<a class="edhrecp__link-a" content="Underworld Breach" href="#" target="_blank">Underworld Breach</a> | Art by <a href="https://www.liesetiawan.com/" target="_blank" rel="noopener">Lie Setiawan</a>
Just like any other game of Magic, a game of cEDH has to end. Unlike just about every other game, however, the vast majority of cEDH games end not with the slow deluge of combat damage, but with a single explosive turn as the victor executes a combo package.
Some decks have unique commander-dependent payoffs, others use niche, strategy-specific exploits, but regardless of whichever commander helms your cEDH deck, odds are that your deck will still be playing at least one of the all-time greats: the compact, resilient, cheap, flexible combos that form the heart of cEDH.
So, what are they, and how do they work? This guide has your answers.

Competitive Commander is brimming with niche, deck-specific combos that can propel otherwise okay commanders to stardom. While important to the health and the diversity of the format, those are not what we'll be focusing on for this guide.
Instead, we first need to understand the fundamentals - the core combos of cEDH.
<div class="edhrecp__cards"><div class="edhrecp__card-container" name="Channel"></div><div class="edhrecp__card-container" name="Fireball"></div></div>
Magic's very first combo.
The combos that follow are all cheap, commander-independent, and compact. Many of them are layered, with some number of the requisite cards being swappable for other alternatives (e.g., <a class="edhrecp__link-a" content="Lion&#039;s Eye Diamond" href="#" target="_blank">Lion&#039;s Eye Diamond</a> for <a class="edhrecp__link-a" content="Lotus Petal" href="#" target="_blank">Lotus Petal</a>, as a bit of a preview).
To top it all off, the average card quality is quite high; some of these combos are so good that it wouldn't be surprising for a new cEDH player to accidentally assemble them simply because they'd already be running everything each package needed.
All in all, these combos stand head and shoulders above the rest because they just don't need that much investment. Mana, cards, card quality - very little is sacrificed to play these.

Odds are, even if you don't already play cEDH, this is the first combo that comes to mind when asked about how the average cEDH game ends.
<div class="edhrecp__cards"><div class="edhrecp__card-container" name="Thassa&#039;s Oracle"></div><div class="edhrecp__card-container" name="Tainted Pact"></div><div class="edhrecp__card-container" name="Demonic Consultation"></div></div>
And, wouldn't you know it, you'd be pretty spot-on. For as little as spread across two spells, the game can be yours. Here's how:
<ul>
<li>Cast <a class="edhrecp__link-a" content="Thassa&#039;s Oracle" href="#" target="_blank">Thassa&#039;s Oracle</a> for . It'll resolve and put its enters trigger onto the stack.</li>
<li>In response to the enters trigger, cast either <a class="edhrecp__link-a" content="Tainted Pact" href="#" target="_blank">Tainted Pact</a> or <a class="edhrecp__link-a" content="Demonic Consultation" href="#" target="_blank">Demonic Consultation</a>. Regardless of which card you cast, resolve it such that you exile your entire library.
<ul>
<li>Demonic Consultation works in any deck, as you'll simply name a card not in your deck when the spell resolves.</li>
<li>Tainted Pact, meanwhile, requires that your deck doesn't run any duplicate cards (that is, no duplicate basic lands), as the spell will stop exiling cards once it hits a duplicate.</li>
</ul>
</li>
<li>Now that you don't have a deck, resolve the enters trigger. Thassa's Oracle's triggered ability will see that you have fewer cards (or at most, as many) in your library than you have devotion to blue, and as such you'll win the game.</li>
</ul>
Tainted Fish, as this combo is often known, is one of the fastest combos out there, requiring only one truly bad card (Thassa's Oracle) and either one of two decently-playable instant-speed tutors to win the game.

Next up, we have the most modular combo in cEDH, one which really only requires the namesake card plus any way to go at least mana and card neutral as you repeatedly escape a storm pile.
<div class="edhrecp__cards"><div class="edhrecp__card-container" name="Underworld Breach"></div><div class="edhrecp__card-container" name="Lion&#039;s Eye Diamond"></div><div class="edhrecp__card-container" name="Brain Freeze"></div></div>
Starting off with <a class="edhrecp__link-a" content="Underworld Breach" href="#" target="_blank">Underworld Breach</a> itself, this card is an enchantment for that grants each spell in your graveyard an escape cost equal to that card's mana cost, plus exiling three cards from your graveyard. Additionally, Underworld Breach has a triggered ability which requires that its controller sacrifice it at the beginning of the end step.
A keen eye will see where this card immediately breaks things: if you can go mana-positive (or at least mana neutral) with a spell, such as a ritual, a cracked <a class="edhrecp__link-a" content="Lotus Petal" href="#" target="_blank">Lotus Petal</a>, or a tapped-and-somehow-sacrificed <a class="edhrecp__link-a" content="Mox Opal" href="#" target="_blank">Mox Opal</a>, Underworld Breach quickly turns into a card that powers out an arbitrarily high storm count for just that initial mana investment.
Pair whatever mana source you find with a way to repeatedly mill yourself, either classically via <a class="edhrecp__link-a" content="Brain Freeze" href="#" target="_blank">Brain Freeze</a> or through drawing-and-discarding a la <a class="edhrecp__link-a" content="Wheel of Fortune" href="#" target="_blank">Wheel of Fortune</a>, and you've got yourself an empty deck!
This flexibility and cost efficiency is what makes Underworld Breach so potent. While the average package is bigger than that of Tainted Fish, at three cards instead of just two (Underworld Breach, the mana source, and the escape-fodder source), the flexibility is simply insurmountable.

Our next combo is another flexible package depending on a central card coupled with any of a plethora of secondary spells, and that is the Valley Floodcaller infinite-mana combo.
<div class="edhrecp__cards"><div class="edhrecp__card-container" name="Valley Floodcaller"></div><div class="edhrecp__card-container" name="Retraction Helix"></div><div class="edhrecp__card-container" name="Banishing Knack"></div></div>
<a class="edhrecp__link-a" content="Valley Floodcaller" href="#" target="_blank">Valley Floodcaller</a> is a 2/2 Otter Wizard for with flash that lets you cast all of your noncreature spells as though they had flash. And whenever you cast a noncreature spell you get to untap all your Birds, Frogs, Otters, and Rats. They get +1/+1 until end of turn.
Outside of being a <a class="edhrecp__link-a" content="Necropotence" href="#" target="_blank">Necropotence</a> all-star thanks to that flash-enabler effect, Valley Floodcaller pulls double duty as a combo piece when paired with either <a class="edhrecp__link-a" content="Retraction Helix" href="#" target="_blank">Retraction Helix</a> or <a class="edhrecp__link-a" content="Banishing Knack" href="#" target="_blank">Banishing Knack</a>, as well as any mana-positive mana rock (or, in cases where you control a mana-producing creature of a type that Valley Floodcaller untaps, then even a mana-neutral rock will do it).
Here's how it works:
<ul>
<li>If Valley Floodcaller is not summoning sick, target it with either Retraction Helix or Banishing Knack. If it is summoning sick, then either wait until it isn't or target a non-summoning-sick creature you control which is of one of the untapping types (Bird, Frog, etc.).</li>
<li>After your Helix/Knack has resolved, proceed to tap the creature it targeted in order to return a mana-positive mana rock you control to your hand. If that rock is untapped, tap it for mana before returning it.</li>
<li>Now recast the rock. Valley Floodcaller will trigger, untapping the relevant Helix/Knack creature.</li>
<li>Tap the newly resolved rock for mana, then retap the Helix/Knack creature to return the rock.</li>
<li>Rinse and repeat for infinite mana, as well as an infinite +X/+X boost to creatures of the untapping types.</li>
</ul>

Finally, we come to our last of the core combos and the second strictly infinte-mana producing one: the pair of <a class="edhrecp__link-a" content="Devoted Druid" href="#" target="_blank">Devoted Druid</a> and either <a class="edhrecp__link-a" content="Swift Reconfiguration" href="#" target="_blank">Swift Reconfiguration</a> or <a class="edhrecp__link-a" content="Hazel&#039;s Brewmaster" href="#" target="_blank">Hazel&#039;s Brewmaster</a>.
<div class="edhrecp__cards"><div class="edhrecp__card-container" name="Devoted Druid"></div><div class="edhrecp__card-container" name="Swift Reconfiguration"></div><div class="edhrecp__card-container" name="Hazel&#039;s Brewmaster"></div></div>
Forming the core is Devoted Druid, a 0/2 Elf Druid for with two abilities: ": Add ," and "Put a -1/-1 counter on this creature: Untap this creature."
Forming the support are two cards that each have a way of giving a noncreature permanent both of these abilities.
Swift Reconfiguration is an Aura for with flash that turns enchanted creature (or Vehicle) into a Vehicle artifact with crew 5, causing the enchanted permanent to lose all other card types in the process.
Hazel's Brewmaster, meanwhile, is a 3/4 Squirrel Warlock for that, when it enters, exiles up to one target card from a graveyard and creates a Food token. Plus, it grants all Food you control all activated abilities of creature cards exiled by the Brewmaster.
Regardless of which path you choose to get there, either of these two cards puts you in essentially the same state: with a noncreature artifact that has the ability to tap for and to put a -1/-1 counter on itself in order to untap it. Since the artifact isn't a creature, you can tap and untap it this way with as many -1/-1 counters as you like, racking up infinite in the process.

best commander combos

EDHREC Guide To Combos in cEDH