 Duress

A no-nonsense approach, this list would likely run a heavy number of free cycle effects and a low number of lands. As a result it is relying on being able to go fast and not need to worry about having a lot of interaction, only enough to try and push through an early combo. It would also likely be supplemented by a Pact of Negation too.

Balanced

• 4 Force of Will
• 4 Daze
• 2 Thoughtseize
• 3 Duress
• 1 Flusterstorm

Here you can see this list has opted to run a heavier discard package and some additional countermagic. They have a higher land count than the turbo list and likely fewer free cycle effects too which provides the slots to add these additional interaction elements in.

Uro

• 4 Force of Will
• 3 Daze
• 1 Thoughtseize
• 2 Duress
• 4 Baleful Strix
• 3 Uro, Titan of Nature's Wrath

This list has invested in having the alternate gameplan as part of it's construction. Free cycle effects and Lotus Petals will probably both be very low, land count will likely be high and you can see they have trimmed on a Daze here too. This list will still be able to win fast but is expecting to have a longer and grindier game most likely.

Cantrips

Cantrip Choices

Cantrips are a staple in decks in Legacy and provide the ability to find the cards you need at the time you need them and allow you to cheat on mana resources as you don't have to rely on the top of your deck or openening hand to draw them. I won't write too much in detail on the different cantrips used however if you wish to read more about the ways of using them in the deck, feel free to read this article here.

There are two core cantrips which are run as a core part of the deck package; Brainstorm and Ponder. These are both run as four-ofs and, without very good justification, should likely never drop below that number. Preordain is a more flexible cantrip, normally being run as at least a two-of but anywhere up to a four-of most of the time. As said before the number of Preordains tends to fluctuate with the style of the deck often being cut in favour of tutor effects or creature packages.

Mishra's Bauble is a card that generally only gets played in slower builds alongside high numbers of Predict. It acts as a delayed way to draw into a pile as well as providing fetching information for either your own deck or in terms of what your opponent is playing. Most importantly though it allows you to consistently hit with Predict allowing the maximum card advantage to be accrued with it. Outside of this interaction though, it is likely worse than Preordain despite the lower cost as it decreases your potential blue count for Force of Will and the delayed draw cannot contribute to same turn wins when you need them.

Consider is a new card from 2021 which has started to be incorporated into lists. It acts like a cantrip however it is more accurate to describe it as a pile card more than anything. If being run, it will be between 1 and 2 copies normally replacing some number of Preordain.

Deckbuilding Ratios

Besides free cycle effects and other pile cards like Consider and Predict, lists generally run the usual playsets of Brainstorm and Ponder. Preordain may or may not join the party depending on the amount of slots dedicated to permission and tutor effect in the list. If you are unsure on what style of list you wish to play it is likely better to run the full twelve cantrips and then work out what you wish to replace them with at a later point in testing.

Pile Cards

This is probably the most diverse set of cards and might as well be titled miscellaneous however there are some important pieces in here that are fundamental to the deck. A lot of these cards do have a lot of usage outside of the Doomsday pile but the reason they are in the deck is often to be searched up and utilised as part of your combo. Examples like Echo can be used to build piles that have backup plan or maximise the cards you obtain in them whilst cards like Relic can be use to protect your graveyard against Endurance. In theory almost all of these are optional extras apart from one key component: Thassa's Oracle.

Thassa's Oracle

Thassa's Oracle is the card you need to be able to win the game, (unless you have a plan B) and therefore you have to run at least one of them. Some people like to run two but the second is often relegated to the sideboard. There is not much else to say other than the alternatives in Laboratory Maniac and Jace, Wielder of Mysteries unfortunately do not display quite the same efficiency or efficacy as a win condition of choice.

Free Cycle Effects

The next set of pile cards to look at are the free cyclers, that is Street Wraith and Edge of Autumn. In pile building they provide a free way to draw a card that cannot be countered through conventional means. This gives a lot of flexibility and enables a lot of the faster, or same turn pile wins. Both tend to be run because sometimes the life total can be pressured and you may not have the two life available to cycle a Street Wraith, even though it is probably the more useful of the two outside of the combo.

Depending on your playstyle you can probably run between one and six of these effects. You will want at least one to be able to create Brainstorm piles that use LED and a free cycle effect but after that it's up to personal taste. Most turbo lists will run four to six. Normally one Edge and the rest Wraiths. Balanced lists will run two to five, again with at least one Edge and finally control or slower lists might only run zero to two. If they are just running one it is likely just a Street Wraith.

Multi-Draw Spells

There are a few options for this category but they all do very similar things. Ideas Unbound, Predict and Night's Whisper all allow you to access multiple cards in your pile at once. They also can have additional utility outside of the combo with Predict and Whisper providing stable card advantage over time. Ideas Unbound is the most effective and popular one with the others sometimes providing a supporting role. Most of the time however only one multi-draw spell is run in a list. Control style lists may consider to run multiple Predict either with, or without, and Ideas Unbound in the list as a raw card advantage engine.

Lion's Eye Diamond

Lion's Eye Diamond is an incredibly strong card that allows you, in your piles, to cheat on mana. It has some limitations in not allowing you to use countermagic to protect anything you cast with it but the benefits are so large that these are not a concern. It is one of the cards that enables the fastest wins and the most mana efficient piles in the deck. You should almost always run one as a core card in the deck however any more can be a liability as it has almost no use outside of piles (though there are some corner cases).

Cavern of Souls

Cavern of Souls is an excellent way to ensure you can resolve Oracle in the face of countermagic or a Chalice of the Void X = 2. It fits very neatly into the shell and can be incorporated into many of the piles that are made. Lists will run between zero and one of them, sometimes in the sideboard but mostly in the main deck. Although it can tap for it is not considered to be counted towards your land count and should instead be considered as a spell. It can have some extra utility if you are running a creature package by allowing you to cast those creatures with it. Good in heavy metas.

Pact of Negation

Pact of Negation is similar to Cavern in providing a mana efficient way to protect your Oracle resolving however it has the added benefit of also stopping effects like Stifle or Endurance from being used. If winning in the same turn as you cast Doomsday you can also use it to help resolve the Doomsday in the first place and, in a pinch, it can be used defensively too though this is certainly not the optimal use of it. If it is run it is normally a single copy which can be in the main or side however some do like running more if they want to be more aggressive and draw it naturally.

Consider Package

As mentioned above in the cantrip section. Consider is a useful tool that can enable some unique piles and help fortify existing ones. If running Consider, it may optionally be paired with Deep Analysis which enables very mana-efficient piles. Some elect to run this package over Ideas Unbound whilst others prefer to run them in conjunction with one another. If running the package, the Consider normally replaces a Preordain and the Deep Analysis replaces a Personal Tutor or a free cycle effect. If planning to go fast it is best to maximise the number of free cycle effects with Consider and Deep Analysis as they also enable the ability to go for aggressive, low resource wins.

Putting It All Together

Now that we've seen all the components we need to work out how we want to fit them into our list. We need to consider a few things before we start building to work out how we want it to look.

Think about the following questions:

• What turn do we want to cast Doomsday on?
• How often do we want to make pass-the-turn piles?
• What part of the meta do we want to beat?
• What part of the meta do we want to avoid?
• Do we always want to ensure we are protected or are we happy to blindly jam at any given opportunity?
• What tools do we want access to in the sideboard?

If we want to cast Doomsday early then we want to maximise our cheap tutors and number of mana accelerants and/or free cycle effects but will likely have to reduce the number of lands and cantrips we run. We also probably want to include Cavern and Ideas Unbound to enable to most efficient PTT piles and Consider with Deep Analysis to provide the most mana efficient wins available to us. If we want to pass the turn more we probably want a lower free cycle count and would probably not run Pact of Negation. If we wanted to win on the same turn we cast Doomsday more often we would probably maximise the use of both of these.

These are just a few things to have in mind when putting your decklist together. As stated at the start of the chapter, it's not useful to present a default decklist because there is no such thing. It's best to follow the principles here, construct a list and test, test, test. Tinker with what you can and really try to understand the purpose of running each card in your deck. That way if anyone questions why you run a certain configuration you will be able to provide the justification of each choice you make.

If you don't feel up to it or maybe don't have the luxury of time to be able to follow this exercise then there are many examples of proven lists on websites like TCDecks or that can be found in the #decklists-archive channel in the Doomsday Discord.

Next Steps

Now you have considered how to build your main deck, next chapter will explore the principles behind sideboard card choices and the ideas to follow for facing off against different archetypes.