Defining Casual
The thing is that “casual” has no strictly defined meaning in the context of an EDH game that’s laid out by Wizards of the Coast or the Rules Committee... and unlike “competitive,” the players who consider themselves “casual” can’t even agree on what it means. Since there’s such a large variety of definitions of what is and isn’t casual, it’s been quite the nebulous buzzword here on the internet.
Since definitions are so plentiful, I’ll start this rant by giving my definition:
Casual
/adjective/
(in the context of EDH) marked by the desire and willingness to have other decks play some amount of their game-plan before trying to win, especially when noticeable deckbuilding and game-play decisions that help facilitate that desire are made.
This definition has several parts.
Facilitating a Game-plan
So let’s clarify something here: my definition doesn’t intend to HELP opponents achieve their win, it doesn’t involve hugging them, giving them mana, or conceding to create a win… though it may sometimes involve looking the other way. For example: if the Kaalia of the Vast player never gets to attack with Kaalia, they basically don’t get to play their deck (making it a bit of a Lightswitch Deck). Looking the other way to let them get at least one attack in before you murder them to death is something I would mark as a casual decision. Competitively speaking, that Kaalia player COULD have Master of Cruelties to take advantage of your generosity - and I would describe that move as a bit exploitative of the nature of casual.
It bears repeating that at no point do I think a casual player needs to help or give free wins to an opponent; if your opponent sits down with 98 Forests, Lost in the Woods, and Azusa, Lost But Seeking… that’s on them. Instead, it’s about creating an environment where they can reasonably have a shot at winning, and also expect to “play their deck a little” before losing. “Reasonably” is the operative word here, and it introduces a lot bit of subjectivity into the situation. But I never claimed to have an objective definition, a definitive guide, or a defined "power level” for casual.
The Objective Definition, Definitive Guide, and Defined “Power Level” for Casual
Creating a definition like this would be easy, getting other people to agree with it, not so much. Unlike other definitions, the people who adhere to “casual play” don’t necessarily agree on what that means - and, indeed, sitting down at a table of 3 strangers, saying you’re looking for a “casual” game is one of the least meaningful things you can say. Everyone will interpret it differently and you don’t know those people and how they interpret it. I have given you my definition, and my definition is more about mindset than power level.
Therefore, under my definition, a casual mindset can exist at any power level - and what is “reasonable” may change depending on the power level.
In Deckbuilding
So we already gave one example of what casual may look like in gameplay, but let’s talk about what it may look like in deckbuilding. This first notable change is that often times the amount of interaction goes down significantly (though I am a staunch advocate of never going beneath 10 interaction pieces, and often run much more because I’m addicted to the words “in response”). This is simple: the more removal you run, the more you’re denying your opponent the chance to play their strategy or have their deck come together. Running 15 removal spells with the hopes of using one at the right time or responsibly answering something that’s out of hand is one thing…. but running 30 removal spells with the hopes of removing anything and everything that could come your way before it even gets the chance to do so is another thing entirely.
Though it saddens me a bit (because some killspells are so damn cool - I promise I’m working on the counterspell version of that article, bear with me), this leads to a more easygoing feeling game where most players can do a little bit of what they want.
Casual
/adjective/
: feeling or showing little concern : nonchalant
Easygoing
/adjective/
: relaxed and casual in style or manner
(definitions provided by mirriam-webster)
Land Destruction / Stax
Stax and Land Destruction can cause a bit of disruption at casual tables. For me personally, a piece of land destruction here and there to hit problem lands is something I recognize I should have but rarely manage to actually squeeze in (somehow I always cut Ghost Quarter for Witch’s Clinic). Conversely, trying to deny people resources to prevent them from playing is a bit of an antonym to casual.
Soft locks that can be interacted with easily surf the gray area that was previously mentioned in the “reasonably.”
Exploiting the Casual
I mentioned a bit before how Lightswitch Decks and Combos can feel like they exploit the casual player a little bit - after all, a casual player (under my definition), looks at a board where someone hasn’t put many things down and thinks “I should give them space and focus my attention elsewhere because they haven’t actually played anything yet - I’d hate for this game to end before they do something.” Someone who can go from an empty board to a victory with just 3 cards and 7 mana is definitely well-positioned to take advantage of this mindset - they want to see you do something but when that something ends the game there’s a good chance for them to feel gipped or cheated out of a game.
In the End
Your definition may vary… that’s what pre-game talks are for.