Notes and Rules Information for Research // Development:

• Only the English version of a Magic card receives Oracle updates and errata. View this card in English. (Scryfall note)
• A card "from outside the game" may be a card from your collection or a card from your sideboard. In tournament play, you can't choose a card from your collection. The cards you choose don't all have to come from the same place. (2009-10-01)
• The exile zone is a part of the game, so you can't get exiled cards. (2009-10-01)
• To cast a split card, choose one of its halves to cast. There's no way to cast both halves of this split card. (2022-12-08)
• Split cards have two card faces on a single card. The characteristics of the half you didn't cast are ignored while the spell is on the stack. (2022-12-08)
• Each split card is a single card. For example, if you discard a split card, you've discarded one card, not two. If an effect counts the number of sorcery cards in your graveyard, Assault // Battery counts once, not twice. (2022-12-08)
• Each split card has two names. If an effect instructs you to choose a card name, you may choose one of those names, but not both. (2022-12-08)

• A split card's characteristics are a combination of its two halves while it is not on the stack. For example, Assault // Battery has a mana value of 5 while it is in your library. If an effect allows you to search your library for a card with mana value 4 or less, you can't find Assault // Battery. (2022-12-08)
• If an effect allows you to cast a spell with certain characteristics, consider only the characteristics of the half you're casting. For example, if an effect allows you to cast a sorcery spell with mana value 2 or less from among cards in your graveyard, you could cast Assault this way, but not Battery. (2022-12-08)
• If you copy a spell that's half of a split card, the copy copies that same half. For example, if you copy Assault, the copy is also Assault, not Battery. (2022-12-08)
• Development's effect is repeated three times no matter which option the opponent chooses. The opponent may choose a different option each time. You'll wind up with three Elemental tokens, two tokens and a card, one token and two cards, or three cards, whichever your opponent chooses. (2006-05-01)
• In a multiplayer game, each opponent, in turn, has the option to let you draw a card. If no opponent does, you put a token onto the battlefield. Then the process repeats two more times. A different opponent may let you draw a card each time. (2006-05-01)