2011-01-22 : All the copies are created on the stack, so none of them are cast. Abilities that trigger when a player casts a spell won’t trigger. The copies will then resolve as normal, after players get a chance to cast spells and activate abilities.

2011-01-22 : Each copy will have the same targets as the spell it’s copying unless its controller chooses new ones. That player may change any number of the targets, including all of them or none of them. If, for one of the targets, that player can’t choose a new legal target, then it remains unchanged (even if the current target is illegal).

2011-01-22 : If the original spell has an X whose value was determined as it was cast, each copy has the same value of X.

2011-01-22 : If the original spell is modal (that is, it says “Choose one —” or the like), each copy will have the same mode(s). You can’t choose different ones.

2011-01-22 : When the triggered ability resolves, it creates a copy of that spell for each other player. The active player creates their copy and may choose new targets first (if that player isn’t the enchanted player), then each other player (except the enchanted player) creates their copy and may choose new targets in turn order. The last player who creates their copy controls the copy that will resolve first.

2011-01-22 : You can’t choose to pay any additional costs for the copy. However, effects based on any additional costs that were paid for the original spell are copied as though those same costs were paid for the copy too. For example, if the enchanted player sacrifices a 3/3 creature to cast Fling, each copy of Fling will also deal 3 damage.