There’s no clean way to template [unexilable], and it doesn’t happen enough that we need a whole keyword.Why can’t you just write “can’t be exiled”

We can, but I believe there are effects you would expect it to stop that it doesn’t.

When I first saw Apex Devastator, I remember seeing the card say Cascade, Cascade, Cascade, Cascade, thinking that had a very clean yet Mythic feeling. When developing a new ability or using an ability in a new way, how do you determine when it's correct to write out the keyword four times versus saying "Cascade four times". In a similar way, how do you decide, for instance, in the case of Gitaxian Spellstalker, whether it should be prowess, prowess, as opposed something like Prowess 2?

Templating has an emotional impact component. While clarity is usually the driving factor, excitement is also important.

Currently every Bestow creature just grants its power/toughness as a bonus and all of its other abilities to the creature it enchants. Why did you not bake that into the keyword itself so that the cards don't have to list everything twice? If it was to keep open flexibility, is there a particular reason that space hasn't been explored since then?

Usually things like this are due to rules issues. I don’t know the specifics on this mechanic.

Is it possible to use the 'Level up' keyword in isolation, without the Leveler card frame and its associated baggage? I.e. A creature with Level up that, in its rules text, attains bonuses referring to the number of Level counters it has.

I’ll say it would be unlikely.

Hello Mr Rosewater,
Un-rules question for you:Modular Monstrosity has the ability, "Whenever an opponent casts a spell, you have five seconds to choose a keyword you haven't chosen for a card named Modular Monstrosity today that's been printed on a creature card."There is also a ruling that reads, "If the keyword has a modifier, such as a mana cost or a number, you must choose a modifier that’s been printed."
My question is, can you choose a keyword that has been printed on a creature with a modifier that's only been printed on a noncreature card. Cumulative Upkeep has appeared on many creatures so is a valid keyword. Can I name "Cumulative Upkeep-Add {R}" which has only been seen on the noncreature Braids of Fire?
Thank you in advance

You have to choose a mechanic and a modifier that’s appeared on a creature.

I would like to say that I find the gift keyword rather hard to read and understand. While I understand that it's supposed to sound more natural, effects like that are simply hard to read with how the game's grammar works for me. I don't really know what can be done to fix that. But I think more gamist language would be helpful in general

We have discovered that real technical language is most helpful to the deeply enfranchised, and a big barrier for those less enfranchised.

Is there a reason Gift wasn't formatted like Ward to remain a generic keyword? It seems like the kind of keyword that could become evergreen if it wasn't specifically tied to hardcoded options like "Gift a tapped fish." For example:Gift - Draw a card (As you cast this spell, you may choose an opponent. If you do, they draw a card before the rest of this spell's effects.)

We can say Gift a _________ a do whatever gift we like. It’s not very restricting.

I am LOVING the simpler designs in Bloomburrow. My favorite card of all time is Vampire Nighthawk so seeing a bunch of creatures with 2-4 evergreen keywords and nothing else makes me happy

Glad to hear that.

I don't like how weird Magic is getting with mechanics lately. Collect evidence, commit a crime, now gift, forage, and pawprints. What happened to just making new keywords and ability words? Has wotc run out of design space?

All of the mechanics you listed, save paw prints, *is* a new keyword or ability word.

"It's so short that I don't know if it needs the keywording."

It's not that shorter than "can't attack" (1 letter less"), and that's Defender. I'm pondering over keywording "can't block" mostly because of it's new frequency of use and it's possible synergies in a similar vein as defender.

Defender got a name because we were moving the ability off the Wall subtype. Also, we like making designs that lose defender, so it’s self referential some of the time. Can’t attack has neither of those two issues.