mage.abilities.keyword.SpliceOntoArcaneAbility
702.45. Splice 702.45a Splice is a static ability that functions while a card is in your hand. "Splice onto [subtype] [cost]" means "You may reveal this card from your hand as you cast a [subtype] spell. If you do, copy this card's text box onto that spell and pay [cost] as an additional cost to cast that spell." Paying a card's splice cost follows the rules for paying additional costs in rules 601.2b and 601.2e-g. Example: Since the card with splice remains in the player's hand, it can later be cast normally or spliced onto another spell. It can even be discarded to pay a "discard a card" cost of the spell it's spliced onto. 702.45b You can't choose to use a splice ability if you can't make the required choices (targets, etc.) for that card's instructions. You can't splice any one card onto the same spell more than once. If you're splicing more than one card onto a spell, reveal them all at once and choose the order in which their instructions will be followed. The instructions on the main spell have to be followed first. 702.45c The spell has the characteristics of the main spell, plus the text boxes of each of the spliced cards. The spell doesn't gain any other characteristics (name, mana cost, color, supertypes, card types, subtypes, etc.) of the spliced cards. Text copied onto the spell that refers to a card by name refers to the spell on the stack, not the card from which the text was copied. Example: Glacial Ray is a red card with splice onto Arcane that reads, "Glacial Ray deals 2 damage to target creature or player." Suppose Glacial Ray is spliced onto Reach Through Mists, a blue spell. The spell is still blue, and Reach Through Mists deals the damage. This means that the ability can target a creature with protection from red and deal 2 damage to that creature. 702.45d Choose targets for the added text normally (see rule 601.2c). Note that a spell with one or more targets will be countered if all of its targets are illegal on resolution. 702.45e The spell loses any splice changes once it leaves the stack (for example, when it's countered, it's exiled, or it resolves). Rulings You must reveal all of the cards you intend to splice at the same time. Each individual card can only be spliced once onto a spell. If you have more than one card with the same name in your hand, you may splice both of them onto the spell. A card with a splice ability can't be spliced onto itself because the spell is on the stack (and not in your hand) when you reveal the cards you want to splice onto it. The target for a card that's spliced onto a spell may be the same as the target chosen for the original spell or for another spliced-on card. (A recent change to the targeting rules allows this, but most other cards are unaffected by the change.) If you splice a targeted card onto an untargeted spell, the entire spell will be countered if the target isn't legal when the spell resolves. If you splice an untargeted card onto a targeted spell, the entire spell will be countered if the target isn't legal when the spell resolves. A spell is countered on resolution only if *all* of its targets are illegal (or the spell is countered by an effect).
@author LevelX2