In most Limited formats, 2-color decks are the norm. But small splashes for a third color can be appealing, especially in multi-color sets like Guilds of Ravnica that are filled with powerful gold cards. To help you decide whether or not to splash in your Sealed or Draft deck, today I have several guidelines and insights.

What is a Splash?

Let’s start by defining some terminology. When I say “splashing,” I mean playing one to four cards of a color. So if you have ten green cards, ten black cards, and three blue cards, then your main colors are green and black, and blue is the splash.

Usually, you’re only splashing one color. Limited decks that splash more than one color are rare and typically require multiple Evolving Wilds.

If you’re running five or more blue cards, then I would say you are playing a full-blown 3-color deck. Such decks are more demanding on the mana base, are often a sign of a draft gone wrong, and I will not consider them today.

How Many Colored Sources Do You Need For a Splash?

As I’ll argue later, a better question to ask instead is “how many lands that only produce the splash color can my deck afford?” Usually, the answer to that question is only one or two. But knowing how consistently you can cast your splash cards is useful too.

A few weeks ago, I wrote an article titled “How Many Colored Mana Sources Do You Need to Consistently Cast Your Spells? A Guilds of Ravnica Update.” Under the assumptions in that article, the following table provides the probability of casting a spell on-curve in a 40-card deck. For each mana cost, the recommended minimum number of sources is highlighted in bolded green.

Suppose you’re splashing blue with only three blue sources. Then, for a 3U spell such as Murmuring Mystic, this table indicates that you are only 66.1% to have drawn an Island by turn 4 on the play if you have drawn at least four lands by that turn after mulligans. Naturally, this consistency number increases as the game progresses, but if you’ve only had a few draw steps to find the blue source, then it’s far from reliable.

Although I can accept splashing one or two powerful spells with only three colored sources in certain slow decks, I would prefer to have four or five. If I deepen the splash to three or four spells, then I need to have four or five sources. That’s just the bare minimum I demand for a splash. And even then, we’re below the number of sources I would recommend to cast spells consistently—with five blue sources, we’re only 85.5% to be able to cast Murmuring Mystic on-curve, assuming we’ve drawn at least four lands. But if the splash card is powerful enough, then that can make up for some colored mana inconsistency.

Given all of these mana base restrictions, which cards make for good splashes? Let’s go over some guidelines.

Splash Only for Cards with a High Converted Mana Cost

Consider a 40-card deck that is splashing red with five red sources. According to the table, you would only be able to cast a 1R spell (such as Ornery Goblin) on-curve 72.8% of the time, but you would be able to cast a 4R spell (such as Command the Storm) on-curve 90.6% of the time.

As a result, early-game creatures are poor cards to splash. There’s a large probability that you won’t be able to cast them at a time where it matters. So you really need to prioritize early drops in your main colors. If you lack them, then that’s one of the few weaknesses that cannot be covered by a splash.

By contrast, spells with a high converted mana cost are excellent splashes because you have more draw steps to find the required colored source. Also, such expensive cards are generally good in the late-game, which means that they are still useful if you didn’t draw your splash color until late.

Splash Only for Single-Colored Cards

Consider a 40-card deck that is splashing black with five black sources. According to the table, you would only be able to cast a 3BB spell (such as Deadly Visit) on-curve 56.2% of the time, but you would be able to cast a 4B spell (such as Douser of Lights) on-curve 90.6% of the time.

Generally speaking, double-colored spells are very poor cards to splash. I basically don’t even consider double-colored spells before I have at least seven or eight sources of that color, and I would greatly prefer to have nine or ten. For a main color, nine or ten sources is doable, but it’s nearly impossible for a splash color.

Splash Only for Removal, Powerful Bombs, or Finishers

Douser of Lights, despite appearing in the previous example, is not a typical splash card. As a replacement-level creature, it is unlikely to be much better than the best alternative big creature from your main colors, so it’s usually not worth destroying your mana base for. There are exceptions where Douser of Lights might cover a “hole” in your deck (for instance when you are drowning in removal but lack finishers to actually close out the game) but most of the time, you want to be splashing for powerful bombs or premium removal spells.

For example, bombs like Aurelia, Exemplar of Justice or Underrealm Lich. Or removal spells like Price of Fame or Conclave Tribunal. Basically, cards you would be happy to first-pick—those are the cards you want to splash. They have to be powerful, they have to be good late, and they have to shore up the weaknesses of your deck.

Splash for Split Cards

Spells that still have some use if you didn’t draw the splash color make for the best splashes. A few years ago, I might have mentioned cards with cycling or cards with morph as examples. But given that Guilds of Ravnica is the most recent set, the split cards are the current example for cards that are perfect on the splash. After all, even if you don’t draw the splash color to cast the non-hybrid part, you can usually still cast the hybrid part to get some value. This way, the card is never dead.

Case in point: the Top 8 of Grand Prix Mexico City. Out of the eight drafters, three chose to splash a color, and three splashed for at least one split card. Mark Jacobson splashed for Find // Finality, Undercity Uprising, and Status // Statue, Steve Rubin splashed for Status // Statue and Severed Strands, and Martin Juza splashed for Response // Resurgence. It’s also worth pointing out that all of them ran three or four sources of their splash color and that none of them ran more than one basic land for their splash color.

Splash Only When it Doesn’t Hurt the Consistency of Your Main Colors

There’s a big difference between splashing green in your Boros deck via four Forest or via two Selesnya Guildgate, one Temple Garden, and one Forest. Even though both land configurations give you four green sources, the latter makes it much more likely that you can retain enough sources for your main colors.

Keeping consistent mana for your main colors shouldn’t be underestimated. For a main color, I generally want to have at least eight colored sources if I merely have a bunch of 2C, 3C, 4C, and/or 4CC spells. If I have C, 1C, and/or 3CC spells, then I’d prefer nine colored sources. And if I have 1CC and/or 2CC spells, then I’d prefer to crank up the number of colored sources to ten. These numbers are easily attainable for 2-color decks, but are difficult to reach when you’re splashing without free fixers.

So splashing is only a good idea when you have mana fixers, preferably ones that don’t cost you a lot. A tapland is a good example. Even a Guildgate in your two main colors helps. For instance, if you’re splashing black in your white-green deck, then the addition of a Selesnya Guildgate allows you to replace a Forest or a Plains with a Swamp.

Avoid Splashes in Aggro Decks or in Decks with Double-Colored Spells

As I explained, I want more colored sources for my main color if I run C, 1C, 1CC, or 2CC spells. This implies that you should avoid splashes in aggro decks and/or in decks with multiple double-colored spells.

If you’re Boros with Trostani Discordant and you’re unable to cast Ornery Goblin or Direct Current in time because you drew a Forest instead of a Mountain, then that’s disastrous, especially when your deck needs to curve out with early drops. You might easily lose more games to colored mana troubles than you might win via your powerful splash card. Leave the splashes to more controlling decks that have few or no double-colored spells.

Avoid 7-7-3 Mana Bases

The mana base with seven basic lands of each of your main colors and three basic lands for your splash color is a classic, but I generally try to avoid it. To see a quantitative example, let’s compare two decks.

Deck A is a 2-color deck containing 21 early-to-mid-game spells and two late-game spells. All spells have a grade 6/10 in terms of power or quality level. With a 9-8 mana base, it can cast an average early-to-mid game spell with 90% consistency and an average late-game spell with 100% consistency. (Numbers are rounded.)

Deck B contains the same 21 early-to-mid-game spells in the two main colors, but it complements them with two late-game bombs on a splash. All early-to-mid-game spells retain their 6/10 grade, but the late-game bombs are all 10s. With a 7-7-3 mana base, it can cast an average early-to-mid game spell with 85% consistency and an average late-game spell with 75% consistency. (Again, numbers are rounded, but they are realistic and based on the table.)

The way I would evaluate splashes would be via the expected consistency-adjusted grade. For the late-game spells, you get a 6 grade 100% of the time in the 2-color deck, but a 10 grade 75% of the time with the splash. In expectation, that’s a 6 versus a 7.5, so splashing is a clear improvement in terms of the late-game spells.

But you also have to take into account the reduction in consistency for the early-to-mid-game spells. The average consistency-adjusted grade used to be 6 * 90% = 5.4, but after weakening the mana base with the splash, this becomes 6 * 85% = 5.1. This may seem small, but it adds up over 21 cards. Indeed, by introducing the splash, the sum of consistency-adjusted grades increased by ( 7.5 – 6 ) * 2 = 3.0 but also decreased by ( 5.4 – 5.1 ) * 21 = 6.3. As a result, we’re worse off overall. This is exactly why I try to avoid the 7-7-3 mana bases.

Conclusion

Ultimately, splashing comes down to the increase in card quality versus the reduction in mana consistency. Regarding card quality, I want to splash for single-color spells that are good in the late game and that are much more powerful than the best alternatives in my main colors. The higher the power differential between the splash cards and the main color alternatives, the more interested I am. If the increase in card quality is slight, then it’s not worth it. But in the quantitative 7-7-3 example, if the alternative spells in our main colors were really bad—say a grade 2/10—then the splash would become valuable enough.

The other aspect is how much the splash hurts your mana base. I generally don’t splash unless I have multiple free fixers like Guildgates. In the quantitative 7-7-3 example, if I could splash off of three on-color Guildgates, then there would be no big objection or downside to the splash. But if I have to run two or more basic lands for my splash color, then I usually opt not to splash, as the reduction in consistency of my two main colors is too harmful. Coupled with my preference to run four or more sources even for a minor splash, I don’t tend to splash a lot in Limited. And if I do, then I pick lands highly.