These cards are common in rarity as well as popularity.

The best way to figure out the theme of a particular color is to look at its common cards. In the case of blue, defensive creatures, counterspells, and card draw make up a large part of it. Based on all the cards available in MTG Arena, here are the 25 best blue commons you can find.

25. Mantle of Tides

What is great about Mantle of Tides:

• It's a cheap source of devotion or artifact count for decks that care about it.
• Using card draw lets you bypass its expensive Equip cost.
• You can use it as a combat trick by using its triggered ability to equip at instant speed.

24. Unwind

What is great about Unwind:

• It's an unconditional counter against any non-creature spells.
• The ability to untap three lands when it resolves makes it cost zero mana in practice.
• Your opponent will be more hesitant to cast more spells for fear of another counter.

23. Slither Blade

What is great about Slither Blade:

• It's a great one-drop for decks like Mono-blue tempo.
• You can leverage its unblockable ability by using auras like Curious Obsession.
• Two toughness lets it survive -1/-1 effects, unlike similar creatures.

22. Teferi's Time Twist

What is great about Teferi's Time Twist:

• You can use it to save a permanent from kill spells or board wipes.
• It works well with permanents that have good enter the battlefield (ETB) abilities.
• You can target anything you control such as lands, also your creatures come back stronger.

21. Hieroglyphic Illumination

What is great about Hieroglyphic Illumination:

• You can cast it at the end of your opponent's turn when you have spare mana.
• It gives you the option to Cycle it in case you can't afford to spend four mana.
• Arena pauses whenever you can Cycle this, so it gives the illusion that you have a cheap spell.

20. Frantic Inventory

What is great about Frantic Inventory:

• It’s excellent in Draft where a deck can exceed four copies of a card.
• When the first copy is used as discard fuel, it still gives value when you cast the others.
• This gets better as the game goes on since you're more likely to draw into more copies.

19. Cartouche of Knowledge

What is great about Cartouche of Knowledge:

• This is a cheap way to add evasion to one of your creatures.
• It gives a small stat boost unlike similar cards like Angelic Gift.
• You are card neutral even if the target dies later because you already got to draw a card.

18. Anticipate

What is great about Anticipate:

• It offers instant speed card selection at a decent mana cost.
• You're not drawing a card so it's not affected by effects like Narset, Parter of Veil's static ability.
• It's often reprinted so it’s a good wildcard investment.

17. Treasure Hunt

What is great about Treasure Hunt:

• You're guaranteed to draw at least one spell on top of all the lands revealed prior.
• It can draw a huge amount of cards with the right kind of deck.
• Using it with cards that order the top of your library lets you rely on something other than luck.

16. Distant Melody

What is great about Distant Melody:

• It can draw a huge amount of cards when used in a tribal deck.
• You can add it as a splash in other decks because it only requires one blue in its mana cost.
• Even with only three cards, it's already superior to other common card draw spells.

15. Devious Cover-Up

What is great about Devious Cover-Up:

• It's an unconditional counterspell that can answer almost any threat.
• Exiling the countered spell guarantees that your opponent can't use them later somehow.
• Having at least two copies lets you loop the contents of your deck if not interrupted.

14. Sea Gate Oracle

What is great about Sea Gate Oracle:

• It gives card selection attached to a solid defensive body.
• You're not drawing a card so it's not affected by effects like Narset, Parter of Veil's static ability.
• Both Human and Wizard creature types are relevant for their respective tribal decks.

13. Cloudkin Seer

What is great about Cloudkin Seer:

• Being a 2/1 flier with card draw makes it a first pick card in Core Set 2020 draft.
• Both Elemental and Wizard creature types are relevant for their corresponding tribal decks.
• You get it for free thanks to Arena's beginner set that’s always legal in Best of One Standard.

12. Into the Roil

What is great about Into the Roil:

• You can target any non-land permanent including your own.
• When cast with Kicker, it's a card neutral way to gain tempo.
• It's very flexible because it has a Kicker ability and almost no target restrictions.

11. Essence Scatter

What is great about Essence Scatter:

• It's an unconditional counterspell that can answer almost any creature.
• You only need to leave two mana open, so your opponent will find it hard to play around.
• Dedicated control decks always want some number of it on their main deck.

10. Omen of the Sea

What is great about Omen of the Sea:

• Scry gives you some card selection before drawing the card.
• It's cheap and can be cast at instant speed when you have free mana.
• Unlike other card draw spells, it's a permanent which can synergize with cards like Yorion.

9. Winged Words

What is great about Winged Words:

• The cost reduction is easy to achieve with the right kind of deck.
• It's a great pick in Draft even as a Divination that can sometimes cost less.
• You already have it in your collection via Arena's beginner set that’s always legal in Best of One.

8. Dive Down

What is great about Dive Down:

• You can use it both as a combat trick or a protection spell.
• It's a staple card for protecting your creature in strategies like Mono-Blue Tempo.
• The cheap one-mana cost makes it easy for you to hold up mana for it.

7. Spell Pierce

What is great about Spell Pierce:

• Having one mana open isn't unusual, so it's easy to catch opponents off-guard.
• Even if your opponent knows you have it, it's still effective if they try too hard to play around it.
• This only costs one-mana, so you're favored to win counter wars when you have it.

6. Unsummon

What is great about Unsummon:

• It lets you get a big tempo swing when used on an expensive creature.
• You can use it in response to a removal spell to save your creature.
• It's always available in Best of One Standard because it's part of Arena's beginner set.

5. Opt

What is great about Opt:

• You can dig up to two cards deep for the card you need with only one mana.
• It's perfect as a cheap enabler for decks that care about instants or non-creature spells.
• This lets you reduce your land count while keeping your land draw probability the same.

4. Quench

What is great about Quench:

• In the early game, it's akin to a hard counterspell because players are casting spells on curve.
• When your opponent knows you have it, it's still effective because they have to play around it.
• It forces awkward turns if you play it when they plan to use their excess mana for other things.

3. Persistent Petitioners

What is great about Persistent Petitioners:

• It's so strong in low power environments that it's often banned in events like Arena Pauper.
• Budget players use this for relevant events since you get an entire deck by crafting four copies.
• Petitioner's 1/3 stat makes it resilient against cheap board wipes like Cry of the Carnarium.

2. Disdainful Stroke

What is great about Disdainful Stroke:

• It's an unconditional counterspell that's a mana efficient answer against expensive threats.
• You can play this to your main deck as a good tempo card in slower metagames or formats.
• It's a great sideboard card for decks splashing blue since it only needs one blue in its mana cost.

1. Negate

What is great about Negate:

• It's an unconditional counterspell that answers almost any non-creature spell.
• You only need to leave two mana open, so your opponent will find it hard to play around.
• Every blue deck will always want some number of it either on their main deck or sideboard.

You may also be interested in:

• The 10 Best MTG: Arena Decks
• MTG Arena Guide, Tips and Tricks
• MTG Arena Best Packs To Buy – A Guide for Beginners and Intermediate Players
• MTG Arena: Best Ways to Get Cards
• Top 15 Best MTG Arena Mythic Rares
• MTG Arena Ranking System Explained
• The Best Singleton Decks in MTG Arena