If The Ringhart Crest is somehow on the battlefield with no choice of creature type, the mana produced by its activated ability can still be spent to cast a legendary creature spell.

In the Commander variant, a double-faced card's color identity is determined by the mana costs and mana symbols in the rules text of both faces combined. If either face has a color indicator or basic land type, those are also considered.

There is a single triangle icon in the top left corner of the front face. There is a double triangle icon in the top left corner of the back face.

To determine whether it is legal to play a modal double-faced card, consider only the characteristics of the face you're playing and ignore the other face's characteristics.

If an effect instructs a player to choose a card name, the name of either face may be chosen. If that effect or a linked ability refers to a spell with the chosen name being cast and/or a land with the chosen name being played, it considers only the chosen name, not the other face's name.

The mana value of a modal double-faced card is based on the characteristics of the face that's being considered. On the stack and battlefield, consider whichever face is up. In all other zones, consider only the front face. This is different than how the mana value of a transforming double-faced card is determined.

If an effect puts a double-faced card onto the battlefield, it enters with its front face up. If that front face can't be put onto the battlefield, it doesn't enter the battlefield.

If an effect allows you to play a land or cast a spell from among a group of cards, you may play or cast a modal double-faced card with any face that fits the criteria of that effect.

Because damage remains marked on creatures until the damage is removed as the turn ends, nonlethal damage dealt to Kolvori may become lethal if you controlled three or more legendary creatures and some of them leave the battlefield that turn.

If an effect allows you to play a specific modal double-faced card, you may cast it as a spell or play it as a land, as determined by which face you choose to play. If an effect allows you to cast (rather than "play") a specific modal double-faced card, you can't play it as a land.

For The Ringhart Crest's first ability, you must choose an existing creature type, such as Fungus or Archer. You can't choose card types (e.g., artifact) or supertypes (e.g., snow).

A modal double-faced card can't be transformed or be put onto the battlefield transformed. Ignore any instruction to transform a modal double-faced card or to put one onto the battlefield transformed.