Arboria

And this is an uncommon. It's also another one of those Legends "intent trumps sense" cards; basically, if someone didn't play a card, no one can attack him or her. I don't know what that effect has to do with leaping into what's apparently a carnivorous plant. (Come to think of it, the name doesn't make a lot of sense, either. Arbor is the borrowed Latin word for tree; the -ia ending -- and the vocally identical -ea -- has become a shorthand for a setting or place, like a plane or a planet. [Arboria is Latin for black ivy, incidentally.] The word's been used extensively where a connotation of green or growing things is useful. Arboria, then, could be imagined as a plane populated chiefly by plants or plant-like creatures, and that ties in nicely with the picture. ... Now that I really think of it, it's the effect that doesn't make sense; the name and picture seem to match well enough.)

So, first off, we're going to change the name of the card to something more appropriate. My first guess is that the people who named the card meant to call it Arcadia, but found the wrong word. (Arcadia is a Greek province that was famed for its idyllic, rustic life; it was imagined as some kind of Earthbound paradise.) I imagine that the artist did some research on this Arboria word and ended up basing the picture on the Flash Gordon city of the same name -- thus the dangerous plant life. Then the designers married their misnamed vision of Arcadia with the correctly illustrated vision of Arboria. Alternatively, it could simply have been changed at the last moment, as many Magic cards are, or the designers truly thought that a land filled with plants would be the kind of place no one would attack into. I don't know.

Of course, with a new name, we'll need a new picture -- I'm going to use "Les Bergers d’Arcadie" for the art history / tinfoil hat lulz. (Yes, art history people have the lulz now and again.)

Now that all the cringe-inducing stuff is out of the way, let's look at that little type line -- World Enchantment. World enchantments are neat in that they're kinda super-legendary -- only one world enchantment can be in play at a given time, and each (well, most -- Homelands ruined the feng shui) had an effect that affected all players. Only one world enchant can be in play at once; if two are in play at once, the older one is placed in its owner's graveyard. In typical Legends style, there's a caveat -- if the newest world cards are equally young, like they would be if flipped from a Warp World, all the world cards are binned. Now, I like world enchantments -- they're flavorful, and problematic ones can be dealt with by just packing a few of your own. The problem is that they just don't add a lot to the game. In the bulk of games, "world enchantment" could just say "enchantment." Its partner "legendary" is also typically meaningless over the course of a game, but has some immediate payoff: it's easy to understand and it immediately marks the duders it's on as one-of-a-kind badasses. "World" doesn't really make much sense to most people, nor does it have an obvious sense of a one-of-a-kind effect. However, I think it's a fine recurring block mechanic -- having several introduced every three or four years would increase the pool nicely while keeping them relevant in the Standard pools they'd be legal in. Legends has 12, and they're actually nicely priced with a few at good power levels. Having 10-15 such cards in a block feels about right, with the caveat that you need a few interesting ones at the 1-2 mana range to keep the mechanic interesting and varied. (That allows designers to print a few really good ones at the 4+ mana range because every color should have built-in ways to deal with them.) Anyway, as far as nomenclature goes, we're going to keep "world," because "planar" or "omnipresent" don't do a better job, but we will add some reminder text.

This effect shouldn't have been uncommon to begin with, so it's at rare now.  I've kept the functionality more-or-less the same -- it still allows for most activated abilities. There are a few instances where this card is better (under blue Braids, for example) and a few where it's worse (under instants that need to be cast during the opponent's first main phase, for example). I didn't put in any clauses about planeswalkers mostly due to wordiness; there's already an if-then clause, which can be difficult to follow on the first go, and it's inversed and in the negative. (For example, this text would be logically identical: "If a player hasn't played a card since the beginning of her or her last turn, creatures can't attack him or her." Much easier to read, right? We can't put it that way, if my understanding is correct, because that signals a replacement effect. This card doesn't have a replacement effect, it has a generic static effect.)