Split Decision — ruling 1

If duplication gets more votes, Split Decision creates a copy of the spell. You control the copy. That copy is created on the stack, so it's not "cast." Abilities that trigger when a player casts a spell won't trigger. The copy will resolve like a normal spell, after players get a chance to cast spells and activate abilities.

Split Decision — ruling 2

The copy will have the same targets as the spell it's copying unless you choose new ones. You may change any number of the targets, including all of them or none of them. If, for one of the targets, you can't choose a new legal target, then it remains unchanged (even if the current target is illegal).

Split Decision — ruling 3

If the spell being copied is modal (that is, it says "Choose one —" or the like), the copy will have the same mode. You can't choose a different one.

Split Decision — ruling 4

If the spell being copied has an X whose value was determined as it was cast (like Skeletal Scrying has), the copy will have the same value of X.

Split Decision — ruling 5

Effects based on any additional costs that were paid for the original spell will be copied as though those same costs were paid for the copy. For example, if a player exiles three cards from their graveyard to cast Skeletal Scrying, and you copy it, the copy will also cause you to draw three cards and lose 3 life (but you won't exile any cards from your graveyard).

Split Decision — ruling 6

Because the votes are cast in turn order, each player will know the votes of players who voted beforehand.

Split Decision — ruling 7

You must vote for one of the available options. You can't abstain.

Split Decision — ruling 8

No player votes until the spell or ability resolves. Any responses to that spell or ability must be made without knowing the outcome of the vote.

Split Decision : règles, fonctionnement et interactions (MTG)

Split Decision is one of those cards players keep asking about. Here is, in plain words, what its official text says, the rulings published by Wizards of the Coast, and the combos players actually run.

Official card text

Will of the council — Choose target instant or sorcery spell. Starting with you, each player votes for denial or duplication. If denial gets more votes, counter the spell. If duplication gets more votes or the vote is tied, copy the spell. You may choose new targets for the copy.

How it works : Split Decision

Original English text — Wizards of the Coast / Scryfall

#1May 29, 2014· Wizards of the Coast
If duplication gets more votes, Split Decision creates a copy of the spell. You control the copy. That copy is created on the stack, so it's not "cast." Abilities that trigger when a player casts a spell won't trigger. The copy will resolve like a normal spell, after players get a chance to cast spells and activate abilities.
No other card is named in this ruling.
#2May 29, 2014· Wizards of the Coast
The copy will have the same targets as the spell it's copying unless you choose new ones. You may change any number of the targets, including all of them or none of them. If, for one of the targets, you can't choose a new legal target, then it remains unchanged (even if the current target is illegal).
No other card is named in this ruling.
#3May 29, 2014· Wizards of the Coast
If the spell being copied is modal (that is, it says "Choose one —" or the like), the copy will have the same mode. You can't choose a different one.
No other card is named in this ruling.
#4May 29, 2014· Wizards of the Coast
If the spell being copied has an X whose value was determined as it was cast (like Skeletal Scrying has), the copy will have the same value of X.
No other card is named in this ruling.
#5May 29, 2014· Wizards of the Coast
Effects based on any additional costs that were paid for the original spell will be copied as though those same costs were paid for the copy. For example, if a player exiles three cards from their graveyard to cast Skeletal Scrying, and you copy it, the copy will also cause you to draw three cards and lose 3 life (but you won't exile any cards from your graveyard).
No other card is named in this ruling.
#6May 29, 2014· Wizards of the Coast
Because the votes are cast in turn order, each player will know the votes of players who voted beforehand.
No other card is named in this ruling.
#7May 29, 2014· Wizards of the Coast
You must vote for one of the available options. You can't abstain.
No other card is named in this ruling.
#8May 29, 2014· Wizards of the Coast
No player votes until the spell or ability resolves. Any responses to that spell or ability must be made without knowing the outcome of the vote.
No other card is named in this ruling.
#9May 29, 2014· Wizards of the Coast
Players can't do anything after they finish voting but before the spell or ability that included the vote finishes resolving.
No other card is named in this ruling.
#10May 29, 2014· Wizards of the Coast
The phrase "the vote is tied" refers only to when there is more than one choice that received the most votes. For example, if a 5-player vote from among three different choices ends 3 votes to 1 vote to 1 vote, the vote isn't tied.
No other card is named in this ruling.