fork fling magic the gathering

[Brawl]

fork says:

Instant RR
Copy target instant or sorcery spell, except that the copy is red. You may choose new targets for the copy.

fling says:

Instant 1R
As an additional cost to cast Fling, sacrifice a creature.
Fling deals damage equal to the sacrificed creature's power to target creature or player.

If I fork a fling, do I sacrifice a new creature for the copy?

[seba1983]

no you dont. thats actualy as an example in the comprehensive rules ^^:

706.9. To copy a spell or activated ability means to put a copy of it onto the stack; a copy of a spell isn't cast and a copy of an activated ability isn't activated. A copy of a spell or ability copies both the characteristics of the spell or ability and all decisions made for it, including modes, targets, the value of X, and additional or alternative costs. (See rule 601, "Casting Spells.") Choices that are normally made on resolution are not copied. If an effect of the copy refers to objects used to pay its costs, it uses the objects used to pay the costs of the original spell or ability. A copy of a spell is owned by the player under whose control it was put on the stack. A copy of a spell or ability is controlled by the player under whose control it was put on the stack. A copy of a spell is itself a spell, even though it has no spell card associated with it. A copy of an ability is itself an ability.
Example: A player casts Fork, targeting an Emerald Charm. Fork reads, "Copy target instant or sorcery spell, except that the copy is red. You may choose new targets for the copy." Emerald Charm is a green instant that reads, "Choose one -- Untap target permanent; or destroy target non-Aura enchantment; or target creature loses flying until end of turn." When the Fork resolves, it puts a copy of the Emerald Charm on the stack except the copy is red, not green. The copy has the same mode that was chosen for the original Emerald Charm. It does not necessarily have the same target, but only because Fork allows choosing of new targets.
Example: Fling is an instant that reads, "As an additional cost to cast Fling, sacrifice a creature" and "Fling deals damage equal to the sacrificed creature's power to target creature or player." When determining how much damage a copy of Fling deals, it checks the power of the creature sacrificed to pay for the original Fling.