If you cast an adventurer card as an Adventure, use only its alternative characteristics to determine whether it’s legal to cast that spell. For example, if you control Elsha of the Infinite (“You may cast noncreature spells from the top of your library”) and Keeper of the Crown is on top of your library, you can cast Coronation of the Wilds, but not Keeper of the Crown.

If an object becomes a copy of an object that has an Adventure, the copy also has an Adventure. If it changes zones, it will either cease to exist (if it’s a token) or cease to be a copy (if it’s a nontoken permanent), and so you won’t be able to cast it as an Adventure.

If an effect copies an Adventure spell, that copy is exiled as it resolves. It ceases to exist as a state-based action; it’s not possible to cast the copy as a permanent.

If the target is illegal as Coronation of the Wilds tries to resolve, it won’t resolve and none of its effects will happen. You won’t draw a card, and since it failed to resolve, it will go to your graveyard rather than being exiled. You won’t be able to cast Keeper of the Crown later.

If an adventurer card ends up in exile for any other reason than by exiling itself while resolving, it won’t give you permission to cast it as a permanent spell.

Due to its color indicator (appearing to the left of its type line), Keeper of the Crown is green. Color indicators apply in all zones, not just the battlefield.

A “legendary source” is a permanent, spell, or card in any zone with the supertype “legendary.” Notably, a creature that becomes legendary due to Coronation of the Wilds is a legendary source.

When casting a spell as an Adventure, use the alternative characteristics and ignore all of the card’s normal characteristics. The spell’s color, mana cost, mana value, and so on are determined by only those alternative characteristics. If the spell leaves the stack, it immediately resumes using its normal characteristics.

An effect may refer to a card, spell, or permanent that “has an Adventure.” This refers to a card, spell, or permanent that has an adventurer card’s set of alternative characteristics, even if they’re not being used and even if that card was never cast as an Adventure.

You must still follow any timing restrictions and permissions for the permanent spell you cast from exile. Normally, you’ll be able to cast it only during your main phase while the stack is empty.

Casting a card as an Adventure isn’t casting it for an alternative cost. Effects that allow you to cast a spell for an alternative cost or without paying its mana cost may allow you to apply those to the Adventure.

is a mana symbol. It can be paid with one mana of any type as long as that mana was produced by a legendary source. Keeper of the Crown’s mana value is 3.

If a spell is cast as an Adventure, its controller exiles it instead of putting it into its owner’s graveyard as it resolves. For as long as it remains exiled, that player may cast it as a permanent spell. If an Adventure spell leaves the stack in any way other than resolving (most likely by being countered or by failing to resolve because its targets have all become illegal), that card won’t be exiled and the spell’s controller won’t be able to cast it as a permanent later.

Playtest cards use a modified version of game symbols, such as and . These modified symbols should be treated as the standard symbols during play.

If an effect refers to a card, spell, or permanent that has an Adventure, it won’t find an instant or sorcery spell on the stack that’s been cast as an Adventure.

The effect of Coronation of the Wilds lasts indefinitely. It’ll only expire if the targeted creature leaves the battlefield.

If an effect instructs you to choose a card name, you may choose the alternative Adventure name. Consider only the alternative characteristics to determine whether that is an appropriate name to choose.

Playtest cards aren’t legal for play in any tournament format other than Mystery Booster Limited formats. On the other hand, we expect they will spice up a wide variety of non-tournament games (as long as everyone’s on the same page about using them!).

An adventurer card is a permanent card in every zone except the stack, as well as while on the stack if not cast as an Adventure. Ignore its alternative characteristics in those cases. For example, while it’s in your graveyard, Keeper of the Crown is a green creature card with mana value 3.

For many playtest cards, you’ll need to make a generous assumption that basic game rules would be updated to allow them to work. The Mystery Booster 2 Playtest Card Notes section (reproduced here in individual Gatherer rulings) provides guidance for fitting these cards into the existing rules structure.