I wanted to post this in here to address the question and because I think people have forgotten about this board. First situation: "have no effect on game state" bench switch Consider that you have a Pikachu active and another Pikachu on the bench that is in every way the same as the active one, such as damage counters, turns in play, etc. Playing Tate and Liza in this way to switch the Pikachu is a legal play and can be done. However, if you take too long to perform this kind of action, because the play does not advance the game in any way, you may get looks regarding slow play because if you are performing the action slowly then you are taking time off the clock. Second situation: "have no effect on game state" shuffle Consider that you have a zero card deck and after you play Tate and Liza you then have 5 cards remaining in your hand. It is a legal play to shuffle those 5 cards into the deck and then draw the 5 cards. Again, as in situation 1, if you take too long to perform this kind of action--you get more allowance to shuffle the deck than switch a pokemon--you may get looks regarding slow play because you are taking time off the clock. There are cards that do effects based on hand size so a judge should not penalize the action without knowing the details of your deck. Situation 5 below would override this. Third situation: choosing bench switch does nothing If all you have is an active Pikachu, what happens when you play Tate and Liza and chooses bench switch? Assuming you clearly communicated your intention to bench switch and your opponent correctly said that you can't do that, you could ask your opponent to let you take it back. Take back requests are made to the opponent and a judge cannot force them to accept a take back. If the take back request is declined, the question goes to the judge. At league, you will likely find players who are there for practice and your take back request might be accepted. Some of the best players at league I have seen talk out "what if" scenarios at critical points in a game and rewind their own games to try something else or to "play it right" when they both agree the player made decision that was bad. At a tournament, you are working with a higher expectation of card knowledge and testing your skills. Players might allow a take back for any reason. A decline may be because "it is a tournament with the expectation of knowing the cards." A judge should look at the game and ask "If the game were a spectator and were watching the game, what would the game think is happening right now?" The answer: because there is nothing to switch, the game would think a hand shuffle was being attempted. The judge should have the player shuffle the hand and draw 5. Fourth situation: choosing hand shuffle noes nothing. Consider a zero card hand (after playing Tate and Liza) and zero card deck. Again, after applying all from the above in the third situation, a judge should look at the game and ask "If the game were a spectator and were watching the game, what would the game think is happening right now?" The answer: because there is nothing to to shuffle into the deck* and no cards to draw from the deck, the game would think a switch was being attempted. The judge should have the player switch the active pokemon with a bench pokemon. *A zero card hand can be shuffled into a deck with cards in it and that would be a legal play. Fifth situation: The card really does nothing You only have an active pokemon, you only have Tate and Liza in hand, you have no cards in your deck. Because you cannot play a card for no effect, the judge should be called to do a rewind: Tate and Liza goes back to your hand. Curiously, consider situation two: what if your opponent also has a zero card hand and you need a zero card hand in order to match hand size, allowing your Ability to make your energy cost 0 and then attack to win the game? In this very specific scenario, you would not be allowed to play Tate and Liza and your opportunity to win the game would be prevented by the rule "you cannot play a card for no effect." Making your hand -1 card is not an effect. Drawing cards is an effect and because you cannot do it, you cannot play the card. Thoughts? Especially on the fifth situation.