Sylvan Library has a unique effect that looks for “cards drawn this turn.” The problem is this: the game technically knows which cards you’ve drawn this turn, but if you already added them to any other cards you had in your hand, your opponent doesn’t know which were drawn this turn, and neither does the judge he or she just called (except in unusual circumstances involving a Thoughtseize last turn, or perhaps an Oracle of Mul Daya).
Here’s the Official ruling that has been handed down for Competitive REL events where Sylvan Library is legal: “Players will not have an option to return a card that can’t be proven to have been drawn this turn.” In other words, you’ll be forced to pay 8 life for the cards you can’t put back this turn.
So if you control a Sylvan Library, the best way to prevent this sort of problem is to simply keep the rest of your hand separate as you draw for your turn and for Sylvan Library. If the three cards never touch your other cards, it’s clear to everyone which cards were drawn this turn. If you forget to keep your regularly drawn card separate and just put it directly into your hand, but then remember your Sylvan Library trigger, you can still keep the two extra drawn cards separate. Then you can choose whether to pay life for those cards or put them back, but you won’t be able to put back the first card you drew since not everyone can be certain which one it is.
Today’s Tournament Tip written by Josh Stansfield